High Protein Diets Safe for Resistance Trained Men

High Protein Diets Shown to Build a Better Body!

The protein debate has been ongoing for years causing confusion with how much we should be including in our diet for optimal fitness. Past studies have implied protein overfeeding causes fat gain and also may increase cancer risk. 

News reports like to grab onto “shock value” leaks of unsubstantiated claims. They conveniently leave out important details like the protein sources lacked quality and were higher in unhealthy fat.

Great information to know about protein and what this article will address is protein intake not being the same for everyone. Researchers have turned their attention to proving the safety and effectiveness of high protein diets for weight lifters.

The Journal of the American College of Nutrition said it best, “at the present time, substantial data indicate that the current recommended protein intake should be adjusted upward for those who are physically active.”

The Proof is in the Protein

Protein and Weight Training
High-Protein Diets Benefit Weight Lifters. Matthew Leete/Getty Images

The Journal of the International Society of Sports Nutrition published an article on high-protein diets. This is the first ever randomized trial conducted on heavily resistance trained males consuming a high-protein diet over several months.

The purpose of the study was to examine the effects of high-protein intake on performance, health and body composition. The participants included twelve healthy men aged mid-to-late twenties with extensive weight training experience (approximately 8 years).

Over a 16-week period split into two 8-week trials, the men ate their normal diet during the first 8-weeks and switched over to a high-protein diet to finish off the program. The additional protein consumed by each participant was obtained from whey protein powder. Total protein intake for each man was greater than 3g/kg of bodyweight.

 A quick metric conversion shows a 200lb man would consume approximately 270g of protein per day during the study trial. This is three times over the recommended daily allowance (RDA) for protein intake.

The participants continued their regular strength and conditioning programs and were required to keep a food journal. Researchers kept extensive clinical records during the study and also included information on blood panels and metabolism per participant.

Protein Positives

High Protein for Weight Training
Weight Training Requires More Protein Intake. Cultura RM/Corey Jenkins/Getty Images

The study was conducted on well-trained men who could probably lift a house. Researchers were not interested in adding more size to their already Hulk-like physiques but set out to show high-protein diets being safe and effective. 

Compared to earlier studies, the current research on high-protein diets didn’t indicate significant effects on body composition, strength or endurance compared to normal protein intake. However, it's necessary to take a look at individual data points.

Discovered during the high-protein phase was 9 out of the 11 participants decreased in fat mass. This finding debunks past claims of protein over-feeding being linked to fat gain. The majority of the men maintained a muscular, lean physique during the trial.

Another positive discovery was no adverse effects on blood lipid panels, kidney or liver functioning. “Thus, it is evident that even at very high protein intakes, there are no harmful side effects.” 

Recommended for future research is examining varying protein intakes on highly trained athletes over a period of years. Specifically to gain “information in terms of whether the highly trained respond more so to a change in training stimulus, diet or a combination of both.” Regardless, science is heading in the right direction with their attention on sports nutrition.


Journal of the International Society of Sports Nutrition, The effects of a high protein diet on indices of health and body composition – a crossover trial in resistance-trained men, Jose Antonio et al., 1/16/16

Journal of the International Society of Sports Nutrition, International Society of Sports Nutrition position stand: protein and exercise, Bill Campbell et al., 9/26/07

British Journal of Nutrition, High dietary protein decreases fat deposition induced by high-fat and high-sucrose diet in rats, Chaumontet C et al., 10/28/15

Journal of the International Society of Sports Nutrition, The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals, Jose Antonio et al., 5/12/14

Journal of the American College of Nutrition, Beyond the zone: protein needs of active individuals, Lemon PW, 10/00

British Journal of Nutrition, Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Dietary protein requirements and adaptive advantages in athletes, Stuart M. Phillips, 10/12

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