Protein is a macronutrient, which in addition to providing energy, also furnishes the body with the necessary building blocks to create and repair new and damaged tissue. High protein diets are typically used to gain muscle and strength, however, these same diets may provide benefits for weight loss.
The Problem with Weight Loss
Creating a calorie deficit is the trick to make weight loss happen. When you burn more energy than you consume, the body uses fat stores to make up for the energy deficit. In the process, body weight decreases.
When the scale tells us we weight less, we assume we’re losing body fat. Unfortunately, the body does not always use body fat stores for energy in calorie deficient states, it can also use muscle tissue for energy.
When most people are on a diet, losing weight is almost a secondary goal. The real goal is improving health or physical appearance. A calorie deficit on its own does not always lead to optimal results. Indiscriminate calorie cutting sometimes causes the body to burn through more muscle than fat leading to less than optimal results.
The ultimate weight loss goal is burning through as much body fat as possible while maintaining as much muscle mass as possible. Research has shown high protein diets may lead to better results.
Research: High Protein Diets & Weight Loss
Study 1: The Effects of High Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review
This study conducted a review of various studies looking into the effects of high protein diets on body weight and fat loss. Researchers found ‘convincing’ evidence exists pointing to increased satiety in high protein diets. They also found ‘some’ evidence showing these diets result in more weight loss and fat loss when compared to diets lower in protein1.
Study 2: Increased Protein Intake Reduces Lean Body Mass Loss during Weight Loss in Athletes
This study looked into the effects of dietary protein on muscle mass during weight loss in athletes. Twenty athletes were broken into two groups. The first was given a diet made up of 15% protein (0.45 grams of protein per pound of body weight), while the second was given a diet made up of 35% protein (1.04 grams per pound). Researchers measured total/lean body weight, fat mass, and performance (on various exercises)2.
Total and lean body mass loss was significantly higher in the low protein group. The study concluded a diet made up of 35% protein (about 1 gram per pound of body weight) was superior in keeping more lean body mass in dieting athletes2.
Study 3: A Moderate-Protein Diet Produces Sustained Weight Loss and Long-Term Changes in Body Composition and Blood Lipids in Obese Adults
This study looked into the short (four month) and long term (12 month) effects of moderate protein diets on body composition in obese adults. Participants were assigned to one of two diets: 1) a “moderate” protein diet of 0.7 grams of protein per pound of body weight & less than 170 grams of carbohydrates per day, or 2) a lower protein/high carbohydrate diet of 0.3 grams of protein per pound & more than 220 grams of carbs per day3.
At the four month mark, both groups lost similar amounts of total weight. The higher protein group lost 22% more fat mass than the lower protein/higher carb group. At the 12 month mark, the higher protein group lost 35% more fat mass than the lower protein group3.
What the Research on High Protein Diets & Weight Loss Says
Research indicates moderate to high protein weight loss strategies are superior at preserving fat free mass (muscle) than lower protein ones. Participants in these studies were placed on diets ranging from 0.7 grams of protein per pound to 1 gram per pound. For example:
- protein intake for a 120 pound individual: 84 grams of protein – 120 grams
- 120 x 0.7 = 84
- 120 x 1 = 120
- protein intake for a 200 pound individual: 140 grams of protein – 200 grams
- 200 x 0.7 = 140
- 200 x 1 = 200
The Bottom Line
When used properly, high protein diets preserve muscle mass during weight loss. Do not use this to justify eating as much protein as possible. Instead, it should be used to build a diet around healthy principles. Replace unhealthy calories such as soda, candy, cookies, and other junk with nuts, seeds, beans, and lean sources of protein.
A calorie deficit (see the calorie calculator) remains a requirement if the ultimate goal is weight loss or a reduction in body fat. Eating too much protein and negating a calorie deficit still leads to weight gain. Simple increasing protein isn’t the best way. Instead, replace other calories (mainly simple carbohydrates/sugars) with protein. This lowers overall calorie consumption while increasing protein intake.
- Halton, T. L., & Hu, F. B. (2004). The Effects of High Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review. Journal of the American College of Nutrition, 23(5), 373-385. doi:10.1080/07315724.2004.10719381
- Mettler, S., & Mitchell, N. (2010). Increased Protein Intake Reduces Lean Body Mass Loss during Weight Loss in Athletes. Medicine & Science in Sports & Exercise, 42(2), 326-337. doi:10.1249/mss.0b013e3181b2ef8e
- Layman, D. K., & Evans, E. M. (2009). A Moderate-Protein Diet Produces Sustained Weight Loss and Long-Term Changes in Body Composition and Blood Lipids in Obese Adults. The Journal of Nutrition, 139(3), 514-521. doi:10.3945/jn.108.099440