Weight management

Definitions

Weight management refers to a set of practices and behaviors that are necessary to keep one's weight at a healthful level. It is preferred to the term "dieting," because it involves more than regulation of food intake or treatment of overweight people. People diagnosed with eating disorders who are not obese or overweight still need to practice weight management. Some health care professionals use the term "nutritional disorders" to cover all disorders related to weight.

The term "weight management" also reflects a change in thinking about treatment of obesity and overweight during the past 20 years. Before 1980, treatment of overweight people focused on weight loss, with the goal of helping the patient reach an "ideal weight" as defined by standard life insurance height-weight charts. In recent years, however, researchers have discovered that most of the negative health consequences of obesity are improved or controlled by a relatively modest weight loss, perhaps as little as 10% of the patient's body weight. It is not necessary for the person to reach the "ideal" weight to benefit from weight management. Some nutritionists refer to this treatment goal as the "10% solution." Secondly, the fact that most obese people who lose large amounts of weight from reduced-calorie diets regain it within five years has led nutrition experts to emphasize weight management rather than weight loss as an appropriate outcome of treatment.

Overweight and obese

Overweight and obese are not the same thing. People who are overweight weigh more than they should compared with set standards for their height. The excess weight may come from muscle tissue, body water, or bone, as well as from fat. A person who is obese has too much fat in comparison to other types of body tissue; hence, it is possible to be overweight without being obese.

There are several ways to determine whether someone is obese. Some measures are based on the relationship
between the person's height and weight. The older measurements of this correlation are the so-called height-weight tables that list desirable weights for a given height. A more accurate measurement of obesity is body mass index, or BMI. The BMI is an indirect measurement of the amount of body fat. The BMI is calculated in English measurements by multiplying a person's weight in pounds by 703.1, and dividing that number by the person's height in inches squared. A BMI between 19 and 24 is considered normal; 25–29 is overweight; 30–34 is moderately obese; 35–39 is severely obese; and 40 or higher is defined as morbidly obese. More direct methods of measuring body fat include measuring the thickness of the skin fold at the back of the upper arm, and bioelectrical impedance analysis (BIA). Bioelectrical impedance analysis measures the total amount of water in the body using a special instrument that calculates the different degrees of resistance to an electrical current in different types of body tissue. Fatty tissue has a higher resistance to the current than body tissues containing larger amounts of water. A higher percentage of body water indicates a greater amount of lean tissue.

Eating disorders

Eating disorders are a group of psychiatric disturbances defined by unhealthy eating or weight management practices. Anorexia nervosa is an eating disorder in which persons restrict their food intake severely, refuse to maintain a normal body weight, and express intense fear of becoming obese. Bulimia nervosa is a disorder marked by episodes of binge eating followed by attempts to avoid weight gain from the food by abusing laxatives , forcing vomiting, or overexercising. A third type, binge eating disorder, is found in some obese people, as well as in people of normal weight. In binge eating disorder, the person has an eating binge but does not try to get rid of the food after eating it. Although most patients diagnosed with anorexia or bulimia are women, 40% of patients with binge eating disorder are men.

Purpose

The purpose of weight management is to help each patient achieve and stay at the best weight possible the context of overall health, occupation, and living situation. A second purpose is the prevention and treatment of diseases and disorders associated with obesity or with eating disorders. These disorders include depression and other psychiatric disturbances, in addition to the physical problems associated with nutritional disorders.

Demographics and statistics

Obesity has become a major public health concern in the United States in the last decade. As of 2003, obesity ranks second only to smoking as a major cause of preventable deaths. It is estimated that 300,000 people die in the United States each year from weight-related causes. The proportion of overweight adults in the general population has continued to rise since the 1960s. About 34% of American adults, or 58 million people, are overweight, compared with 25% in 1980. In addition, there has been a 42% increase in the rate of childhood obesity since 1980.

The prevalence of obesity in the United States varies somewhat according to sex, age, race, and socioeconomic status. Among adults, 35% of women are considered obese, compared to 31% of men. The rate of obesity increases as people get older; those aged 55 or older are more than twice as likely to be obese as those in their twenties. African American men have the same rate of obesity as Caucasian men; however, African American women are almost twice as likely as Caucasian women to be obese by the time they reach middle age. The same ratio holds true for socioeconomic status; people in the lowest third of the income and educational level distribution are twice as likely to be obese as those with more education and higher income.

From the economic standpoint, obesity costs the United States over $100 billion each year. This amount includes the direct costs of hospital care and medical services, which come to $45.8 billion annually, or 6.8% of all health care costs. Another $18.9 billion represents the indirect costs of obesity, such as disabilities related to overweight or work days lost to obesity-related illnesses.

Obesity is considered responsible for:

• 88–97% of cases of type 2 diabetes
• 57–70% of cases of coronary heart disease
• 70% of gallstone attacks
• 35% of cases of hypertension
• 11% of breast cancers
• 10% of colon cancers

In addition, obesity intensifies the pain of osteoarthritis and gout; increases the risk of complications in pregnancy and childbirth; contributes to depression and other mental disorders; and makes a person a poor candidate for surgery. Many surgeons refuse to operate on patients who weigh more than 300 lb (136 kg).

Although fewer people suffer from eating disorders than from obesity, the National Institutes of Mental Health (NIMH) reports that 10 million adults in the United States meet the diagnostic criteria for anorexia or bulimia. Although eating disorders are stereotyped as affecting only adolescent or college-aged women, as of 2003 at least 10% of people with eating disorders are males—and the proportion of males to females is rising. Moreover, the number of women over 45 years of age who are diagnosed with eating disorders is also rising; many doctors attribute this startling new trend to fear of aging, as well as fear of obesity.

The long-term health consequences of eating disorders include gum disease and loss of teeth, irregular heart rhythm, disturbances in the chemical balance of the blood, and damage to the digestive tract. At least 50,000 people die each year in the United States as the direct result of an eating disorder; anorexia is the leading cause of death in women between the ages of 17 and 25.

Description

To understand the goals and structure of nutritionally sound weight management programs, it is helpful to look first as the causes of being overweight, obesity, and eating disorders.

