It can make you crave junk food hours later, too.
In the study, researchers recruited 27 healthy adults for two laboratory visits: In one visit, they ate two, 500-calorie meals made up of 15 percent protein, one with a sugar-sweetened beverage and the other with a drink made with artificial sweetener.
In the other visit, they ate two 500-calorie meals made up of 30 percent protein, again with a sugary drink for one and an artificially sweetened drink with the other.
The researchers discovered that drinking a sugar-sweetened beverage significantly reduced diet-induced thermogenesis, or the amount of energy it takes to metabolize meals, and fat oxidation, a process which kick-starts the breakdown of fat molecules.
And the more protein they ate, the more their fat oxidation decreased.
When the participants ate the meal with 15 percent protein and drank the sugary drink, their fat oxidation decreased by 7.2 grams, compared to 12.6 grams when they ate the 30 percent protein meal with the sugar-sweetened drink.
“This decreased metabolic efficiency may ‘prime’ the body to store more fat,” study author Shanon Casperson, Ph.D., said in a statement. (To burn fat fast, try the dumbbell fat destroyer.)
Another problem: The added calories with a sugary beverage didn’t help the participants feel any less hungry later on.
And while adding more protein helped decrease cravings for savory, salty, and fatty foods, combining a sugar-sweetened beverage with the protein-rich meal actually increased the people’s desire for salty and fatty stuff later.
Bottom line: Adding more protein to your diet is one of the nine weight-loss rules that work, since it increases satiety and makes you feel more satisfied. (For an actionable eating plan that will help you drop extra pounds, check out The Metashred Diet from Men’s Health.)
But this study suggests adding sugary drinks can take away from those benefits.
That means you if you want to reap the high-protein rewards, you may want to stick with a nice glass of water with your meal instead—especially since artificial sweeteners might actually be giving you a gut, as we recently reported.