The next time you sit down to a high-protein meal, you may want to skip the soda or other sugary beverage. And it's not just because their high calorie content is a culprit in overweight, heart and liver disease. When you have sugary beverages along with protein, it interferes with your body's ability to metabolize fat.
Sugary drinks affect the body’s calorie-burning process. Drinking a sugar-sweetened beverage with a meal slows down fat oxidation, the first step in breaking down fat in the body.
The extra calories from sugar-sweetened beverages did not leave people feeling fuller or more satisfied with their meals, and those calories were not all utilized.
The researchers then analyzed how these changes affected the way the participants' bodies burned calories and how nutrients were processed by the body. The amount of carbohydrate, protein and fat used by the participants and the number of calories they burned were also determined.
Drinking a sugar-sweetened beverage with a meal caused an 8 percent decrease in fat oxidation. When the sugary beverage was part of the 15 percent protein meal, fat oxidation was reduced by an average of 7.2 grams. With the 30 percent protein meal, fat oxidation slowed even further — by 12.6 grams.
About a third of the extra calories consumed with the sugary drinks were not used, fat metabolism declined and the body used less energy to metabolize the meals, possibly triggering the body to store more fat, explained Shanon Casperson, lead author of the study, from USDA-Agricultural Research Service Grand Forks Human Nutrition Research Center. The extra calories from sugar-sweetened beverages did not leave people feeling fuller or more satisfied with their meals, and those calories were not all utilized. Both sides of the energy equation were affected for the worse.
“We were surprised by the impact that the sugar-sweetened drinks had on metabolism when they were paired with higher-protein meals. This combination also increased study subjects' desire to eat savory and salty foods for four hours after eating,” said Dr. Casperson, in a statement.