Body fat has the ability to secrete certain hormones throughout the day which can regulate hunger, satiety, and the development of metabolic syndrome. Among the hormones secreted by body fat, leptin and adiponectin are involved in satiety and improving insulin sensitivity, respectively. Both can possibly be modified through altered carbohydrate consumption in order to reduce the risk of metabolic syndrome and type 2 diabetes. By consuming carbohydrates mostly at dinner, one can potentially maximize daytime secretion of adiponectin by eliminating insulin release throughout the day, as well as alter the normal secretion of leptin, resulting in improved insulin sensitivity and greater satiety.
To determine whether a weight loss diet with carbohydrates eaten mostly at dinner would be more beneficial compared to a traditional weight loss diet with carbohydrates eaten throughout the day on improving insulin sensitivity and enhancing satiety. By improving insulin sensitivity one can reduce the risk of diseases associated with metabolic syndrome, including diabetes.
78 relatively healthy police officers (men and women), between the ages of 25 to 55 years, who had BMIs greater than 30kg/m2 (obese). Healthy was defined as being disease free and not pregnant.
The participants were randomly assigned to a weight loss diet with carbohydrates eaten mostly at dinner or a diet with carbohydrates eaten throughout the day. Over the 6 month study period, blood samples were taken periodically in order to measure insulin, adiponectin, and leptin levels and questionnaires about satiety were completed on days 0, 7, 90 and 180.
At the end of the 6 month study period researchers found that the group who ate their carbohydrates mostly at dinner lost more weight, felt fuller, and had greater improvements in insulin sensitivity and blood cholesterol. Simply put, the participants were at lower risk from developing metabolic syndrome than those who consumed a more traditional weight loss diet.
Researchers did not control for physical activity over the course of the study, a factor known to have a profound effect on improving insulin sensitivity.
Eating carbohydrates at night may be a better way to lose weight and improve insulin sensitivity while better adhering to a weight loss diet.
The full article is titled “Greater Weight Loss and Hormonal Changes After 6 Months Diet With Carbohydrates Eaten Mostly at Dinner”. It is in the October, 2011 issue of Obesity (volume 19, issue 10, pages 2006- 2014). The authors are S. Sofer, A. Eliraz, S. Kaplan, H. Voet, G. Fink, T. Kima, and Z. Madar.
Written by Dylan Klein and Marina Vineas, Dept. Nutritional Sciences, Rutgers University-New Brunswick Edited by SA Shapses, PhD, RD