Causes of nutrition-related disorders

genetic/biologic. Studies of twins separated at birth and research with genetically altered mice have shown that there is a genetic component to obesity. Some researchers think that there are also genetic factors involved in eating disorders.

lifestyle-related. The ready availability of relatively inexpensive, but high-caloric snacks and "junk food" is considered to contribute to the high rates of obesity in developed countries. In addition, the fast pace of modern life encourages people to select quick-cooking processed foods that are high in calories, rather than making meals that are more healthful but take longer to prepare. Lastly, changes in technology and transportation patterns mean that people today do not do as much walking or hard physical labor as earlier generations did. This sedentary, or inactive lifestyle makes it easier for people to gain weight.

sociocultural. In recent years, many researchers have examined the role of advertising and the mass media in encouraging unhealthy eating patterns. On the one hand, advertisements for such items as fast food, soft drinks, and ice cream, often convey the message that food can be used to relieve stress, reward, or comfort oneself, or substitute for a fulfilling human relationship. On the other hand, the media also portray unrealistic images of human physical perfection. Their emphasis on slenderness as essential to beauty, particularly in women, is often cited as a major factor in the increase of eating disorders over the past three decades.

Another sociocultural factor that contributes to obesity among some Hispanic and Asian groups is the belief that children are not healthy unless they look plump. Overfeeding in infancy and early childhood, unfortunately, makes weight management in adolescence and adult life much more difficult.

medications. Recent research has found that a number of prescription medications can contribute to weight gain. These drugs include steroid hormones, antidepressants, benzodiazepine tranquilizers, lithium, and antipsychotic medications.

Aspects of weight management

Since the late 1980s, nutritionists and health care professionals had come to recognize that successful weight management programs have three characteristics, as follows:

• They present weight management as a lifetime commitment to healthful patterns of eating and exercise , rather than emphasize strict dieting alternating with carelessness about eating habits.
• They are tailored to each person's age, general health, living situation, and other individual characteristics.
• They recognize that the emotional, psychological, and spiritual facet of human life are as important to maintaining a healthy lifestyle as the medical and nutritional facets.

Nutrition

The nutritional aspect of weight management programs includes education about healthful eating, as well as modifying the person's food intake.

dietary regulation. Most weight-management programs are based on a diet that supplies enough vitamins and minerals; 50–63 grams of protein each day; an adequate intake of carbohydrates (100 g) and dietary fiber (20–30 g); and no more than 30% of each day's calories from fat. Good weight-management diets are intended to teach people how to make wise food choices and to encourage gradual weight loss. Some diets are based on fixed menus, while others are based on food exchanges. In a food-exchange diet, a person can choose among several items within a particular food group when following a menu plan. For example, if a person's menu plan allows for two items from the vegetable group at lunch, they can have one raw and one cooked vegetable, or one serving of vegetable juice along with another vegetable. More detailed information about these and other weight-management diets is available in a booklet from the Weight Information Network of the National Institutes of Health, called Weight Loss for Life, listed under "Resources" below.

nutritional education. Nutritional counseling is important to successful weight management because many people, particularly those with eating disorders, do not understand how the body uses food. They may also be trying to manage their weight in unhealthy ways. One recent study of adolescents found that 32% of the females and 17% of the males were using such potentially dangerous methods of weight control as smoking, fasting, over-the-counter diet pills, or laxatives.

Exercise

Regular physical exercise is a major part of weight management because it increases the number of calories used by the body and because it helps the body to replace fat with lean muscle tissue. Exercise also serves to lower emotional stress levels and to promote a general sense of well-being. People should consult a doctor before beginning an exercise program, however, to make sure that the activity that interests them is safe relative to any other health problems they may have. For example, people with osteoarthritis should avoid high-impact sports that are hard on the knee and ankle joints. Good choices for most people include swimming, walking, cycling, and stretching exercises.

Psychological/psychiatric

Both obesity and eating disorders are associated with a variety of psychiatric disorders, most commonly major depression and substance abuse. Almost all obese people feel harshly judged and criticized by others, and fear of obesity is a major factor in the development of both anorexia and bulimia. Many people find medications and/or psychotherapy to be a helpful part of a weight management program.

medications. In recent years, doctors have been cautious about prescribing appetite suppressants, which are drugs given to reduce the desire for food. In 1997, the Food and Drug Administration (FDA) banned the sale of two drugs: fenfluramine (known as "fen-phen") and phentermine when they were discovered to cause damage to heart valves. A newer appetite suppressant, known as sibutramine, has been approved as safe. Another new drug that is sometimes prescribed for weight management is called orlistat. It works by lowering the amount of dietary fat that is absorbed by the body. However, it can cause significant diarrhea.

People with eating disorders are sometimes given antidepressant medications, most often fluoxetine (Prozac) or venlafaxine, to relieve the symptoms of depression or anxiety that often accompany eating disorders.

cognitive-behavioral therapy. Cognitive-behavioral therapy (CBT) is a form of psychotherapy that has been shown to be effective in reinforcing the changes in food selection and eating patterns that are necessary to successful weight management. In this form of therapy, patients learn to modify their eating habits by keeping diaries and records of what they eat, what events or feelings trigger overeating, and any other patterns that they notice about their choice of foods or eating habits. They also examine their attitudes toward food and weight management, and work to change any attitudes that are self-defeating or interfere with a healthy lifestyle. Most CBT programs also include nutritional education and counseling.

weight-management groups. Many doctors and nutritional counselors suggest that patients attend a weight-management group for social support. Social support is essential in weight management, because many who suffer from obesity or an eating disorder struggle with intense feelings of shame. Many isolate themselves from others because they are afraid of being teased or criticized for their appearance. Such groups as Overeaters Anonymous (OA) or Take Off Pounds Sensibly (TOPS) help members in several ways: They help to reduce the levels of shame and anxiety that most members feel; they teach strategies for coping with setbacks in weight management; they provide settings for making new friends; and they help people learn to handle problems in their workplace or in relationships with family members.

Surgical

As of 2003, bariatric surgery is the most successful approach to weight management for people who are morbidly obese (BMI of 40 or greater), or severely obese with additional health complications. Surgical treatment of obesity usually results in a large weight loss that is successfully maintained for longer than five years. The most common surgical procedures for weight management are vertical banded gastroplasty (VBG), sometimes referred to as "stomach stapling," and gastric bypass . Vertical banded gastroplasty works by limiting the amount of food the stomach can hold, while gastric bypass works by preventing normal absorption of the nutrients in the food.

