- Aug 14, 2018
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The short answer: per kilogram of body weight, the protein targets that maximize muscle growth look essentially the same for women as for men. The honest complication is that most of the research establishing those numbers was done on men — so here's what the evidence says, where the gaps are, and why the bigger real-world issue for women lifters is usually eating too little protein in total, not choosing the wrong target.
The anchor finding in this field is Morton and colleagues' 2018 meta-analysis in the British Journal of Sports Medicine, which pooled dozens of protein-and-training studies and found muscle gains levelled off around 1.6 grams of protein per kilogram of body weight per day, with the upper confidence bound near 2.2 g/kg. The position stand of the International Society of Sports Nutrition lands in a similar range for building and maintaining muscle. Almost none of the pooled trials were women-only, though, and researchers like Stuart Phillips — whose lab produced much of this work — have been fairly open that female data is thinner than it should be.
What women-specific research exists is reassuring in direction. Studies measuring muscle protein synthesis in women show the same fundamental response to protein feeding and training, and nitrogen-balance and training studies in female athletes haven't produced a different optimal range — when targets are scaled to body weight or lean mass, the sexes land in the same place. There are nuances worth knowing: some research suggests women's muscles may be slightly less sensitive to amino acid feeding at rest in certain hormonal states, and older women of both sexes show "anabolic resistance" that argues for the higher end of the range and solid per-meal doses. None of it changes the headline number much.
Where women lifters most often lose out is the total: dieting culture pushes protein down exactly when training pushes needs up, and during a calorie deficit the research supports the higher end of the range — around 2.2 g/kg or a bit more relative to lean mass — to protect muscle while fat comes off. Hitting roughly 1.6–2.2 g/kg/day, spread over three or four meals with a real protein source at each, covers essentially everything the evidence supports, for women and men alike.
This is a genuinely welcoming place to ask the beginner questions, by the way — anonymously, no judgment. Half the women who find this forum were told for years that lifting makes you "bulky" and protein is a guy thing. The research never said that.
Ladies who lift: what protein target do you actually run, and did raising it change your results? And for everyone — what's your most reliable way of hitting the number on busy days?
The anchor finding in this field is Morton and colleagues' 2018 meta-analysis in the British Journal of Sports Medicine, which pooled dozens of protein-and-training studies and found muscle gains levelled off around 1.6 grams of protein per kilogram of body weight per day, with the upper confidence bound near 2.2 g/kg. The position stand of the International Society of Sports Nutrition lands in a similar range for building and maintaining muscle. Almost none of the pooled trials were women-only, though, and researchers like Stuart Phillips — whose lab produced much of this work — have been fairly open that female data is thinner than it should be.
What women-specific research exists is reassuring in direction. Studies measuring muscle protein synthesis in women show the same fundamental response to protein feeding and training, and nitrogen-balance and training studies in female athletes haven't produced a different optimal range — when targets are scaled to body weight or lean mass, the sexes land in the same place. There are nuances worth knowing: some research suggests women's muscles may be slightly less sensitive to amino acid feeding at rest in certain hormonal states, and older women of both sexes show "anabolic resistance" that argues for the higher end of the range and solid per-meal doses. None of it changes the headline number much.
Where women lifters most often lose out is the total: dieting culture pushes protein down exactly when training pushes needs up, and during a calorie deficit the research supports the higher end of the range — around 2.2 g/kg or a bit more relative to lean mass — to protect muscle while fat comes off. Hitting roughly 1.6–2.2 g/kg/day, spread over three or four meals with a real protein source at each, covers essentially everything the evidence supports, for women and men alike.
This is a genuinely welcoming place to ask the beginner questions, by the way — anonymously, no judgment. Half the women who find this forum were told for years that lifting makes you "bulky" and protein is a guy thing. The research never said that.
Ladies who lift: what protein target do you actually run, and did raising it change your results? And for everyone — what's your most reliable way of hitting the number on busy days?