Consuming Protein Supps With Meals Can Help You Lose Weight (and Gain Muscle)

Man Drinking Protein Shake
 bogdankosanovic / Getty Images

Protein supplements tend to be one of the first things people stock up on at the start of a fitness kick. Whether in the form of protein bars, powders, or ready-to-drink shakes, protein is lauded as one of the best ways to refuel after a workout or snack healthily between meals.

But if you’ve started strength training and supplementing strictly to lose weight, your success may hinge on more than how much protein you’re getting. With protein supplementation, it seems, timing is everything, according to a study review conducted at Purdue University.

It may seem like a no-brainer to swap that midday bag of chips for a protein bar, but snacking on protein supplements between meals may be less friendly to fat loss than supplementing with meals, the review found. In the trials that researchers studied, all study participants who took protein supplements gained lean muscle mass. (That’s good news for your muscles.) The catch? Only 59% of people who supplemented between meals lost fat, compared to 87% of the people who took their supps with meals.

Why the disparity? People who take protein with meals are more likely to actively adjust their calorie intake to compensate for the protein, according to Wayne Campbell, Ph.D., senior author on the study.

“Such dietary compensation is likely missing when protein supplements are consumed as snacks,” Campbell said in a statement. “Calories at meal times may not be adjusted to offset the supplement’s calories, thus leading to a higher calorie intake for that day. If the goal is to manage weight, then snacking on protein supplements may be less effective.”

On the other hand, Campbell noted, “People who are trying to gain weight may consider consuming protein supplements between meals.”

This is the first case analyzing the timing of protein supps, so more rigorous studies need to be done to determine just how much of an effect timing has, says Purdue postdoctoral research associate Joshua Hudson, Ph.D. But if you’re specifically trying to lose weight, watching your overall calorie intake is a safe bet.

Middle-aged men in particular may have an incentive beyond weight management to watch their overall protein intake. Those eating higher-protein diets may be at a slightly higher risk of heart failure than those who eat less protein, according to a new study in the American Heart Association’s journal Circulation: Heart Failure. 

There were 2,441 men involved in the study, and 334 cases of heart failure were diagnosed over an average of 22 years. At the start of the study, the men were asked to keep track of their diets for four days. Compared to those who ate the least protein, men who ate the highest-protein diets were 33% more likely to end up with heart failure, no matter the source of the protein.

Animal protein was associated with a 43% higher risk of heart failure, and dairy protein a 49% higher risk. Plant protein proved to be the most heart-healthy, but was still associated with a 17% higher risk. The only protein sources that weren’t associated with heart failure risk in the study: fish and eggs.

“As many people seem to take the health benefits of high-protein diets for granted, it is important to make clear the possible risks and benefits of these diets,” study author Jyrki Virtanen, Ph.D., said in a press release. “Earlier studies had linked diets high in protein—especially from animal sources—with increased risks of Type 2 diabetes and even death.”

That’s not to say you should go cutting protein out of your diet. This is one of the first studies to look at the relationship between dietary protein and heart failure risk, so more studies need to be done to find out if moderating dietary protein would help prevent heart failure, according to Heli E.K. Virtanen, Ph.D., first author of study.

That said, it wouldn’t hurt to throw a veggie or two onto your plate.

Check out the American Heart Association’s website for its complete diet and lifestyle recommendations.