Women’s Protein Needs: The Critical Key-Protein and Bone Health
Q: Do women need as much protein as men?
A: It depends on how you want to answer the question: per pound of lean body mass women’s protein needs are the same, but per pound of body mass (weight) a woman’s needs are lower.
Women are generally smaller than men and have less lean body mass than men (on average), so women have fewer pounds of lean body mass per pound of body mass (weight). Both men and women need about 1 gram of protein per pound of lean body mass (2.2g/kg of fat free mass if you want to go metric).
You can use something like the InBody 570 to get an accurate measurement of your lean body mass, or you can use averages: According to the CDC’s NHANES data the average American woman is 40% body-fat and 176.4 pounds. This means she has about 105 pounds of lean body mass. So, the ideal for an “average” American woman would be about 105g per day of protein, and we would encourage you to get at least 80% of the ideal, or 84 grams. Here is more on how much protein you need, and what changes there would be with age or activity levels.
Q: Is a “high” protein diet bad for women’s bones?
A: No. The opposite is true. Protein intake boosts calcium absorption and bone strength.
We’ve all heard the myth that high protein diets are “acidic” and leach calcium from the bones to buffer the “acid” from dietary protein. This sounds logical until you give it any scrutiny.
Here’s a quote from Layman, et al (big review paper on protein intake and osteoporosis):
“The efficacy of calcium and protein are interrelated [3]. Calcium supplements are largely ineffective for remodeling of bone matrix if protein is limiting. Positive effects of calcium appear to require intakes of protein >1.2 g/kg to have beneficial effects. The long-held belief that increased dietary protein could cause bone loss as reflected in increase urinary calcium is incorrect [33], and protein is now recognized to increase intestinal calcium absorption in addition to enhancing bone matrix turnover [34].”
Translation: the old idea that increasing dietary protein causes bone loss is wrong. Calcium supplementation without adequate protein intake does not work. Protein increases how much calcium you absorb, and helps your bones get stronger.
One of the misconceptions about bone is that it’s mostly calcium, but it is actually mostly protein. Bone is 30% protein by weight and 20 to 25% calcium by weight. Calcium is obviously very important, and we also should remember the structural framework of bone is protein.
A few more tidbits on protein and bones:
1. A 6 month study on women with (what I would call) very high protein intakes showed no harmful impact on their bone mineral content or bone mineral density. The intake was 1.27 grams of protein per pound of body weight (not just lean body mass), or 224g per day for the theoretically average women above.
I call that level of protein intake “very high “because it’s a lot higher than makes sense for most women when you consider the trade-offs. There’s no health risks, it’s more the calorie trade offs. 224 grams of protein is about 1,000 calories, and for most women that doesn’t leave much room for eating anything else.
2. A meta-analysis (a study of studies – pooling a lot of data to get a better picture) of people 65+ showed that a “high” protein intake lead to significantly lower risk of hip fractures. (“High” in this study was higher than the USDA’s RDA of 64 grams for the “average” woman above.)
Bottom Line on Women’s protein needs:
Protein is good for you and for your bones. Can you have too much? Yes, in theory. However, in practice it’s pretty hard to do without going over your calorie budget.
Coach Josef Brandenburg — ACE | NASM | Precision Nutrition | Training Peri and Menopausal Women | Pain-Free Performance Specialist Certification | Functional Kettlebell Training | 28 years coaching | Specializes in strength training for women over 40.
Josef Brandenburg, best selling author, is the co-owner and a coach at True 180 Personal Training, Charlotte’s most effective personal training studio for women since 2016. With decades of experience and multiple certifications, he shares his research with you including that on women’s protein needs.