Complementary and alternative medicine (CAM) approaches

Some forms of complementary and alternative medicine are beneficial additions to weight management programs.

movement therapies. Movement therapies include a number of forms of exercise, such as tai chi, yoga, dance therapy, Trager work, and the Feldenkrais method. Many of these approaches help people improve their posture and move their bodies more easily as well as keeping active. Tai chi and yoga, for example, are good for people who must avoid high-impact physical workouts. Yoga can also be adapted to a person's individual needs or limitations with the help of a qualified teacher following a doctor's recommendations. Books and videos on yoga and weight management are available through most bookstores or the American Yoga Association.

spiritual and religious practice. Prayer, meditation, and regular religious worship have been linked to reduced emotional stress in people struggling with weight issues. In addition, many people find that spiritual practice helps them to keep a healthy perspective on weight management, so that it does not crowd out other important interests and concerns in their lives.

herbal preparations. The one type of alternative treatment that people should be extremely cautious about making part of a weight management program is over-the-counter herbal preparations advertised as "fat burners," muscle builders, or appetite suppressants. Within a two-week period in early 2003, the national media carried accounts of death or serious illness from taking these substances. One is ephedra, a herb used in traditional Chinese medicine that can cause strokes, heart attacks, seizures, and psychotic episodes. The other is usnic acid, a compound derived from lichens that can cause liver damage.

Normal results

As of 2003, much more research needs to be done to improve the success of weight management programs. A position paper published by the American Dietetic Association in the summer of 2002 summarizes the present situation: "Although our knowledge base has greatly expanded regarding the complex causation of increased body fat, little progress has been made in long-term maintenance interventions, with the exception of surgery." Most adults in weight maintenance programs find it difficult to change eating patterns learned over a lifetime. Furthermore, their efforts are all too often undermined by friends or relatives, as well as by media messages that encourage overeating or the use of food as a mood-enhancing drug. More effective weight maintenance programs may well depend on broad-based changes in society.

Resources

books

american psychiatric association. "eating disorders." in diagnostic and statistical manual of mental disorders, 4th edition, text revision. washington, dc: american psychiatric association, 2000.

brownell, kelly, ph.d., and judith rodin, ph.d. the weight maintenance survival guide. dallas, tx: brownell & hager publishing co., 1990.

flancbaum, louis, m.d., with erica manfred and deborah biskin. the doctor's guide to weight loss surgery. west hurley, ny: fredonia communications, 2001.

hornbacher, marya. wasted: a memoir of anorexia and bulimia. new york: harper perennial editions, 1999.

" nutritional disorders: obesity." section 1, chapter 5 in the merck manual of diagnosis and therapy, edited by mark h. beers, m.d., and robert berkow, m.d. whitehouse station, nj: merck research laboratories, 1999.

pelletier, kenneth r., m.d. "cam therapies for specific conditions: obesity." in the best alternative medicine, part ii. new york: simon & schuster, 2002.

periodicals

bellafante, ginia. " when midlife seems just an empty plate." new york times, march 9, 2003 [cited march 12, 2003]. <www.nytimes.com/2003/03/09/health.html>.

chass, murray. "pitcher's autopsy points to ephedra as one factor." new york times, march 14, 2003 [cited march 14, 2003]. <www.nytimes.com/2003/03/14/sports/baseball/14base.html>.

cummings, s., e. s. parham, and g. w. strain. "position of the american dietetic association: weight management." journal of the american dietetic association 102 (august 2002): 1145-1155.

davis, r. b., and l. w. turner. "a review of current weight management: research and recommendations." journal of the american academy of nurse practitioners 13 (january 2001): 15-19.

drohan, s. h. "managing early childhood obesity in the primary care setting: a behavior modification approach." pediatric nursing 28 (november-december 2002): 599-610.

grady, denise. "seeking to shed fat, she lost her liver." new york times, march 4, 2003 [cited march 4, 2003]. <www.nytimes.com/2003/03/04/health.html>.

hanif, m. w., and s. kumar. "pharmacological management of obesity." expert opinion on pharmacotherapy 3 (december 2002): 1711-1718.

lowry, r., d. a. galuska, j. e. fulton, et al. "weight management goals and practices among u. s. high school students: associations with physical activity, diet, and smoking." journal of adolescent health 31 (august 2002): 133-144.

malhotra, s., k. h. king, j. a. welge, et al. "venlafaxine treatment of binge-eating disorder associated with obesity: a series of 35 patients." journal of clinical psychiatry 63 (september 2002): 802-806.

riebe, d., g. w. greene, l. ruggiero, et al. "evaluation of a healthy-lifestyle approach to weight management." preventive medicine 36 (january 2003): 45-54.

organizations

american dietetic association. (800) 877-1600. <www.eatright.org>.

american obesity association (aoa). 1250 24th street nw, suite 300, washington, dc 20037. (202) 776-7711 or (800) 98-obese. <www.obesity.org>.

american society for bariatric surgery. 7328 west university avenue, suite f, gainesville, fl 32607. (352) 331-4900. <www.asbs.org>.

american yoga association. <www.americanyogaassociation.org>.

overeaters anonymous (oa). world service office, p. o. box 44020, rio rancho, nm 87174-4020. (505) 891-2664. <www.oa.org>.

shape up america! c/o webfront solutions corporation, 15757 crabbs branch way, rockville, m. d. 20855. (301) 258-0540. <www.shapeup.org>.

weight-control information network (win). 1 win way, bethesda, md 20892-3665. (202) 828-1025 or (877) 946-4627.

other

national institutes of health, national institute of diabetes & digestive & kidney diseases (niddk). choosing a safe and successful weight-loss program. bethesda, md: niddk, 1998. nih publication no. 94-3700.

national institutes of health, national institute of diabetes & digestive & kidney diseases (niddk). do you know the health risks of being overweight? bethesda, md: niddk, 2001. nih publication no. 98-4098.

national institutes of health, national institute of diabetes & digestive & kidney diseases (niddk). weight loss for life. bethesda, md: niddk, 2002. nih publication no. 98-3700.

Rebecca Frey, Ph.D.

Weight loss

Definition

Weight loss/management is a term that defines not only a controlled plan for losing weight. It also implies that after individuals have lost the desired amount of weight, they will continue to maintain that weight by managing the weight loss—keeping off the pounds they lost. How many ways, and how many diet plans that might assist a senior adult in this venture are as individual as people themselves. Senior adults who suffer from diseases such as diabetes, heart disease , or kidney disease, have a vested interest in maintaining a proper weight due to complications that are linked to obesity . But this subject is of concern to any senior concerned about maintaining optimum health.

Description

The facts surrounding a diagnosis of obesity can be startling. Nine out of 10 people who are diagnosed with type 2 diabetes, also known as adult onset diabetes, are overweight. The optimum muscle mass that individuals typically have in their 20s is 45 per cent of total body weight. By the time that same population reaches the age of 70, that muscle mass decreased to 27 per cent. Even senior adults who are not overweight can have as much as 50% of their weight as fat.

The health risks that emerge when an individual is overweight, besides diabetes, include high blood pressure , high blood cholesterol, coronary heart disease, stroke , certain types of cancer , and gallbladder disease. Losing excess weight can be crucial to improving health, successful surgery and recovery from surgery, and minimizing the effects of diseases commonly associated with age such as arthritis, mobility issues , sleep apnea, fatty liver disease, and breathing difficulties—even those that are not directly related to coronary disease, emphysema , or asthma .

