A High Protein Diet Has No Harmful Effects: A One-Year Crossover Study in Resistance-Trained Males

Abstract

The purpose of this investigation was to determine the effects of a high protein diet over a one-year period. Fourteen healthy resistance-trained men completed the study (mean ± SD; age 26.3 ± 3.9 yr; height 178.5 ± 8.4 cm; and average years of training 8.9 ± 3.4 yr). In a randomized crossover design, subjects consumed their habitual or normal diet for 2 months and 4 months and alternated that with a higher protein diet (>3 g/kg/d) for 2 months and 4 months. Thus, on average, each subject was on their normal diet for 6 months and a higher protein diet for 6 months. Body composition was assessed via the Bod Pod®. Each subject provided approximately 100–168 daily dietary self-reports. During the subjects' normal eating phase, they consumed (mean ± SD) 29.94 ± 5.65 kcals/kg/day and 2.51 ± 0.69 g/kg/day of protein. This significantly increased (p < 0.05) during the high protein phase to 34.37 ± 5.88 kcals/kg/day and 3.32 ± 0.87 g/kg/day of protein. Our investigation discovered that, in resistance-trained men that consumed a high protein diet (~2.51–3.32 g/kg/d) for one year, there were no harmful effects on measures of blood lipids as well as liver and kidney function. In addition, despite the total increase in energy intake during the high protein phase, subjects did not experience an increase in fat mass.

Effects of Whey, Soy or Leucine Supplementation with 12 Weeks of Resistance Training on Strength, Body Composition, and Skeletal Muscle and Adipose Tissue Histological Attributes in College-Aged Males

“…On each occasion, participants were given detailed written and verbal instructions on completing the food logs. Dietary intake data were analyzed using the open-sourced software myfitnesspal (MyFitnessPal, Inc., San Francisco, CA, USA), which has been employed to analyze food intake data in other studies [ 42 , 43 , 44 , 45 , 46 , 47 , 48 ].…”

Protein Recommendations for Weight Loss in Elite Athletes: A Focus on Body Composition and Performance

“…Common concerns regarding the consumption of high-protein diets are the effects of elevated protein on kidney function and bone health, and the lack of scientific evidence to support these claims has been discussed in more detail in the following review articles (Phillips, 2017;Phillips et al, 2016). Put briefly, consumption of higher protein diets does not have detrimental effects on health, including kidney function (Longland et al, 2016), bone health (Shams-White et al, 2017), or liver function and blood lipids (Antonio et al, 2016a(Antonio et al, , 2016b.…”

Effects of 12-Week Low or Moderate Dietary Acid Intake on Acid–Base Status and Kidney Function at Rest and during Submaximal Cycling

“…A recent paper by Møller et al [ 21 ] reported no association between ahigher protein intake and decreased kidney function in pre-diabetic older adults during a one-year intervention. In a study by Antonio et al [ 22 ], high protein intake (2.5 g/kg/day) was compared to higher intake (~3.3 g/kg/day), and it was reported that these high protein diets were not deleterious for kidney function over a one-year crossover study period. However, in the present study, protein intake did not differ between the diet groups, suggesting that not only the protein intake, but also the dietary acid load, should be considered as factors that may affect renal function.…”