Want to shed those extra pounds? Well, then focus more on what you drink than what you eat, a new study suggests.
Liwei Chen, MD, PhD, Assistant Professor of Epidemiology at the LSU Health Sciences Center New Orleans School of Public Health, is the lead author of study, which has shown that weight gain and obesity are more linked to an increase in liquid calories, particularly sugar-sweetened beverages, than calories from solid food.
For the study, the researchers followed 810 men and women, 25-79 years old, whose 24 hour dietary intake recall was measured by telephone interviews conducted when they entered the study and at 6 and 18 months. Beverages were divided into 7 categories based upon calorie content and nutritional composition.
Each participant's daily nutrient, energy, and beverage intakes were calculated by taking the average of 2 recalls per time point. Liquid calorie intake was calculated as the sum of calories from the 7 beverage categories. Solid calorie intake was calculated by subtracting liquid calories from total calories.
The researchers found that a reduction in liquid calorie intake was significantly associated with weight loss at both 6 months and 18 months.
Their results showed that the weight-loss effect of a reduction in liquid calorie intake was stronger than that of a reduction in solid calorie intake.
The researchers offer a couple of possible explanations for their findings. The absence of chewing when consuming liquids may result in decreased pancreatic responses.
Beverages also clear the stomach sooner than solid food and may induce weaker satiety signals in the gastrointestinal tract.
"Our study supports policy recommendations and public health efforts to reduce the intake of liquid calories, particularly from sugar-sweetened beverages," said Dr. Chen.
The study is published in the May 1, 2009 issue of the American Journal of Clinical Nutrition.