An unexplained, unplanned weight loss is cause for serious investigation. That is when even senior adults who might be overweight should immediately Weight loss make an appointment to see their physician. Sudden weight loss might be a sign of the onset of diabetes, cancer, or mental health issues such as Alzheimer's, dementia, or depression of which a person might not be fully aware. Once a weight loss occurs, either planned or unplanned, being underweight can also pose such health problems as increased risk for osteoporosis , decreased immunity, decreased muscle strength, hypothermia, constipation , and poor memory.

When any individual decides to lose weight, either at the recommendation of a personal physician or through concern for possible health complications, a careful diet/nutrition plan is addressed. Care must be taken to determine what is the best eating regimen for a person to follow depending on disease factors, medications, lifestyle, genetic and physiological factors, and the amount of excess weight to be lost.

Demographics

According to the National Center for Health Statistics, acting as a division of that Centers for Disease Control and Prevention, based on a 1999–2002 National Health and Nutrition Examination Survey, a population-based survey, 65 percent of adults in the United States over the age of 20 were overweight or obese, and 30 percent of all adults are obese. Institutes of Health Obesity Research Task Force, weight loss and obesity can become issues as people age even when they were not overweight as younger people.

For women in particular, during the years leading up to menopause , when increases in weight, and shifts in body weight begin to occur, an average of a pound a year is gained. According to information provided by the Mayo Clinic, however, it is not the normal shifts in hormone levels that are the only cause of weight gain. Factors that are more significant in weight gain include decreased physical activity, eating more, burning fewer calories, and genetic predisposition to certain kinds of weight gain. Breast cancer risk has also been found to be reduced when women maintain an appropriate weight.

The groundbreaking Framingham Heart Study, conducted by the National Heart, Lung, and Blood Institute (NHLBI) studied 4,000 white individuals from 1971 through 2001, aged 30 to 59. That study found that in middle age, following menopause, even those women who had maintained a healthy weight and were not considered overweight. For those already overweight, 16 to 23 percent would become obese within 4 years. For men, 12 to 13 percent of them were likely to become obese within that same time period.

As people age, the chances of increasing weight become greater due to decreased physical activity, poor eating habits, and medications.

Purpose

Losing weight during the senior adult years, and maintaining the weight loss provide many health and social benefits. It can decrease difficulty in mobility, the risk for diseases and conditions such as diabetes, coronary artery disease, gallbladder disease, high blood pressure, stroke, certain types of cancer, and high blood cholesterol—determined to be a factor in some heart conditions. A five to 10 percent weight loss alone can lower blood pressure, assist in maintaining lower blood sugar levels in diabetic individuals, increase mobility by easing pressure on otherwise painful joints, and provide more energy and motivation for social activities.

By the late twentieth century the body mass index , or BMI index, was developed as one way of determining whether an individual was overweight or obese. A BMI of 25–29.9 is considered overweight; and a calculation of 30 or greater, is obese.

BMI is only one tool in determining whether a person is overweight or obese. Because it does not measure body fat or muscle directly, people might have the same BMI but differ in their percentages of body fat. A muscle builder would typically average greater muscle to body fat percentages than most senior adults. Physicians are also concerned, especially with senior adults with how body fat is distributed. Any excess abdominal fat presents an increased risk factor for health. People who carry excess weight at that body location are more likely to develop obesity—relatd health issues. Women whose waists measure more than 35 inches, and men who measure more than 40 inches, are more likely to suffer health risks than those people with lower waist measurements—indicating that body fat is more evenly distributed throughout the body.

The most accurate measures of obesity involve weighing a person underwater, or in a chamber that uses air displacement to measure body volume, according to the Weight-control Information Network (WIN) of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health. In addition, an x-ray test known as the dual energy x-ray absorptionmetry, or DEXA. In fact, those most qualified to determine whether or not a person is overweight or obese is the personal physician who has the benefit of professional experience and guidelines that address the issue of weight. Standard charts—once the domain of insurance providers—are also available to present what an appropriate weight for a particular height and body frame might be. Again, though, seeking professional medical advice to determine levels of obesity constitutes the preferable approach.

QUESTIONS TO ASK YOUR DOCTOR

• How much do I have to exercise to lose weight, and maintain my weight loss?
• What harmful affects can any particular “popular” or “fad” diet have on my health?

Challenges

Any weight loss regimen should be discussed with an individual's physician. Hundreds of diets, many of them considered fad diets beckon to people with promises of quick and dramatic weight loss. The issue of losing weight can be particularly difficult in senior adults due to slower metabolisms, economic factors that pose a financial strain when purchasing healthy food items such as organic meats, fish, cheese, and fresh produce. Any diet plan that indicates people can lose a lot of weight quickly should be avoided. Losing two pounds a week during any diet is optimal for the body to adjust to weight loss, and ensures the likelihood of understanding how to maintain that loss throughout the coming years. Yet watching such a slow decrease in weight can provide frustration and temptation to veer off the course of the diet plan. The issue in any healthy weight loss plan is finding what works best for any individual, and what will be most likely to keep a person on a diet for the duration of the necessary weight loss. Dieting that is arduous and makes an individual feel hungry all the time can be a plan of self-sabotage from the beginning. Any individual setting out to lose weight should set a positive, and reasonable goal. The best diet plan is simply a healthy eating pattern, with smaller meals and overall fewer calories. When a person feels deprived, the chances for defeat are greater.

A weight loss study lead by Dr. Laura Svetkey, a professor of medicine at Duke University was published in the March 12, 2008, issue of the Journal of the American Medical Association. It followed almost 1,700 overweight or obese people, with the first phase of the program being a six-month weight loss program, with an average weight loss during that time of 19 pounds. The second phase randomly selected for three groups—a “personal contact” group, an “interactive technology” group, and a “self-directed” group. After 30 months, it was the group that had personal contact with other individuals who were either interested also in maintaining a weight loss, or individuals interested in helping the individuals maintain their weight loss, that regained 8.8 pounds less than the self-directed group. The “interactive technology” group regained an average of 3.3 pounds more than the group maintaining personal contacts. What this study might indicate is that support systems, while challenging to maintain, can be essential in maintaining weight loss.

Risks

A diet that emphasizes one particular food group might be tempting when discovering how much weight can be lost in such a short period of time. Seldom does the weight stay off—and the risk of sudden weight loss to health conditions can be life threatening. A decrease in calories should not mean a decrease in necessary nutrients. When approaching any change in eating habits, even when they are an improvement, attention to how those changes might be affected in relation to medications, physical activity, and mental health issues should also be considered. Risks can be minimized if following any diet in the care of a physician or registered dietician .

