How Protein Powder Can Assist With Weight Loss, From Body Composition Experts

These days, protein powder is synonymous with gym gains and increasing muscle mass. However, mixing protein powder into your shakes and smoothies can assist with weight loss too.

If weight loss is your goal, squeezing extra protein into your diet might be beneficial. That's because a higher protein diet can increase feelings of fullness, which can help prevent overeating, according to Rachel Adamkowski, MPH, R.D., a sports dietitian and assistant director of football nutrition for the University of Florida.

Research also suggests that protein could alter levels of certain hormones1 in the body that control hunger and appetite, which may translate to decreased food intake.

Stacy Sims, MSC, Ph.D., an exercise physiologist who specializes in nutrition science for women, tells mindbodygreen that increasing your intake of protein could also improve your body composition by reducing fat mass while preserving lean body mass2. "With higher protein intake, even if [your] calorie intake is too low, the circulating amino acids stimulate the brain to keep and build lean mass," she explains, noting that this can lead to the breakdown of fat.

Plus, Sims says that protein can also boost your energy expenditure3, or the number of calories you burn each day at rest, which is partly because protein requires more energy to digest than carbs or fat. "Protein intake [also] prevents a decrease in fat-free mass, which helps maintain resting energy expenditure despite weight loss," notes Sims.

Of course, loading your plate with plenty of protein isn't a sure-fire solution for weight loss. This is because there are lots of other factors at play, including how much you're eating and moving and what the rest of your diet looks like.

While it shouldn't be used to replace other protein-rich foods in your diet, protein powder can be a convenient way to rev up protein intake, notes Mike T. Nelson, CSCS, CISSN, MSME, Ph.D., a human performance specialist.

Nelson says that using protein powder can also make it easier to stick to a high-protein diet, leading to greater results in the long run. Plus, Adamkowski tells mindbodygreen that adding a scoop of protein powder to foods you already eat can help create more balanced meals and snacks, especially if you're having a hard time meeting your protein needs through food sources alone.

Protein powder can also be a great choice after an intense sweat session. "Protein powder can be helpful for getting protein to your muscles after a workout to begin to repair and rebuild6, especially if it will be over an hour until your next meal," says Adamkowski.

Of course, keep in mind that not all protein powders are created equal. In fact, many on the market are pumped full of added sugar or other additives that can sneak in extra calories, which can hinder your weight loss efforts. Similarly, going overboard on the high-fat or sugary add-ins when whipping up your protein shake can drive up the total calorie content, contributing to weight gain.

Derived from a type of protein found in milk, whey protein is one of the most popular and extensively researched varieties of protein powder available. It has also been shown to promote weight loss in several studies. For example, one small study found that whey protein could decrease appetite7, increase levels of satiety-boosting peptides, and enhance blood sugar control in young women. Another study showed that whey had a greater impact on satiety and fullness8 than casein, another type of protein found in milk.

Pea protein is frequently featured in many plant-based protein powders and ranks just after whey in terms of its bioavailability and content of leucine (an essential amino acid involved in muscle growth), according to Sims. Interestingly, a 2023 study comparing the effects of different types of protein powder found that pea protein had a greater effect on appetite10 and satiety than soy protein, another popular plant-based option. 

Casein makes up about 80% of the protein in cow's milk and is digested more slowly than whey, making it a popular choice to provide a steady stream of amino acids to your body throughout the day. Compared to whey, casein could be more satiating in the long run12, which might give it an edge when it comes to weight loss.

With so many different choices available, stepping into the supplement aisle can feel overwhelming. It doesn't help that protein powders are also often paired with other supplements, such as creatine, L-carnitine, or caffeine.

Although adding a scoop of protein powder here and there might seem like a simple way to shed a few pounds, many argue that it probably shouldn't be a mainstay in your meal plan.

According to Sims, sticking to a "food first" approach is best, as protein-rich foods provide a variety of other important nutrients, such as fiber. This can help support a diverse gut microbiome, which is critical for weight loss14. High-protein foods can also provide other nutrients needed to maintain overall health, including vitamins and minerals.

Additionally, keep in mind that protein is just one piece of the puzzle, regardless of whether it's coming from foods or supplements. While upping your intake can be a useful tool to promote weight loss, there's a good chance it won't have much of an impact if you're not making any other changes to your diet or lifestyle, like doing more resistance training.

There is strong research to show that increasing your protein intake can help you lose weight while retaining all-important muscle2. Protein powder supplements make it easy to reach your protein needs (likely over 100 grams a day) if you're low on time or energy.

The more straightforward your protein powder, the better. As Nelson notes, most protein supplements aimed specifically at weight loss aren't super effective, and research often focuses on their short-term effects. While some of these ingredients might offer some small benefits, your results can also vary quite a bit depending on how you're using them, the dosage, and your specific goals.

Instead, we recommend sticking with a protein powder that is low on additives and third-party tested. The content of protein powder is also important. Look for ones that have at least 2.5 grams of leucine per serving to engage muscle growth.

While protein powder is generally considered safe and healthy, it's a good idea to check the label carefully and steer clear of any funky additives or ingredients if you're pregnant or breastfeeding. Additionally, note that a high-protein diet is not typically recommended for people with certain health conditions, such as chronic kidney disease.