Study: Sugary Drinks Combined with Protein Slow Down Metabolism

Maintaining a high metabolism is important for several reasons. When your metabolism is low, your body burns energy from food more slowly than a person with a high metabolism. And when it takes longer for your body to burn energy, you'll have a harder time losing weight and maintaining a healthy weight; thus, increasing the risk of chronic disease like obesity and diabetes.

According to a new study, however, drinking a sugary beverage with a high-protein meal may lower your metabolism. Researchers from the USDA-Agricultural Research Service Grand Forks Human Nutrition Research Center found that roughly one-third of the calories consumed from sugary beverages were not expanded. Furthermore, researchers found that people who consumed sugary beverages with a high-protein meal experienced reduced fat metabolism and decreased metabolic efficiency, which they believe could lead to increased fat storage.

For the study, researchers recruited 27 men and women, all of whom were a healthy weight. Researchers requested the participants to make two visits, during which they received two 15% protein meals after fasting for the night and two 30% protein meals.

Basically, drinking a sugary beverage with a high-protein meal decreases fat oxidation -- and this, according to the study's researchers -- may contribute to weight gain. More specifically, researchers found that sugary beverages were associated with an 8% decrease in metabolic function. When participants consumed a sugary beverage with a meal consisting of 15% protein, metabolic fat oxidation dropped to 7.2 grams. When participants consumed a sugary beverage with a meal consisting of 30% protein, however, metabolic fat oxidation dropped to 12.6 grams.

"Our findings suggest that having a sugar-sweetened drink with a meal impacts both sides of the energy balance equation. On the intake side, the additional energy from the drink did not make people feel more sated. On the expenditure side, the additional calories were not expended and fat oxidation was reduced. The results provide further insight into the potential role of sugar-sweetened drinks -- the largest single source of sugar in the American diet -- in weight gain and obesity," explained the study's lead author and researcher.

Researchers further stress that this study was performed on participants with a healthy weight. Therefore, the results may be different in individuals who are overweight. This doesn't necessarily mean that you should stop drinking soda with protein-rich meals, as this study was relatively small. Nonetheless, there's no denying the fact that sugary beverages can take a toll on your health in multiple ways.

This study was published in the journal BMC Nutrition.