Does Protein Make You Gain Weight? How To Use It To Gain Muscle & Lose Fat

Protein is the nutrient of choice when it comes to both muscle growth and fat loss. However, you may wonder, "Does protein make you gain or lose weight?" While protein is often touted for its weight loss benefits, it can also contribute to weight gain by helping your body build and maintain muscle mass.

We spoke with nutrition experts to help answer all your protein and weight gain questions.

Protein is an essential macronutrient that plays a critical role in metabolic health—the ideal levels of blood sugar, triglycerides, cholesterol, blood pressure, and waist circumference—and several other bodily functions1 related to metabolism. Here are a few ways this important nutrient can help you lose fat if that's a goal of yours:

Protein helps you feel satisfied after a meal2, making it less likely you'll overeat or crave snacks throughout the day.

"Eating protein earlier in the day, such as at breakfast, increases satiety," says Don Layman, Ph.D., a professor in the Department of Food Science & Human Nutrition at the University of Illinois at Urbana-Champaign. "The main effects on appetite appear to be reduced snacking between meals and at night."

Protein has an "insulinotropic effect3," which encourages insulin secretion from your pancreas to help clear glucose (sugar) out of your blood.

Gabrielle Lyon, D.O., a functional medicine physician and the founder of the Institute for Muscle-Centric Medicine, tells mindbodygreen, "Protein can stabilize your blood sugar by preventing insulin spikes. Less insulin spiking means more sustained energy levels and fewer hunger pangs throughout the day."

TEF is the amount of energy4 required for your body to digest, absorb, metabolize, and store the food you eat. Protein has a higher thermic effect than carbs and fats since your body has to work harder to break it down and digest it, thus using more energy and burning more calories when consumed.

"Protein is a macronutrient that provides 4 calories per gram. Approximately 20% of calories consumed from protein are lost as heat compared to 5% with carbs," says Layman, so eating more protein while reducing your carb intake is a surefire way to burn more fat.

"When comparing a high-carb, low-protein diet with a high-protein, reduced-carb diet (with subjects eating the same amount of calories), the protein group burned about 300 more calories each day," Layman adds.

Protein can help you lose fat by stimulating MPS, a metabolic process5 that plays a critical role in building and maintaining muscle mass. Research shows that consuming at least 20 grams of high-quality protein6 in three-hour intervals throughout the day is optimal for stimulating MPS and burning fat.

The type of protein you consume affects your weight loss goals. In particular, whey protein (a milk-based protein) has been associated with increased satiety7, healthier body composition8, lower cardiovascular risk factors9, and greater weight loss10 than other protein sources.

High-protein diets have been found to promote gains in muscle mass11 when combined with resistance training, prevent loss of muscle mass12 during calorie restriction, and reduce the natural loss of muscle mass13 that occurs with aging.

If your goal is to gain lean muscle, pair your protein with healthy carbohydrates. Complex carbs in fruits, vegetables, whole grains, and legumes give you the energy required for strenuous exercise, while protein helps repair and build muscle. Essentially, your body won't have the energy to allow protein to do its job without sufficient carb intake. Also, combining these two macronutrients helps stabilize blood sugar14 when consumed simultaneously. 

However, if you're trying to lose weight and burn fat, you'll want to increase your protein intake15 while reducing carbs. Conventional diets are generally low in fat and have a macronutrient breakdown16 of roughly 50% carbs, 20% protein, and 30% fats. For weight loss, these ranges should be adjusted to 10 to 30% carbs, 40 to 50% protein, and 30 to 40% fats.

If you regularly engage in resistance training, increasing your daily protein intake17 can boost overall lean body mass and lower-body muscle strength.

Protein is comprised of 20 amino acids18 (the building blocks of protein). Nine are essential, meaning your body doesn't produce them and needs to acquire them through diet. The amino acid leucine plays a significant role in muscle development19. Leucine is one of three branched-chain amino acids (BCAAs)—the other two being valine and isoleucine—which are broken down in muscle tissue20 instead of the liver like other essential amino acids.

"When you eat high-quality protein that contains adequate amounts of leucine (around 2.5 grams), you turn on your body's calorie-burning, muscle-building process for five to six hours," says Lyon.

Currently, the recommended dietary allowance (RDA) for protein is 0.8 gram per kilogram of body weight21 (g/kg/bw), regardless of your age, gender, weight, and activity level. However, if you're an active person looking to gain muscle or lose fat, you'll need more protein than the conservative RDA to reach your fitness goals.

There's no one-size-fits-all approach to protein intake. That's because the amount you need depends on several factors, including age, weight, and activity level. However, the American College of Sports Medicine (ACSM) recommends that athletes and active individuals up their daily protein intake to between 1.2 and 2.0 g/kg/bw22. For many people, that's more than 120 grams of protein per day.

"Low protein intake halts muscle gain, but high-protein intake doesn't 'cause' muscle gain," adds Layman. "You can enhance muscle protein synthesis with protein intakes of 1.2 to 1.8 g/kg/bw. Many athletes will reach 2.2 g/kg/bw (1 gram per pound)."

Similar to your daily protein needs, the "safe" amount of protein you can consume depends on your individual needs. An average healthy adult can generally eat up to 2.0 g/kg/bw daily and not experience side effects. However, chronic protein consumption of over 2.0 g/kg of body weight daily23 could potentially cause health issues in some people, such as:

If you have kidney health issues such as chronic kidney disease (CKD), you must be careful with your protein intake24 since excess protein can cause waste to build up in your blood and your kidneys may be unable to remove all the extra waste. "For chronic kidney disease patients unable to regulate protein metabolism and fluid balance in the body, too much protein can be harmful," cautions Lyon.

In no particular order, here's a list of high-quality protein sources to include more of in your diet to gain muscle and lose fat: 

Research suggests that consuming protein within your anabolic window31 (30 minutes to two hours after a workout) enhances muscle repair and growth.

To optimize MPS, aim to consume 25 to 30 grams of high-quality protein21 during two or three meals throughout the day. This amount has been found sufficient for both younger and healthy older adults.

"In general, the first meal of the day after a nighttime fasting period is the most important for MPS," says Layman. "However, if you're eating a low protein diet (only 50 to 60 grams per day), getting at least one meal up around 40 grams is critical. If you have a higher protein intake (around 100 grams per day), it's best to distribute the protein. The first and last meals will greatly benefit muscle growth."

"Eating a high-protein meal every four to six hours during feeding windows will maintain your body in an anabolic state with ongoing muscle protein synthesis," Lyon explains. "The first and last meals of the day are most important because they're when you break your overnight fasting period and prepare your body for sleep, where you do most of your repair and regenerate activities."

Protein is a powerful macronutrient that plays a critical role in several metabolic functions, including muscle growth and healthy weight management. Eating a wide variety of high-quality protein sources (like those in some of these high-protein breakfast recipes) can help you reach your health and fitness goals. Talk to your doctor or a registered dietitian if you want to learn more or have further questions about your protein intake.