9.4 Healthy Long Term Weight Management

Based on recommendations from the National Institutes of Health (NIH), individuals who are obese should aim to lose about 10% of their body weight over a six month period (8). This means that if a person weighs 200 lbs, they should try to lose 20 lbs in six months. This is equivalent to approximately 3 lbs/month, or just under 1 lb/week. In order to coax the body into using its fat stores you have to create an energy deficit. An energy deficit means that you are supplying your body with less calories than what it needs to function, so that it uses its stored energy to make up the difference. Theoretically, in order to lose 1 lb of fat, over time you have to create a deficit of 3,500 cal. A daily deficit of 250-500 cal/day will result in ½-1 lb. lost per week. Sometimes the rate of weight loss is slower than the numbers suggest. Any energy deficit created in the body will be met with resistance. Fat is important for survival, and the body does not always readily give it up. Caloric restriction is often met with behavioral and physiological compensatory responses that make it more difficult to lose weight. In other words, when you give your body less energy than it needs, it will automatically decrease its calorie burning and stimulate your hunger drive to compensate for the deficit.

There is no one method of weight loss that works for everybody, however, most experts agree that in order achieve long-term, successful weight loss, three things need to be addressed; diet, physical activity and behavior change.

Figure 9.8 Healthy Weight Management

Diet

When it comes to losing weight, calories are important. As stated earlier, to lose body fat you must have a calorie deficit. However, if you cut back too drastically and your caloric intake is too low, then it will be more difficult to maintain your weight loss efforts. Allowing yourself to become too hungry between meals will, most likely, backfire and cause you to choose higher calorie foods to compensate.

Very low calorie diets will cause rapid weight loss, especially in the first few days. During the initial days of a very low calorie diet, the body uses up its muscle and liver glycogen. A well-nourished adult stores approximately 500 g of glycogen in their body and each gram of glycogen is stored with 3 g of water (1,500 g of water). If most of this is used up during the first days of a diet, that would be equivalent to approximately 5 lb. of weight lost. About 70% of weight loss during the first few days is due to body water and glycogen losses. About 25% comes from body fat stores and 5% from body protein (muscle). This is especially true for low carbohydrate diets, such as a keto diet. Another problem with these types of diets is that most people do not change the underlying habits that contribute to the weight gain in the first place, so most people tend to regain the weight when they “go off the diet” and return to their regular eating habits. These types of diets may also contribute to reduced amounts of lean mass which can cause decreases in basal metabolic rate.

So what is the answer? Ideally, a moderate reduction in caloric intake coupled with an increase in physical activity to create a modest and sustainable deficit. Reducing calories by 250–500 kcal/day while burning more calories through exercise is the best option.

Satiety (fullness) is controlled by the volume of food eaten rather than the number of calories consumed. For example, if you eat bulky, high volume foods, you will become satiated faster, and with less calories, than with high calorie/low volume foods. Fruits, vegetables and whole grains are high volume/low calorie foods due to their fiber content. Foods such as candy, cookies and fats are low volume/high calorie foods. Because of their low volume, you can eat a lot more of these foods (and a lot more calories!) before you feel satisfied. Another trick to make you more satisfied with less food is to include lean protein and some healthy fat with each meal. Fat slows the movement of food out of the stomach and can prolong satiety. Although the exact mechanism is unknown, protein increases satiety more than any other nutrient and, therefore, is beneficial in aiding weight loss.

Weight loss often slows down and plateaus after several weeks of caloric restriction. One of the reasons this occurs is because once weight loss has been achieved, the number of calories the body requires decreases so you need fewer calories to maintain your new weight. If you want to continue to have a deficit, you will need to adjust your caloric intake as you lose weight. Another reason this happens is because the percentage of weight loss due to water is highest at the beginning of a “diet.” After several weeks, the amount of water weight lost is minimal, weight loss continues to occur but at a much slower rate.

Physical Activity

Physical activity can help promote weight loss by increasing calorie burning. In addition, by burning more calories through exercise you do not have to restrict your food intake as severely as if you were trying to lose weight with diet alone. People trying to lose weight, or maintain weight loss, may need to participate 45 min or more of moderate intensity exercise to achieve their goals. Exercise may also replace sedentary activities that tend to be accompanied by eating, such as watching TV or surfing the Internet. When it comes to weight loss, going for a walk and not eating is better than sitting in front of the computer while eating a bag of chips!

Behavior Modification

Diet and exercise can help you lose weight but in order to maintain weight loss you also need to change the habits that cause you to gain weight in the first place. Identifying behaviors that contribute to overeating can help you develop new behaviors that promote a healthy body weight. For example, if you tend to snack in the evenings while watching TV, brushing your teeth after dinner can “signal” the end of the day’s food intake and may keep you from eating more. Changing behaviors is easier if you do it one small step at a time. If you try to change too many things at once, you may be setting yourself up for failure. Keeping a food record is helpful for trying to identify eating patterns and behaviors. Logging what and when you eat along with how you feel and where you are when you eat them can help you identify patterns that may be contributing to weight gain or impeding your weight loss.