High Protein Diets
High protein diets are more mainstream than ever. Bodybuilders, powerlifters, and plain gymrats use these diets to increase muscle mass while others see benefits in terms of improved body composition, weight loss, and more efficient dieting.
The Recommended Dietary Allowance (RDA) of protein is only 0.8 grams per kilogram of body weight or approximately 0.36 grams per pound. This typically provides around 10%-20% of daily calorie intake. Research has shown many benefits in increasing protein intake beyond the RDA, especially when combined with physical activity and strength training.
Benefits of High Protein Diets
1. Increased Muscle Mass1
Building muscle is perhaps the most commonly known benefit of a high protein diet. Increasing protein intake on its own does not necessarily lead to more muscle mass. Most studies looking at the muscle building effects of protein have combined high protein diets with an intense strength training routine.
In one study, participants were split between a normal protein group and a high protein group. The normal protein group was given 1.04 grams of protein per pound of body weight per day while the high protein group was given 1.36g/lb. The results showed:
- the high protein group lost 0.22 pounds vs a gain of 2.9 pounds for the normal protein group
- the high protein group lost 3.5 pounds of fat vs a loss of only 0.66 pounds for the normal protein group
- both groups gained 3.3 pounds of fat free mass (muscle)
- the high protein group saw a 2.4% reduction in body fat percentage vs a 0.6% reduction for the normal protein group
The high protein group averaged 2,614 calories per day while the normal protein group only consumed 2,119 calories per day. Despite the higher intake, the high protein group fared better. Both groups engaged in a heavy resistance training program.
2. Reduce Body Fat2
Protein is typically thought of as a weight gaining nutrient. When used correctly, protein also seems to help with reducing body fat. Reducing body fat is contingent on creating a calorie deficit (reducing calorie intake while increasing energy expenditure) and one was to decrease intake is relying on foods which increase satiety or fullness. Eating a meal composed of 25-81% protein significantly increases satiety, and by extension, decreases calorie intake.
3. Weight Loss3
Protein has an extremely important role in weight loss. In one study, researchers examined several studies looking at the long term effects of high protein diets on weight loss. Researchers came to two important conclusions. First, diets containing 0.54-0.73 grams of protein per pound of body weight (25-30 grams of protein per meal) provided improvements in body weight management. These higher protein, calorie restricted diets led to greater total weight and fat mass loss when compared to lower protein diets. Second, researchers concluded high protein diets did a better job of weight maintenance and preventing weight regain.
4. Increased Muscle Mass in the Elderly4
Muscle mass is extremely important to the elderly in order to maintain and improve mobility and quality of life. Just as a protein helps increase muscle in younger individuals, the elderly population sees similar benefits. Sarcopenia is the loss of muscle mass as part of the aging process. It’s estimated that sarcopenia results in a 3-8% reduction in muscle mass per decade beginning at 40-50 years of age. Advanced sarcopenia impacts day to day activities, limits freedom, and decreases quality of life.
The RDA for protein (0.8g/kg/day or 0.36g/lb/day) is seen as inadequate to prevent muscle loss during aging. Recent literature recommends between 0.45-0.68g/lb/day. Unfortunately, around one third of adults over 50 don’t even meet the RDA for protein, which in many cases, is already too low. Older adults should consume slightly more protein than the RDA and aim for taking in 30 grams of protein per meal.
5. Makes Diets More Efficient5
Protein makes diets more efficient. In a review of multiple studies, researchers examined how protein during calorie restricted diets affected athletes. They found body fat percentages and body weight decreased while muscle mass increased. Lowering body fat while increasing muscle simultaneously is the perfect outcome of any weight loss strategy. The athletes that participated in these studies had protein intakes ranging from 1.04g/lb/day to 1.4g/lb/day.
The Bottom Line
High protein diets are beneficial for a wide range of individuals. They increase muscle mass, reduce body fat, and make diets work better. The current RDA for protein is low for certain individuals. Elderly populations see benefits when protein intake is over 0.45 grams per pound while other groups (mainly those engaging in physical activity) may benefit from intakes around 1.4 grams per pound. Protein is only part of a larger strategy to improve overall health. Increasing protein without addressing other underlying issues leads to limited success.
- Antonio, J., & Ellerbroek, A. (2015). A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women – a follow-up investigation. Journal of the International Society of Sports Nutrition, 12(1). doi:10.1186/s12970-015-0100-0
- Pesta, D. H., & Samuel, V. T. (2014). A high-protein diet for reducing body fat: mechanisms and possible caveats. Nutrition & Metabolism, 11(1), 53. doi:10.1186/1743-7075-11-53
- Leidy, Heather J, and Peter M Clifton. (2015). The role of protein in weight loss and maintenance. The American Journal of Clinical Nutrition, 101(6).
- Paddon-Jones, D., & Leidy, H. (2014). Dietary protein and muscle in older persons. Current Opinion in Clinical Nutrition and Metabolic Care, 17(1), 5-11. doi:10.1097/mco.0000000000000011
- Helms, E. R., & Zinn, C. (2014). A Systematic Review of Dietary Protein during Caloric Restriction in Resistance Trained Lean Athletes: A Case for Higher Intakes. International Journal of Sport Nutrition and Exercise Metabolism, 24(2), 127-138. doi:10.1123/ijsnem.2013-0054