What is the role of diet in the treatment of obesity?

The first goal of dieting is to stop further weight gain. The next goal is to establish realistic weight loss goals. While the ideal weight is a BMI of 20-25, this is difficult to achieve for many people. Thus success is higher when a goal is set to lose 10% to15% of baseline weight as opposed to 20% to 30% or higher. It is also important to remember that any weight reduction in an obese person would result in health benefits.

One effective way to lose weight is to eat fewer calories. One pound is equal to 3500 calories. In other words, you have to burn 3500 more calories than you take-in to lose one pound. Most adults need between 1200- 2800 calories/day-depending on body size & activity level to meet the body’s energy needs.

If you skip that bowl of ice cream, then you will be one-seventh of the way to losing that pound! Losing one pound per week is a safe & reasonable way to get off those extra pounds. The higher the initial weight of a person, the more quickly he/she will achieve weight loss. This is because for every one-kilogram (2.2 pounds) of body weight, approximately 22 calories are required to maintain that weight. So for a woman weighing 100 kilograms (220 pounds), he or she would require about 2200 calories a day to maintain his or her weight while a person weighing 60 kilograms (132 pounds) would require only about 1320 calories. If both ate a calorie-restricted diet of 1200 calories per day, the heavier person would loose weight faster. Age also is a factor in calorie expenditure. Metabolic rate tends to slow as we age, so the older a person is, the harder it is to lose weight.

There is controversy in regard to carbohydrates and weight loss. When carbohydrates are restricted, people often experience rapid initial weight loss within the first two weeks. This weight loss is due mainly to fluid loss. When carbohydrates are added back to the diet, weight gain often occurs, simply due to a regain of the fluid.

Exercise precautions:

The following people should consult a doctor before vigorous exercise:

     
  • Men over age 40 or women over age 50.  
  • Individuals with heart or lung disease, asthma, arthritis, or osteoporosis.  
  • Individuals who experience chest pressure or pain with exertion, or who develop fatigue or shortness of breath easily.  
  • Individuals with conditions that increase their risk of developing coronary heart disease, such as high blood pressure, diabetes, cigarette smoking, high blood cholesterol, or having family members with early onset heart attacks and coronary heart disease.

General diet guidelines for achieving and (as importantly) maintaining a healthy weight:

     
  • A safe and effective long-term weight reduction and maintenance diet has to contain balanced, nutritious foods to avoid vitamin deficiencies and other diseases of malnutrition.  
  • Eat more nutritious foods that have “low energy density.” Low energy dense foods contain relatively few calories per unit weight (fewer calories in a large amount of food). Examples of low energy dense foods include vegetables, fruits, lean meat, fish, grains, and beans. For example, you can eat a large volume of celery or carrots without taking in many calories.  
  • Eat less “energy dense foods.” Energy dense foods are high in fats and simple sugars. They generally have a high calorie value in a small amount of food. The United States government currently recommends that a healthy diet should have less than 30% fat. Fat contains twice as many calories per unit weight than protein or carbohydrates. Examples of high-energy dense foods include red meat, egg yolks, fried foods, high fat/sugar fast foods, sweets, pastries, butter, and high fat salad dressings. Also cut down on foods that provide calories but very little nutrition, such as alcohol, non-diet soft drinks and many packaged high calorie snack foods.  
  • About 55% of calories in the diet should be from complex carbohydrates. Eat more complex carbohydrates such as brown rice, whole-grain bread, fruits and vegetables. Avoid simple carbohydrates such as table sugars, sweets, doughnuts, cakes, and muffins. Cut down on non-diet soft drinks-these sugary soft drinks are loaded with simple carbohydrates and calories. Simple carbohydrates cause excessive insulin release by the pancreas, and insulin promotes growth of fat tissue.  
  • Educate yourself in reading food labels, estimating calories and serving sizes.  
  • Consult your doctor before starting any dietary changes. You doctor should prescribe the amount of daily calories in your diet.

What is the role of medication in the treatment of obesity?

Medication treatment of obesity should be used only in patients who have health risks related to obesity. Medications should be used in patients with a BMI greater than 30 or in those with a BMI of greater than 27 who have other medical conditions (such as high blood pressure, diabetes, high blood cholesterol) that put them at risk for developing heart disease. Medications should not be used for cosmetic reasons.

Like diet and exercise, the goal of medication treatment has to be realistic. With successful medication treatment, one can expect an initial weight loss of at least 5 pounds during the first month of treatment, and a total weight loss of 10-15% of the initial body weight. It is also important to remember that these medications only work when they are taken. When they are discontinued, weight gain can occur.

The first class (category) of medication used for weight control cause symptoms that mimic the sympathetic nervous system. They cause the body to feel “under stress” or ” nervous”. As a result, the major side effect of this class of medication is high blood pressure. This class of medication includes sibutramine (Meridia) and phentermine (Fastin, Adipex P). These medications also decrease appetite and create a sensation of fullness. Hunger and fullness (satiety) are regulated by brain chemicals called neurotransmitters. Examples of neurotransmitters include serotonin, norepinephrine, and dopamine. Anti-obesity medications that suppress appetite do so by increasing the level of these neurotransmitters at the junction (called synapse) between nerve endings in the brain.

Provided by ArmMed Media
Revision date: June 22, 2011
Last revised: by Sebastian Scheller, MD, ScD