A High vs Low Protein Intake on Muscle and Fat: Our Study Summary

Whilst studying at the University of South Florida I was fortunate enough to be on the Physique Enhancement Lab research team. Headed up by world leading researcher Dr. Bill Campbell PhD, and alongside fitness-industry titans like Dr. Layne Norton PhD (biolayne.com) and Laurin Conlin M.S. (laurinconlin.com).

This facility is the premiere place for female physique research, and one of the few labs in the world that focuses its scientific research efforts on physique sports, as Dr. Campbell takes a refreshingly-practical approach to his work, and insists on investigating variables that are directly applicable to the 'real-world' of fitness.

This can be seen with our study, titled 'Effects of a high (2.4g/kg) vs low/moderate (1.2g/kg) protein intake on body composition in aspiring female physique athletes engaging in an 8-week resistance training program', since we sought out directly measurable changes in body weight, lean body mass, fat mass and body fat percentage.

We studied seventeen, weight-trained women, aspiring to compete in physique competitions. The 'high protein' group ate at least 2.4g/kg of protein daily, whilst the 'low protein' group ate 1.2g/kg or less. Both groups followed an upper/lower weight training program which had them lifting a total of four times per week, for eight weeks.

In this short space of time, the women in the high protein group were able to add an impressive 2.1kg of lean body mass, and simultaneously lose 1.1kg of fat mass. Whilst the low protein group saw just a 0.7kg increase in lean body mass and a 0.7kg reduction in fat mass (note: these body fat changes were not found to be 'statistically significant').

This spotlights the changes women can make to their body in just eight weeks, when top-quality training and close food tracking are ensured.

Overall, the results show the impressive power of protein. Especially since the high protein group ate on average 423 more daily calories than their low protein counterparts, yet did not gain more body fat... Perhaps asking questions of the traditionally touted view of 'a calorie is a calorie'.


I would love to hear what you think about these findings and field any questions you have about protein intake for optimal gym results. You can leave it in the comments, blow up my Instagram linked below, or take the discussion directly to my email inbox.

Have a cracking day.



Campbell B, Aguilar D, Vargas A, Conlin A, Sanders A, Fink-Irizarry P, Norton L, Perry R, McCallum R, Wynn MR, and Lenton J. Effects of a high (2.4 g/kg) vs. low/moderate (1.2 g/kg) protein intake on body composition in aspiring female physique athletes engaging in an 8-week resistance training program. Presented at the 2016 International Society of Sports Nutrition Annual Conference, Clearwater, Florida, June 2016.


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