Does protein powder make you gain weight?

Does protein powder make you gain weight? We've looked at the science and talked to nutritionists to find the answer

Does protein powder make you gain weight? Image shows woman drinking shake
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Adding a little protein powder to your morning smoothie is a great way to boost your muscle mass. It can also be a healthy way to ensure your body gets the protein it needs to repair muscles after a particularly tough workout, making your recovery times a little quicker. 

However, some people worry that adding protein powder to their routine won't just lead to more muscle but also more weight, even if they're using one of the best protein powders for weight loss. But does protein powder really make you gain weight? 

We'll look at the science to explain how protein powder works in the body and how it affects your body's muscle mass and weight distribution. We'll even offer tips on how to use protein powder so that you can hit your fitness goals without affecting your weight. 

Does protein powder make you gain weight? Here’s what we know

Protein powder alone isn’t likely to cause weight gain, but the way you’re using it might. For example, if you add protein powder to your diet without changing the rest of your meals to accommodate the extra calories, you may start gaining weight. Of course, for some people, weight gain is their goal when they supplement their diet with protein powder, but it’s something to be mindful of if you are trying to lose weight.

One potential source of weight gain when consuming protein shakes may occur when you use them as a meal replacement. Some people do not feel as full after consuming liquids instead of solid food, which may lead to snacking (adding more calories to your daily intake). For example, one study found that whey protein supplements did not result in a measurable increase in fullness or decreased food intake. If you are hungry and need a snack, stick to high-protein foods like Greek yogurt, boiled eggs, or almonds.

Does protein powder make you gain weight? Image shows protein shake and phone

(Image credit: Getty)

Does protein make you gain weight?

First, it's crucial to understand how the body uses protein. Protein is just one of the three macronutrients; the other two are carbohydrates and fat. "Our bodies process these nutrients, and they provide needed energy and nutrition – vitamins and minerals that the body needs to function properly and be healthy," says nutritionist Kimberly Gomer.

When we eat more of these macronutrients than we need, our body converts the extra energy into fat tissue, which is stored in the body for later use. According to Gomer, protein on its own doesn't inherently lead to weight gain — however, if you eat more protein than your body is using, it could result in additional weight.

"Excess protein can result in weight gain if it is consumed in excess of what the body needs," she says. If you're someone who works out a lot, chances are, your body will be able to use more protein than the average person needs to repair and build muscle.

Kimberly Gomer headshiot
Kimberly Gomer

Kimberly is a nutritionist and Director of Nutrition at Body Beautiful Miami, specializing in weight loss and medical nutrition. Alongside her role at Body Beautiful Miami, she is also the Director of Nutrition at the Pritikin Longevity Center. Kimberly has been featured in media outlets, including CNN Health, Women's Health, and Healthline. 

So, eating more protein won't necessarily lead to weight gain – it all depends on how much protein your body can use, which depends on your unique body and your lifestyle. According to Gomer, different types of protein tend to have different effects on the body.

"The body does not recognize a lot of the additives used in the processing of protein," she says. "Our digestive system is not equipped to 'unlock' added preservatives and altered fats used to prolong the life of our food, therefore, we do not fully digest foods preserved in this way. This leads to hunger after eating, increased waste build-up, and greatly increases the workload of the liver."

In other words, processed foods that contain higher levels of protein are far more likely to lead to weight gain indirectly. "In my experience with clients, for instance, protein bars, in particular, can stimulate hunger and not provide the satiety that eating protein in its natural sources like eggs, meat, or beans, for example, would provide," she says. 

"Also, when eating a high-quality protein source, along with a large vegetable portion, that combination provides nutrition and satiety that will contribute to weight loss in a far superior way compared to protein-fortified products."

What are the benefits of taking protein powders?

 Many people assume consuming protein powder is all about building muscle, but it can support several health and fitness goals, including weight loss, getting lean, and muscle repair.

Protein powders might be a good supplement if you are trying to lose weight. A 2017 review found that supplementing with whey protein might reduce body weight and total fat mass in people who are overweight or obese.

High protein intake has been shown to significantly boost metabolism and increase the number of calories you burn. This can amount to 80–100 more calories burned each day. In one study, a high-protein group burned 260 more calories per day than a low-protein group. That’s equivalent to an hour of moderate-intensity exercise per day.

Protein is essential for muscle growth. Many athletes and gym enthusiasts consume protein shakes to support their muscles after strength training, and there is evidence to support this. A 2015 review of studies found that protein supplementation may enhance gains in muscle mass and performance in healthy adults. 

As well as contributing to muscle growth, protein can help repair damaged muscles and tissues. As a result, athletes may use protein powder to speed up recovery from muscle soreness after exercise. Many studies report that taking protein supplements after a workout can aid recovery by reducing muscle damage and improving muscle performance.

Plant-based protein powders may also benefit those who are don’t include animal and dairy protein in their diet. Nutritionist and thyroid health specialist Alice Godfrey said, “It can be difficult for vegans and vegetarians to get enough protein in the diet so protein powders can be really helpful in increasing it.”

Does protein powder make you gain weight? Image shows woman flexing arm muscle

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What are the cons of taking protein powder?

When it comes to protein powders, you might not know exactly what’s inside the tub. As a supplement, the Food and Drug Administration (FDA) leaves it up to manufacturers to evaluate the safety and labeling of products. So, there's no way to know if a protein powder contains what manufacturers claim.

Most protein powders have healthy ingredients, are free of contaminants, and act as nutritional supplements to your diet. However, before you start drinking shakes, consider getting extra protein through a whole food snack or batch cooking meals rather than using shakes as a meal replacement. If you turn to shakes, read nutrition labels carefully and avoid those high in sugar, cholesterol, or saturated fat.

Alice Godfrey said, “I use pure protein powder, for example, those made from pure hemp or pea protein, because you can get protein powders with added ingredients like thickeners, sugars, and sweeteners which are less desirable.”

Some manufacturers add sugars to protein powder to make them more palatable, so look at the label to check the sugar content before adding to your cart. Otherwise, your shake could be adding more than just protein to your day.

Protein powder should be used as a nutritional supplement, not a total meal replacement. If you overuse protein while cutting out other food groups, you may miss out on the nutritional benefits of a healthy, balanced diet.

Does protein powder make you stronger?

Muscle is made primarily of protein; therefore high protein intake can help you gain muscle mass and strength. Protein is essential for muscle growth and a 2018 analysis of 49 studies supports the use of protein supplements for this purpose. In addition, the research suggests that protein supplements significantly improve muscle size and strength in healthy adults who perform resistance exercise training, such as lifting weights.

A study published in the journal Sports Medicine claims that increased protein levels led to enhanced muscle mass and performance when consumed while doing regular strength training. Another study compared two groups of men doing the same workout routine, with one consuming double the protein of the other. At the end of the trial period, the high-protein group had higher muscle mass and performance than the low-protein group.

Looking for more? Check out our feature on muscle recovery after workouts: what to do.  
Alternatively, if you want to give protein powder a go, here’s how to use protein powder to lose weight or gain muscle.  

Catherine Renton

Catherine is a freelance journalist writing across titles such as Verywell Health, Healthline, The Daily Telegraph, Refinery29, Elle, and Vogue. She specializes in content covering health, fitness, wellness, and culture.
A once reluctant runner, Catherine has competed in 30 running events in the past five years and looks forward to one day running the London Marathon.