Following a TBI some persons develop “true hyperphagia” (uncontrollable increase in eating) due to a lesion of the ventro-medial hypothalamus or brain stem. In most cases, however, obesity is due to problems with behavior or mood or both. Impulsiveness and disinhibition lead to indiscriminate overeating. Depression, apathy, reduced motivation or fatigue, lead to inactivity, which also produces weight gain. It is quite common for persons who have suffered a TBI to put on 25-35 extra pounds of fat. Extra fat and physical inactivity are associated with increased risk of high blood pressure, coronary artery disease, heart attacks, stroke, diabetes, colon cancer, gout and arthritis.
Obesity from eating high-fat fast foods and not exercising must be a matter of concern for the patient, his family and his doctors, especially if the patient is smoking cigarettes or has other risk factors for circulatory disease. Obesity can contribute to depression by creating a poor self image and by limiting exercise which decreases blood circulation and lowers endorphin levels in the brain. It is harder for persons with a TBI to lose weight on their own due to problems with apathy, poor memory and executive function disorder (disorganization).
There are no shortcuts to overcoming obesity. In the late 1990s the makers of mass, packaged snack foods (like chips, crackers and cookies) got FDA approval to insert “fat trapper” chemicals in their products. Their advertising says eat all you want, because these chemicals combine with dietary fats, trap them and cause them to be excreted whole without being broken down and released into the bloodstream. Unfortunately these food additives have side effects (like flatulence and rectal “leakage”).
The popular chitosan supplements sold at health food stores as fat trappers appear not to work. In March 2001 a team of nutrition researchers led by Judith Davis at UC Davis in California released a study showing that fat content in the feces of men taking chitosan supplements and of men not taking them was identical over an extended period. Questions about fat trappers should be submitted to the obesity task force of the National Institute of Health in Bethesda, Md.
Health experts recommend the use of a structured weight loss and exercise program with external reminders and re-enforcement. Any such program should be customized to the individual’s needs, based upon analysis of the cause of the problem (cognitive, behavioral, mood), the level of participation and degree of health risk. The medical literature on management of obesity associated with a TBI is relatively new, because it has taken a long time for doctors to recognize this problem and develop a clinical interest in it.
New research has tied obesity with an increased risk of Alzheimer’s Disease (AD), especially in people with the common genetic mutation known as the apoe-e4 gene. Anyone with that gene is now believed to be at 7-10 times the normal risk of developing AD solely as a result of having suffered a TBI. If the same person is also consuming a high fat diet, deficient in fruits and vegetables, and is smoking or not exercising, they are running a dangerously high combination risk of getting AD.