Losing weight is only part of the challenge in weight loss. Maintaining the weight post loss can be at risk if healthy eating patterns that satisfy both nutritional needs and emotional needs are not continued. The risk of a diet of deprivation almost ensures that most people will binge following a weight loss. Not only can that result in gaining back lost weight. It can trigger complications for disease conditions already present, particularly diabetes.

Taking diet pills without the advice of a physician, especially for senior adults with varying medical conditions can prove harmful. Bariatric surgery , another weight loss method involving gastrointestinal bypass methods, can pose risks to senior adults. Only can a team of medical professionals that include an individual's personal physician provide the best advice regarding the benefits of such a surgery as opposed to the risks.

KEY TERMS

BMI —The abbreviation for “Body Mass Index” calculating a figure to determine an individual's weight-height proportion and measure determining level of underweight, normal weight, overweight, or obesity.

Calorie —The unit of measure used to determine the amount of energy is produced by food when oxidized in the human body—every measured portion of food is assigned a certain calorie level. Suggestions for calorie intake for age, gender, and body weight in order to maintain weight are provided by the U.S. Food and Drug Adminstration.

Results

The success of any weight loss program offers numerous health and social benefits to senior adults, no matter what medical conditions might exist. Maintaining the weight loss through proper nutrition and healthful eating habits can provide protection for the immune system , help regulate diabetes, high blood pressure, and other coronary-related diseases, increase mobility for necessary physical activity, increase overall emotional well-being.

Resources

BOOKS

Zinczenko, David; and, Goulding, Matt. Eat This, Not That: Thousands of Simple Food Swaps that can save you 10, 20, 30 pounds-or more. Emmaus, PA and NY: Rodale Books. 2007

PERIODICALS

“Baby Boomers and Arthritis: Increasing Arthritis Linked to Higher Obesity Rates-Beth Israel Deaconess Medical Center study.” American Journal of Public Health. September 2007.

“Diabetes, Obesity, and Hypertension May Enhance Associations between Air Pollution and Markers of Systemic Inflammation.” Environmental Health Perspectives. July 2006. pp. 992–998.

“Snacking helps seniors fight weight loss.” NY Daily News. May 25, 2007.

OTHER

“Calorie restriction: Is this anti-aging diet worth a try?” http://www.mayoclinic.com/print/anti-aging/HQ00223/METHOD=pri…

“Eating Well As We Age.” http://www.www.fda.gov/opacom/lowlit/eatage.html

“Embrace Your Health! Lose Weight if You Are Overweight.” http://www.win.niddk.nih.gov/health/public/heart/other/chdblack/embrace1.htm

“Good Nutrition: It's a Way of Life.” http://www.niapublications.org/agepages/nutrition.asp

“Losing Weight Safely.” http://www.www.fda.gov/opacom/lowlit/weightls.html

“Losing Weight: Start By Counting Calories.” http://www.www.fda.gov/fadc/features/2002/102_fat.html

“Obesity.” http://www.mayoclinic.com/print/obesity/DS00314/METHOD=pri…

“Personal Contact Helps Maintain Weight Loss.” http://www.nlm.nih.gov/medlineplus/print/news/fullstory_62090.html

“Understanding Adult Obesity.” http://www.win.niddk.nih.gov/publications/understanding.htm

“Weight Control.” http://www.nlm.nih.gov/medlineplus/print/weightcontrol.html

“Weight Gain After Menopause: Reverse the Middle age spread.” http://www.mayoclinic.com/print/menopause-weight-gain/HQ0107

“Young At Heart, Healthy Eating & Physical Activity Across Your Lifespan.” http://www.win.niddk.nih.gov

ORGANIZATIONS

American Diabetes Association, 1701 Beauregard Street, Alexandria, VA, 22311, 800–342–2383, http://www.ada.org.

American Dietetic Association, 120 South Riverside Plaza, Suite 2000, Chicago, IL, 60606–6995, 800–877–1600, http://www.eatright.org.

Mayo Clinic, 200 First Street, NW, Rochester, MN, 55905, 507–284–2511, http://www.mayoclinic.com.

National Institute on Aging, National Institutes of Health, Building 31, Room 5C27, 31 Center Drive, Bethesda, MD, 20892, http://www.nia.nih.org.

U.S. Food and Drug Administration, 5600 Fishers Lane, Rockville, MD, 20857–0001, 888–463–6332, http://www.fda.gov.

Weight-control Information Network (WIN)/National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, 1 WIN Way, Bethesda, MD, 20892-3665, 202-828-1025, 877-946-4627, 202-828-1028, [email protected], http://win.niddk.nih.gov.

Jane Elizabeth Spear

Weight loss

Definition

Weight loss is a reduction in body mass characterized by a loss of adipose tissue (body fat) and skeletal muscle.

Description

Unintentional weight loss is the most common symptom of cancer and often a side effect of cancer treatments. A poor response to cancer treatments, reduced quality of life, and shorter survival time may result from substantial weight loss. The body may become weaker and less able to tolerate cancer therapies. As body weight decreases, body functionality declines and may lead to malnutrition, illness, infection, and perhaps death.

Severe malnutrition is typically defined in two ways: functionally (increased risk of morbidity and/or mortality) and by degree of weight loss (greater than 2% per week, 5% per month, 7.5% per 3 months, and 10% per 6 months). Without considering a specific time course, grading is as follows:

• Grade 0 = less than 5.0% weight loss
• Grade 1 = 5.0% to 9.9%
• Grade 2 = 10.0% to 19.9%
• Grade 3 = greater than 20.0%
• Grade 4 (life-threatening) is not specifically defined. Paying attention to weight loss at an early stage is necessary to prevent deterioration of weight, body composition, and performance status.

Causes

There are many reasons for weight loss in cancer patients, including appetite loss because of the effect of cancer treatments (chemotherapy , radiation therapy , or biological therapy) or due to psychological factors such as depression . Patients may suffer from anorexia and lose desire to eat, and thus consume less energy. When inadequate calories are consumed, it can lead to "wasting" of body stores (muscle and adipose tissue). Weight loss may be temporary or may continue at a life-threatening pace.

Weight loss may be also be a consequence of an increased requirement for calories (energy) due to infection, fever , or the effects of the tumor or cancer treatments. If infection or fever is present, it is necessary to consider that there is an increased caloric need of approximately 10% to 13% per degree above 98.6°F (37°C). Therefore, energy intake has to be increased to account for this rise in body temperature.

