WEIGHT LOSS IN GERIATRIC

Weight loss improves many of the adverse health outcomes associated with obesity, including preventing or delaying the onset of diabetes, improving blood sugar control in those with diabetes, reducing low-density lipoprotein (bad cholesterol), raising high-density lipoprotein (good cholesterol), improving hypertension, improving symptoms of osteoarthritis, and providing an improved sense of well-being. Individuals must only lose a small percentage of their weight (B5–10%) to begin seeing these improved health outcomes. As many people know from their personal experiences, weight loss is difficult and lost weight is often regained for a variety of reasons. Returning to the original concept of energy balance, the formula for weight loss is predictable. To lose weight, energy expenditure must be greater than energy consumption.

The first recommendation therefore is lifestyle modification with a combination of increased exercise and decreased intake (diet modification). The amount of exercise needed to lose weight is variable. Current recommendations from the US Surgeon General is for adults to engage in an activity of moderate intensity (such as brisk walking) for 30 min daily or more strenuous activities (such as jogging) for 15–20 min daily. Additional exercise will increase energy expenditure and may result in further favorable health outcomes. Caloric restriction through dieting is also essential for losing weight. The ideal diet has not yet been established, but the principle of reducing caloric intake along with ease of long-term compliance remains the cornerstone of any diet. The American Dietetic Association currently changes their recommendation periodically in an effort to determine the most helpful, practical diet, based on current data. The problem with short-term dieting is that weight loss can rarely be maintained once the diet has ended. Exercise may help maintain some of the weight loss.

Some medications exist for weight loss. These medications are moderately effective, although they often have side effects that limit their widespread use. The history of diet medications has been plagued with adverse health outcomes, including valvular heart disease and heart arrhythmias. Many of these medications have focused on increasing the metabolic rate or suppressing appetite. One such medication that has been approved for use in the United States for weight loss is orlistat. This medication uses a novel mechanism to prevent the body from digesting a portion of the fat that has been ingested, thereby lowering the number of 280 Obesity calories absorbed. The undigested fat is excreted out of the body via bowel movements. This medication has minimal systemic side effects since there is little absorption; however, it results in uncomfortable changes in bowel movements such as oily discharge and increased frequency of bowel movements. Another medication available for weight reduction is sibutramine. The mechanism of action is inhibition of norepinephrine, dopamine, and serotonin reuptake, resulting in weight loss from appetite suppression, possibly combined with an increase in thermogenesis from stimulation of adipose tissue. Use of this medication combined with diet and exercise results in modest reduction (B7%) in weight at 1 year, although sustained weight loss at 2 years is less robust. Because of the high failure rates of lifestyle modification and medical therapies, surgical approaches for weight loss are becoming widely available. The most successful of these surgeries is the gastric bypass. It works by decreasing the size of the stomach, to achieve satiety earlier, as well as by bypassing part of the small intestine, which results in fewer calories being absorbed. This surgery is very effective in achieving weight loss and improving many of the obesity-related diseases. Complications include nutritional deficiencies, postoperative wound infections, leaks at the surgical sites, and postoperative mortality (B1.5%). Due to these risks, this therapy should be reserved for patients who are morbidly obese (BMI 440 or BMI 435), who have obesityrelated diseases, and who have failed behavioral modification therapies.