Researchers Conclude: Avoiding Sweetened Drinks May Help Weight Loss

Background The National Center for Health Statistics (NCHS) estimates that 67% of US adults are overweight or obese and that obesity rates have steadily increased since the 1960s. This trend has been accompanied by an increase in mean caloric intake from 2450 to 2693 kcal/d. Because research suggests that beverages account for almost half of this increase, there is considerable interest in understanding the overall effect of beverage intake on obesity trends. For example, some studies suggest a positive association between intake of sugar-sweetened beverages (SSBs) and body weight. Others propose that milk intake may help in weight loss. However, data are inconsistent and sometimes contradictory, likely due to the use of different populations and failure to control for important confounding factors such as physical activity. To study this further, Caballero and colleagues analyzed data collected in a prospective, longitudinal human nutrition trial, and their findings are published in the May 2009 issue of The American Journal of Clinical Nutrition.

Study Design This research was a component of the PREMIER trial, an 18-mo randomized, controlled, behavioral intervention trial originally designed to test the blood-pressure-lowering effects of two multicomponent lifestyle intervention programs in persons at risk for hypertension. Because of this design, patterns in food and beverage consumption were altered from the beginning to the end of the study for many of its participants. The analyses for the present study, however, were conducted by combining all participants and statistically controlling for intervention assignment. At the beginning of the study and 6 and 18 mo later, dietary intake was measured by using two 24-h dietary recalls. Beverages were categorized on the basis of their caloric content and nutritional composition as SSBs (eg, regular soda and fruit “drinks”), diet drinks (eg, diet soda and artificially sweetened juices), milk, 100% juice, coffee and tea with sugar, coffee and tea without sugar, or alcoholic beverages. Weight, height, and physical activity were assessed and controlled for in the statistical analyses.

Results The average age of participants (n = 810) was 50 y; most were non-Hispanic white with at least a college education. Only 5% were classified as normal weight, whereas 65% were considered obese. Baseline mean energy intake from beverages was 356 kcal/d. This declined to 100 kcal/d at the end of the study, and this change was associated with a weight loss of ~0.25 kg (~0.6 lb) at 6 and 18 mo. The reduction in energy intake from beverages was more strongly related to weight loss than was the reduction in energy intake from foods. A reduction in intake of SSBs, but not other beverage types, was significantly associated with weight change.

Conclusions These results provide evidence that SSBs may be especially important contributors to our current obesity epidemic and that a reduction in SSB intake of even 1 serving/d might help with weight loss. This study represents an important contribution to the current literature because it provides the first documentation of the relative effects of calories from beverages compared with those from foods on weight loss in free-living adults.

Lähde: AJCN Research Highlights, May 2009