Weight loss may be a result of a common problem in cancer called cachexia. Approximately half of all cancer patients experience cachexia, a wasting syndrome that induces metabolic changes leading to a loss of muscle and fat. It has been proposed that cachexia may be due to the effects of the tumor, but this is debatable considering some patients with very large tumors do not experience cachexia, while others do even though tumors are less than 0.01% of body mass. Cachexia is most common in patients with pancreatic and gastric cancer. Approximately 83% to 87% of these patients experience weight loss. Cachexia is characterized by symptoms such as a decreased appetite, fatigue , and poor performance status. It can occur in individuals who consume enough food, but due to disease complications, cannot absorb enough nutrients (i.e. fat malabsorption). Although energy expenditure is sometimes increased, cachexia can occur even with normal energy expenditure. Cachexia is multifactorial in nature and associated with mechanical factors, psychological factors, changes in taste, and cytokines. It should be distinguished from anorexia, where there is a loss of desire to eat, resulting in weight loss. Cachexia is serious in cancer patients, sometimes leading to death.

Special concerns

In order to allow normal tissue repair following aggressive cancer therapies, patients require adequate calories and macronutrients in the form of protein, carbohydrates, and fat. Inadequate consumption of food and/or poor nutrition may impair the ability of a patient to tolerate a specific therapy. If a low tolerance to therapy necessitates a decrease in dose, the therapy's effectiveness could be compromised. Wound healing may also be impaired with poor nutrition and inadequate energy intake.

Research has demonstrated that men often experience significantly more weight loss than women over the course of the disease and lose weight much faster. On average, survival time for men is shorter than for women. Significant predictors of patient survival are stage of disease, initial weight-loss rate, and gender.

Treatments

Nutritional problems related to side effects should be addressed to ensure adequate nutrition and prevent weight loss. In particular, cancer patients should maintain an adequate intake of calories and protein to prevent protein-calorie malnutrition. The patient's caloric requirements can be calculated by a dietitian or doctor since nutrient requirements vary considerably from patient to patient.

The following dietary tips may help to reduce weight loss:

• Eat more when feeling the hungriest.
• Eat foods that are enjoyed the most.
• Eat several small meals and snacks instead of three large meals. A regular meal schedule should be kept so meals are not missed.
• Have ready-to-eat snacks on hand such as cheese and crackers, granola bars, muffins, nuts and seeds, canned puddings, ice cream, yogurt, and hard boiled eggs.
• Eat high-calorie foods and high-protein foods.
• Take a small meal as to enjoy the satisfaction of finishing a meal. Have seconds if still hungry.
• Eat in a pleasant atmosphere with family and friends if desired.
• Make sure to consume at least eight to ten glasses of water per day to maintain fluid balance.
• Consider commercial liquid meal replacements such as Ensure, Boost, Carnation, and Sustacal.

An appetite stimulant may be given in order to prevent further weight loss such as megestrol acetate or dexamethasone . In clinical trials , both these medications appear to have similar and effective appetite stimulating effects with megestrol acetate having a slightly better toxicity profile. Fluoxymesterone has shown inferior efficacy and an unfavorable toxicity profile.

Alternative and complementary therapies

Depression may affect approximately 15% to 25% of cancer patients, particularly if the prognosis for recovery is poor. If anorexia is due to depression, there are antidepressant choices available through a physician. Counseling may be also be sought through a psychologist or psychiatrist to cope with depression.

It is important to check with a dietitian or doctor before taking nutritional supplements or alternative therapies because they may interfere with cancer medications or treatments. St. John's Wort has been used as a herbal remedy for treatment of depression, but it and prescription antidepressants is a dangerous combination that may cause symptoms such as nausea, weakness, and may cause one to become incoherent.

See Also Taste alteration

Resources

BOOKS

Keane, Maureen, et al. What to Eat If You Have Cancer: A Guide to Adding Nutritional Therapy to Your TreatmentPlan. Lincolnwood, IL: National Textbook Company/Contemporary Publishing Group, 1996.

Nixon, Daniel W., M.D., Jane A. Zanca, and Vincent T. DeVitaThe Cancer Recovery Eating Plan: The Right Foods to Help Fuel Your Recovery. New York: Times Books, 1996.

Quillin, Patrick, and Noreen Quillin. Beating Cancer With Nutrition—Revised. Sun Lakes, AZ: Bookworld Services, 2001.

PERIODICALS

Kant, Ashima, et al. "A Prospective Study of Diet Quality and Mortality in Women." JAMA 283, no. 16 (2000): 2109-15.

Loprinzi, C.L., et al. "Randomized Comparison of Megestrol Acetate Versus Dexamethasone Versus Fluoxymesteronefor the Treatment of Cancer Anorexia/Cachexia." Journal of Clinical Oncology 7, no. 10 (1999): 3299-306.

Roubenoff, Ronenn. "The Pathophysiology of Wasting in the Elderly." The Journal of Nutrition 129, no. 1 (1999):256-9.

Tisdale, Michael J. "Wasting in cancer." The Journal of Nutri tion 129, no. 1 (1999): 243-6.

ORGANIZATIONS

National Center for Complementary and Alternative Medicine (NCCAM). 31 Center Dr., Room #5B-58, Bethesda, MD20892-2182. (800) NIH-NCAM, Fax (301) 495-4957.<http://nccam.nih.gov>.

The National Cancer Institute (NCI). Public Inquiries Office:Building 31, Room 10A31, 31 Center Dr., MSC 2580, Betheseda, MD 20892-2580 (301) 435-3848, (800) 4-CANCER, <http://cancer.gov/publications/>, <http://cancertrials.nci.nih.gov>, <http://cancernet.nci.nih.gov>.

American Institute for Cancer Research. 1759 R Street NW, Washington, D.C. 20009. (800) 843-8114 or (202) 328-7744. <http://www.aicr.org>, e-mail: [email protected].

Crystal Heather Kaczkowski, MSc.

KEY TERMS

Anorexia

—A condition frequently observed in cancer patients characterized by a loss of appetite or desire to eat.

Cachexia

—A condition where the bodyweight "wastes" away, characterized by a constant loss of weight, muscle, and fat.

Cancer

—A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread through the bloodstream and lymphatic system to other parts of the body.

Chemotherapy

—Chemotherapy kills cancer cells using drugs taken orally or by needle in a vein or muscle. It is referred to as a systemic treatment due to fact that it travels through the bloodstream and kills cancer cells outside the small intestine.

Enteral nutrition

—Feedings administered through a nose tube (or surgically placed tubes) for patients with eating difficulties.

