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Weight

Weight Management

Achieving and maintaining a healthy body weight is a serious public health problem and a source of distress for many Americans. Under standards developed by the National Institutes of Health, about 60% of American adults are overweight, including more than 20% who are obese.

Factors contributing to excess body fat

Much research has been done in an effort to pinpoint the cause of overweight and obesity. It appears, however, that body weight and body composition are determined by multiple factors that may vary with each individual.

Genetic Factors

Estimates of the genetic contribution of obesity vary widely, from about 5% to 40%. Research suggests a genetic component in the determination of body weight. However, hereditary influences must be balanced against the contribution of environmental factors. The tendency to develop obesity may be inherited, but the expression of this tendency is affected by environmental influences.
In other words, genes are not destiny.

    Physiological Factors

  1. Metabolism and Energy Balance: metabolism is the sum of all the vital processes by which food energy and nutrients are made available to and used by the body. Resting metabolic rate (RMR) is the energy required to maintain vital body functions. Exercise has a positive effect on metabolism. When people exercise, they slightly increase their RMR. They also increase their muscle mass, which is associated with a higher metabolic rate.
  2. Hormones: these play a role in the accumulation of body fat, especially in women. Hormonal changes at puberty, during pregnancy, and at menopause contribute to the amount and location of fat accumulation.
  3. Weight Cycling: repeatedly losing and regaining weight might be harmful to both overall health and to efforts at weight loss.

    Lifestyle Factors

  1. Eating behavior - The average calorie intake by Americans has increased by 100 to 300 calories per day over the past two decades.
  2. Physical Activity - These levels are declining. From driving to work, sitting all day, and then relaxing in front of the television in the evening, the daily caloric expenditure has gone down.
  3. Psychosocial Factors - Some people use food as a means of coping with stress and negative emotion.

Adopting a healthy lifestyle for successful weight management

When all the research has been assessed, it is clear that most weight problems are lifestyle problems. Looking at these problems in a historical context reveals why fad diets and other quick-fix approaches are not effective in reversing overweight. About 100 years ago, Americans consumed a diet very different from today's diet and got much more exercise as well. Americans now eat more calories, fat, and refined sugars and fewer complex carbohydrates. Americans today also get far less exercise than their great-grandparents did.

Permanent weight loss is not something you start and stop. You need to adopt healthy behaviors that you can maintain throughout your life.

    Lifestyle Changes

  1. Total Calories: The best approach for weight loss is probably combining an increase in physical activity with moderate calorie restriction. Don't go on a "crash diet." To lose weight, you must decrease your calorie intake and/or increase the number of calories you burn.
  2. Portion sizes: over consumption of total calories is closely tied with portion sizes. Many people are unaware that the portion sizes of packaged foods and of foods served at restaurants have increased in size, and most of us significantly underestimate the amount of food we eat.
  3. Energy (calorie) density: pay attention to "energy density" - that is the number of calories per ounce or gram of weight in a food. Foods that are low in energy density have more volume and bulk.
  4. Fat calories: some fat is needed in the diet to provide essential nutrients, but avoid overeating fatty foods.
  5. Complex carbohydrates: these come from sources such as vegetables, legumes and whole grains. These foods help provide a feeling of fullness that can keep you from overeating.
  6. Simple sugars and refined carbohydrates: foods high in added simple sugars provide calories but few nutrients. Avoid or minimize consumption of these foods and substitute complex carbohydrates, such as those found in fruits and vegetables.
  7. Protein: the typical American diet has more than enough protein. If you eat a high protein diet, the immediate weight loss is likely water since such diets cause an immediate and rather dramatic loss of body fluid.
  8. Eating habits: eat small, more frequent meals on a dependable, regular schedule. Skipping meals leads to excessive hunger and feelings of deprivation.

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