Sugary Drinks and Decreased Fat Metabolism: A Possible Link

Sugary Drinks May Reduce the Benefits of Your High-Protein Diet, Study Says


Verywell / Alexandra Shytsman

Are you a healthy eater who tries to build nutritious meals around lean protein? Many people have learned to fill their plates with plant, fish, or lean animal sources of protein in order to reap the rewards that the macronutrient provides: increased satisfaction after eating, decreased cravings for less healthy foods, and an increase in metabolism. But if you drink a sugary beverage with your high-protein meal, you may be shortchanging yourself out of those important bonuses.

Sugary Drinks and Protein-Rich Meals: Study Raises Questions

A small study has shed light on the possible impact of sugary drinks on metabolism and weight gain. The research suggests one more reason to be cautious about consuming sugar-sweetened beverages at mealtime or throughout the day, especially if you build meals around protein to gain health benefits.

In the study, researchers fed 27 young, healthy-weight subjects similar meals that provided 15 percent of calories from protein or 30 percent of calories from protein. With each meal, subjects also drank either a sugar-sweetened beverage (120 calories) or an identical beverage that was artificially sweetened (0 calories). After eating, scientists gathered data about how different macronutrients were metabolized, feelings of fullness, and about food cravings that lingered after eating.

Test subjects who drank a sugary beverage while eating a high-protein meal experienced increased cravings for salty and savory foods. They also felt less full and satisfied even though the sugary drink added more calories to the meal.

And the findings don't end there. Researchers found that less fat is metabolized when you add a sweetened drink to your meal. The decrease in fat metabolism is even greater when the meal is rich in protein. And even though the sugary drink increased caloric intake by 120 calories, only 80 of those calories were burned throughout the day, leaving a 40 calorie surplus. 

On a High-Protein Diet? Think Twice About Your Drink

Even though the scope of the study was limited, it adds fuel to the fire when it comes to concerns about sugary drinks. If you are a healthy eater who follows a higher protein diet, it may give you one more good reason to reconsider your drink choice at mealtime.

Nutrition researchers have long known that creating meals higher in protein helps us to feel satiated. Protein helps us to feel full and satisfied so that we are less likely to eat again shortly after dining. Boosting protein intake can help you to avoid mindless grazing or craving that extra snack.

But these findings suggest that this important benefit may be reduced when you consume a sugary drink with your protein. Dr. Shanon Casperson explains. "With regards to cravings, there was no difference in cravings for sweet foods, but the addition of a sugary drink with the protein meal increased the desire for savory and salty foods." Casperson is a research biologist with the USDA and the lead author of the study. "If you add a sugary drink to your protein meal, your wanting for typical vending machine foods like chips and snacks may actually increase," she says.

And since we already know that consumption of sugary drinks can contribute to weight gain, the unburned soda calories revealed in the study may be meaningful as well because many of us drink far more than 120 calories (about 8 ounces) from sugary drinks each day. "If you were to take those results and apply it to a greater drink consumption, it's not just about 40 calories," says Casperson. "About one-third of the soda calories were not being used."

How to Cut Back on Sugary Drinks

If you are one of those diners who like to fill your glass with sweetened tea, juice, or soda at mealtime, there are dozens of reasons to cut back—especially if you are trying to reach or maintain a healthy weight.

"This study really didn't surprise me regarding weight change and sugar. In fact, this study is consistent with similar studies. Sugar and sugary drinks can add a significant source of calories to the diet and in that way, contribute to weight gain," says Lauri Wright, PhD, RDN, LD. Wright is an assistant professor and director of the doctorate in clinical nutrition program at the University of North Florida and a spokesperson for the Academy of Nutrition and Dietetics. She says that she always recommends clients combine protein with carbohydrates in their meals and snacks, but the quality of the carbohydrate matters.

Added sugars are a prominent and unhealthy source of carbohydrates. "Added sugars account for approximately 16 percent of total energy intake. That’s around 6 tablespoons (91 grams) of added sugar every day. The largest source of added sugars in our diet is from sugar-sweetened drinks." Dr. Casperson wrote in her BioMed Central blog.

So how do you cut back on your intake of sugary beverages? A slow and steady approach is probably best. Wright suggests a few tips that will help you to cut back:

  • Substitute sparkling water for regular soda and you'll get a 39-gram sugar savings.
  • Instead of flavored milk (even vanilla soy milk), try an unsweetened version. You'll benefit from a sugar savings of 6 grams.
  • Unless you are an endurance athlete, skip the sports drinks and choose water flavored with berries, lime or cantaloupe. Save up to 13 grams of sugar.
  • Watch out for the sugar in many of the popular coffee beverages. Have hot tea sweetened with a teaspoon of honey and lemon rather than a vanilla Frappuccino and save 42 grams of sugar!

She also says that it is common to struggle with a dependence on sugar. She suggests getting help from a professional.

It is important that people who want to lose weight have an individualized plan that combines strategies and alters their lifestyle for lasting changes. A registered dietitian can work with a client to identify the most impactful changes needed, offer strategies and promote a sustainable lifestyle that supports health.

A Word From Verywell

Old habits are hard to break. For many of us, the soda habit (or juice habit, or sweetened tea habit) is the daily crutch on which we lean. But researchers continue to find reasons for us to cut back. While this study is small, it adds to the increasing evidence that sodas and other sugary drinks aren't good for us—even when we eat an otherwise healthy diet. Try taking small steps to reduce your intake and see how it impacts your daily life. You might find that you sleep better, feel more energized, or gain other benefits that make the sacrifice worthwhile.

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