Parenteral nutrition

—Feeding administered most often by an infusion into a vein. It can be used if the gut is not functioning properly or due to other reasons that prevent normal or enteral feeding.

Protein-calorie malnutrition

—A lack of protein and calories are consumed to sustain the body composition, resulting in weight loss and muscle wasting.

Radiation therapy

—Also called radiotherapy; uses high-energy rays to kill cancer cells.

Wasting

—When inadequate calories are consumed, it can lead to "wasting" or depletion of body mass. Wasting results in weight loss in tissues such as skeletal muscle and adipose tissue (fat).

Weight Loss

Weight loss and the strategies advertised as achieving weight loss are a remarkable example of human nature at its most capricious. It seems that a large percentage of the adult population of modern Western culture is prepared to seek and pursue a weight loss solution, in the midst of societies where fast foods rich in saturated fats, sugared beverages, and generally unhealthy physical habits reign supreme.

The advertising campaigns in support of commercially advocated weight loss schemes that regularly appear in North America appeal primarily to the vanity of the individual. The scientific imperatives behind weight loss are far starker and far more compelling than if one looks attractive. Excess body weight impacts human performance in a multitude of ways, all of which are serious. There has been a flood of statistical data in recent years to support various campaigns aimed at addressing the lack of fitness people of all ages. Governmental and private organizations throughout the world have highlighted the rise in the incidence of overweight and obese children, and the predicted crippling public cost of the additional health care that will be necessitated by the consequences of obesity in adults.

Weight loss strategies are compelling in the face of this data. Aircraft, movie theater, and sports stadium seating is now too narrow to accommodate the typical modern North American adult. The incidence of diabetes, osteoarthritis, cardiovascular illnesses (including high cholesterol), coupled with the doubling of rates of adult and juvenile obesity (generally defined as when the percentage of body fat in a given individual exceeds 30%), have lead researchers to conclude that the present generation of young people (those born after 1985) may be the first generation in recorded history to experience a shorter lifespan than that of their parents.

The Office of the Surgeon General of the United States estimated in 2006 that 300,000 Americans die every year as a result of complications stemming from obesity, with childhood obesity increasing 230% since 1980. It is further estimated that 62% of all Americans are overweight.

From a physiological perspective, weight loss is a simple proposition, and the negative health consequences of excess body weight are consequently significantly reduced. The body has two basic structural components when assessing the ideal weight for any individual. Lean body mass is the weight of the body's skeleton, organs, and muscle. Body fat is the product of the food consumed through diet that is not immediately required by the body for energy. Stored as triglycerides in the specialized fat storage cells known as adipose tissue, body fat plays an important role as a reserve energy source, as well as insulation for the more vulnerable internal organs. While excess body fat is an unhealthy physical state, small percentages of body fat are desirable; healthy males, depending on their age, physical build, and the nature of sports activities, will possess a body fat percentage of between 10% and 15%, while females naturally possess greater amounts of body fat, and a healthy woman may possess between 16% and 20%.

One pound of body fat represents stored energy in the body of 3,500 calories. To lose weight at a rate of 1.5 lb per week (a figure often cited as a safe rate of weight loss), the person must either reduce food consumption or increase the level of physical activity by a total of 750 calories per day (5,250 ÷ 7).

The weight loss issues faced by athletes are not generally as dramatic as those for members of the general population. Most athletes who perceive a need to reduce their weight have a specific athletic objective that is measurable, such as being able to finish a training run, or lift a specific amount of weight. When the athlete is actively engaged in a sport, but seeks to reach a perceived ideal weight for competitive purposes, the formulation of a weight loss plan must include the following components: targeted ideal weight; current weight; and level of fitness, including body fat and lean muscle mass, physical conditioning factors (such as preexisting health concerns), and the anticipated competitive schedule.

For active athletes seeking to achieve a reduction in their current weight to a desired weight, rapid reductions in weight are usually not healthy nor do they enhance their present athletic ability. To maintain a minimum level of fitness, the athletes must continue to train at their current level, or even harder during an active period of weight loss. Training requires careful attention to the athletes' nutritional needs, and a reduction in food intake. Additionally, increased training creates a risk of nutritional deficits. Using the calculation of the energy contained in one pound of body fat, an athlete could continue with a normal diet (subject to an analysis of the nutritional issues that may have lead to the weight gain), and lose weight through increased training alone.

The multitude of commercial diets, particularly those that promote low carbohydrate intake, must be approached with considerable caution by an athlete seeking to lose weight. In a typical balanced diet, the body will receive 60-65% of its energy sources in the form of carbohydrates, 12-15% as proteins, and less than 30% as fats. Carbohydrates are the preferred energy source for many types of human functions, including those of the brain and the nervous system. Purported low-carbohydrate diets proceed on the proposition that when the body has limited carbohydrates available, it will naturally turn to its fat stores as an alternative. If the only concern were the accessing of fats, this diet might operate as intended. However, athletes and the energy pathways (anaerobic, anaerobic alactic, and aerobic) used by the body to power muscular function only operate optimally when the energy stores are compatible.

A further difficulty for the athlete on the low-carbohydrate diet is the fact that many micronutrients (including all vitamins and most minerals) and phytochemicals tend to be most prolific and readily absorbed into the body through carbohydrates such as fruits and vegetables. Weight loss without a corresponding maintenance of nutritional health is an undesirable state of any athlete.

There are a number of specific weight loss scenarios that carry significant psychological issues. Eating disorders are prevalent among young females, a demographic where concerns over body image are often a motivation to extreme diets. Among female athletes, the sports of gymnastics, diving, and figure skating emphasize physical presentation and appearance, to the extent where, in some circumstances, the athletes will convince themselves that their body is inadequate for competition. The mental illnesses of bulimia and anorexia nervosa are the best known of these disorders. Bulimia is a condition where the athlete will commonly eat and purge, apparently consuming regular quantities of food, but eliminating meals through either vomiting or the use of laxatives. Anorexia nervosa is a self-imposed starvation to achieve thinness; anorexia can be fatal.

Weight loss supplements, fat burners, and so-called diet pills are sometimes touted as fast-acting remedies to assist in the elimination of excess weight. As with many of the products sold commercially as weight loss supplements, there are nuggets of factual science-based material buried among the claims of speedy, effortless weight loss. The first of the common and truthful representations made is that the determination of the basal metabolic rate (BMR) for every individual is important in the development of a weight loss strategy. The BMR is an expression of how much energy an individual consumes in a given day. The BMR will fall within a range for all persons, generally in relation to their body type. There are three generally recognized body types: the ectomorph (thin, smaller bones build), the endomorph (the rounder, stouter build), and the mesomorph (larger, more muscular build).

