New obesity research presented by Temple faculty
Scientists are now predicting that obesity, so prevalent in the United States, is also threatening China and Europe, where an epidemic is expected by 2010. Such warnings make the quest for answers about obesity more pressing than ever.
At Temple’s Center for Obesity Research and Education (CORE), a university-wide, interdisciplinary group of investigators is at the forefront of the field, researching the causes, consequences, treatment and prevention of obesity. Gary Foster, director of CORE and professor of medicine, and Angie Makris, a CORE scientist and assistant professor of medicine, recently presented their findings from several such studies at the Obesity Society’s annual scientific meeting.
Obesity and Heart Health
|Photo courtesy School of Medicine
||Photo courtesy Kelly & Massa
Obesity carries a significant risk to heart health. How do the two most popular types of diets — high-carbohydrate and low-carbohydrate — affect heart disease risk factors in obese men and women?
A national, three-site, National Institutes of Health-funded study, for which Foster is principal investigator, is comparing the conventional high-carbohydrate, low-fat diet with a generic low-carbohydrate diet.
The six-month results from this two-year study suggest that, after both three and six months, low-calorie diets produce significantly more favorable changes in total- and LDL- cholesterol, while low-carbohydrate diets produce significantly greater improvements in HDL-cholesterol and triglycerides. Still, Foster stresses, the longer-term effects of these two diets on cardiovascular disease are not yet completely understood.
“Future studies are needed to see how these diet-related heart health improvements actually affect patients over time,” he said.
Diet and Thinking
Dieting also can affect the mind, or so previous studies suggested. Makris presented findings from an ongoing study that is comparing the effects of low-calorie and low-carbohydrate diets on cognitive function in 47 obese men and women. While earlier studies have suggested that dieting may negatively affect cognitive function, due to preoccupying thoughts about eating and weight, Temple’s researcher found otherwise.
Findings from this study suggest that individuals participating in a six-month behavioral weight loss program do not experience cognitive impairments over time, possibly due to a better sense of control over eating behavior and weight. Furthermore, the study findings suggest that there are no significant differences in cognitive performance in individuals consuming either a low-calorie or low-carbohydrate diet for six months.
Technology and Weight Loss
Makris also shared new research on the value of technology in monitoring and treating obesity and overweight. Consumers and healthcare professionals are increasingly interested in using the Internet, cell phones and personal digital assistants for health purposes. But questions remain about cost and efficacy. This study compared the effects of behavioral weight loss treatment in 72 obese men and women using computerized software to monitor food and activity. Findings from this study suggest that replacing approximately 50 percent of face-to-face dietitian visits with e-mail communication resulted in similar weight loss.
“We found that technology can be used to produce significant improvements in weight and cardiovascular disease risk,” Makris said.
Foster was a contributing author on a study of adolescent weight loss expectations, which was led by Robert Berkowitz of the University of Pennsylvania School of Medicine.
The study compared the weight loss expectations of obese adolescents with those their mothers had for them. It’s known that overweight adults usually want to lose more than the 5 to 10 percent of weight typically lost through most treatment programs. Participants were asked to characterize the weight loss amount needed to reach their “dream,” “happy,” “acceptable” and “disappointed” weights.
To reach their dream weight, the adolescents wanted to lose a significantly greater amount of weight than their mothers expected them to lose. However, both the weight losses desired by adolescents and by their mothers far exceeded what was realistic. (Typically, behavioral weight loss approaches for teens lead to a 4 percent reduction in body mass index, or BMI.) These findings were similar to those previously found in obese adults. The researchers recommend that future studies with adolescents look at the impact of unrealistic expectations on treatment disappointment and drop-out.
Food Restriction and Craving
Makris and Foster were contributing authors on a study of cravings and food restriction led by Corby Martin of Louisiana State University. They found that food cravings and preferences decrease more for foods that are restricted during the first six months of weight loss treatment. This finding supports recent evidence that restriction of foods during dieting does not increase, but actually decreases, cravings. The scientists said that decreased cravings during dieting are a good predictor of weight loss.
CORE continues to study obesity on numerous fronts. Current projects include research focused on sleep apnea and obesity, the safety and efficacy of an implantable gastric stimulator, and the prevention of pediatric diabetes. A particular focus of the center is a greater understanding of the causes, treatment and prevention of obesity among minorities of lower socioeconomic status, among whom obesity is more prevalent.
— Eryn Jelesiewicz