Many of the fat burner supplements have thermogenic qualities, meaning that they will increase the BMR of an individual to a limited degree by increasing the energy generated by the body and stimulate the metabolism. As with any nutritional supplement, knowing exactly what is contained in the formulation will indicate whether the product will promote or assist in weight loss in a safe manner. A number of weight loss products include known stimulants such as ephedra or ma huang (containing ephedrine), caffeine (including herbs such as guarana), bitter orange, and similar substances. Stimulants tend to act as an appetite suppressant through their action on the central nervous system, with a corresponding elevation of blood pressure and heart rate. An athlete engaged in physical activity must be cautious regarding the consumption of such products, given the stress produced by training alone on various bodily systems. Ephedrine has been the subject of worldwide controversy in all manner of herbal formulations, as there is considerable evidence that ephedrine played a role in a significant number of cases involving heart attacks, increased high blood pressure, and strokes. It is clear that ephedrine and caffeine consumed together heighten user risk.

There is little question from a scientific standpoint that the best weight loss programs are those that simply combine exercise and a reduction of calories in diet, without compromising nutrition.

see also Diet; Eating disorders in athletes; Fat burners; Metabolic response; Muscle mass and strength; Obesity; Weight gain.

Weight Loss Diets

With over 50 percent of the population of the United States and other industrialized countries being either overweight or obese , a great number of people want to lose weight. However, weight loss is not easy—and not often successful.

Weight gain is a result of consumed energy in the form of high-calorie foods eaten in excess of the body's need for energy. An adult's body needs energy to provide for its physiological functions, including heart, kidney, and liver function; blood circulation; respiration; muscle tone; and constant body temperature, called basal metabolic rate (BMR), as well as the energy spent in physical activity. An adult woman who is moderately active needs about 2,000 calories per day to meet all her nutrient requirements and maintain a healthy weight. She must therefore choose her diet carefully, avoiding fast foods and any other high-fat, high-sugar foods, eating a variety of fruits, vegetables, and whole-grain foods, and exercising regularly to avoid depositing excess body fat.

When energy consumption exceeds energy expenditure, excess energy is stored as fat in the body. A person usually gains weight gradually, adding less than a pound per month depending on the level of physical activity and amount and type of food eaten. It is very unusual to gain weight suddenly or at a faster rate than one pound per week. To be successful, the weight loss must also be gradual. Weight loss of one to two pounds per week is recommended, accompanied by a nutrient-dense diet with adequate amounts of high-fiber, whole-grain foods, and exercise.

In any weight loss attempt the goal is to lose the excess fat that has been accumulated in the body, rather than to lose weight. Therefore, strategies must be chosen carefully to achieve the goal of losing fat. Research has proven that the only long-term way to reduce body fat (and not body protein and water, which can be quick but ineffective) is to reduce the intake of high-fat and sugary foods and to exercise regularly. A successful weight loss diet must include adequate amounts of all essential nutrients that the body needs to maintain health. It is important to reduce the fat and concentrated carbohydrates (sugar, candy, high-fat and high-sugar desserts, fried foods, fatty meats, and whole-fat dairy products) in the diet, to reduce the intake of red meat and cheese as much as possible, and to avoid soft drinks (soda) and alcohol. However, if such a diet contains less than 1,600 calories per day, health will be compromised. It is also important to exercise regularly (at least thirty minutes per day, or more if the goal is to lose fat faster).

In spite of reports appearing in popular news magazines and newspapers on high-protein diets, scientific researchers in the field of nutrition believe that although high-protein diets may reduce food intake by inducing early satiety and increasing the thermic effect of foods temporarily, the long-term possibility of kidney problems, bone mineral loss, and other unknown long-term risk factors make these diets unsuitable for weight loss.

Losing weight at a rate of about one to two pounds per week is safe and doable. It takes a deficit of about 3,500 calories to lose a pound of weight, which can be accomplished in a week by cutting out 500 Kcalories per day. However, a young girl who eats 2,000 calories a day and cuts back to 1,500 calories per day may end up being deficient in iron and calcium . A better strategy would be to reduce calorie intake by 250 and burn the other 250 through exercise. That would equal about three miles of race walking or thirty minutes of bicycling each day. With this strategy, a very adequate, balanced, and normal diet can be followed—one that provides all the necessary nutrients. Individuals can vary the foods they eat without getting tired of "being on a diet." Developing a regular exercise habit will not only aid weight loss but will help a person feel better.

Fad Diets and Weight Cycling

Many fad diets promise fast weight loss with little effort. However, any program that offers quick and easy results must be viewed with suspicion. If there were any way to easily lose weight there would not be so many over-weight and obese people around. Many people fall for these promises and start to lose weight (not fat), but they soon become tired or give themselves a vacation from dieting and gain the lost weight back, plus some more. Remembering their initial weight loss, they then go back on the diet and lose some of the gained weight, but not all of it. Repeating this cycle several times they end up gaining weight because each time they went off the diet they gained a little more weight than what they had lost.

This practice is called "weight cycling" or "yo-yo dieting." As an individual starts reducing his or her food energy intake, body cells sense the reduced energy and nutrients and start economizing in terms of energy expenditure in BMR. Therefore, less heat is produced by the body and less involuntary activity and physiological functioning are performed. As soon as the individual resumes his or her pre diet food habit, more fat is deposited in the body, resulting in a faster rate of weight gain. Repeating this cycle a few times results in a net weight gain rather than weight loss. Under these conditions the body composition also changes, and the percentage of body fat is increased. This increases the risk of degenerative diseases such as obesity , type II diabetes , cardiovascular disease, hypertension , and cancer .

In order to avoid these problems, an individual interested in losing weight should follow these recommendations:

• Do not believe or follow any of the fad diets that promise easy and quick weight loss, because there is no such thing.
• Combine weight reduction programs with exercise, which not only utilizes more energy, but also increases lean body tissue (muscle fibers), which in turn increases BMR.
• Make sure that one's diet is varied, adequate in all essential nutrients, and includes adequate numbers of servings of fruits, vegetables, and whole-grain products.
• Try to lose body fat rather than body weight by following an exercise program that includes resistance training as well as aerobic activity.
• Be patient and lose weight gradually. Remember, weight gain did not happen fast, and neither will weight loss.
• Avoid weight cycling.

see also Dieting; Fad Diets; Obesity; Yo-Yo Dieting.

Simin B. Vaghefi

Bibliography

Eisenstein, J.; Roberts, S.; Dallal, G.; and Saltzman, E. (2002). "High-Protein Weight-Loss Diets: Are They Safe and Do They Work? A Review of the Experimental and Epidemiological Data." Nutrition Review 60:189–197.