How Much Protein is Enough?

Disclaimer: This blog post originally appeared on Dr. Stacy Sims' website and is shared here with her full permission. If you enjoyed this post, we encourage you to explore more of her work by visiting her website.

It’s a question I’m asked by women a lot: How much protein should I consume every day? And while the detailed answer will always depend on your age, your activity level, your menstrual cycle status, and plenty more, there are a few simple guidelines that can help get you on the right side of the protein tracks.

Protein RDA

The recommended daily allowance (RDA) for protein is about 1 gram per kilogram (kg) of body weight, or roughly 0.45 grams per pound (lb). This amount is just about sufficient for sedentary individuals, but it can differ based on age, sex, and activity levels. For active women, sports scientists suggest aiming for 1 gram of protein per pound of body weight.

Research has shown that for women aged 20-35, optimal daily protein intake is 1.6-2.2g/kg/day (0.7g-1g/lb/day), while older women, especially those in perimenopause and menopause, may need slightly higher amounts. This 2023 study recommends that daily protein intake should fall within 1.4-2.2g/kg/day (0.6g-1g/lb/day), with protein distributed evenly across meals every 3-4 hours. This helps maintain lean body mass and supports body composition and weight loss. Studies have also shown that overall daily protein needs are higher during the luteal phase of the menstrual cycle.

Protein Needs in Perimenopause and Beyond

For perimenopausal and menopausal women, daily protein needs increase to about 2-2.3g per kg of body weight (~1-1.2g per lb). As we age, our bodies become more resistant to the muscle-building effects of protein and exercise, requiring higher doses of both. 

This study found that after eating, older women experienced a smaller increase in muscle protein synthesis (MPS), with some studies showing a drop of up to 40% compared to younger women, even when they consumed the same amount of essential amino acids (EAA). This reduced response was also seen after resistance exercise (strength training). 

This research also showed how, to achieve the same training responses, an older woman may require a greater quantity of protein to achieve the same result (~0.4g of protein per kg versus ~0.24g of protein per kg for the younger woman).

Let’s give that some real-world context: If we have two women who weigh the same (let’s say 70kg/~150lbs), but one is in her late 40s and the other is in her late 20s, the 40-something would need to consume 28g of protein post-workout to achieve the same training response as her younger counterpart, who would see the same benefits from consuming ~17g of protein. 

This clearly helps to explain why older women may need more protein to support muscle retention and overall health. Research has found that higher protein intake helps preserve lean body mass and promotes fat loss, especially when combined with resistance training.

This 2020 study in the British Journal of Nutrition found that women on a high-protein diet had higher lean body mass and lower fat mass compared to those on a standard-protein diet. Similarly, a 2015 study in the Journal of the International Society of Sports Nutrition showed that high-protein diets combined with heavy resistance training led to greater reductions in fat mass and body fat percentage.

The Importance of Protein for Health

Adequate protein intake is essential for many aspects of health beyond just muscle maintenance. Protein supports bone health, brain function, and nerve conduction. Inadequate protein can lead to issues like cognitive decline, osteopenia, and sarcopenia (loss of muscle mass and strength) as we age.

Protein Supplementation

While whole foods should be the primary source of protein, supplementation can be helpful, especially for those struggling to meet their daily protein needs. This 2024 meta-analysis found that protein supplementation isn’t necessary for everyone but can be useful for meeting daily protein requirements when whole foods fall short. Whey protein powder is a popular choice, and unflavored protein isolate is my favorite. I use it daily—check out my protein coffee recipe, which is my go-to for early morning workouts!

If you’re interested in learning more on this topic, you might enjoy my Microlearning course on protein supplementation. If you find it difficult to consume enough protein, consider gradually increasing your intake over a few weeks. As a general rule, aim for 30-40g of protein at each meal, plus 15-20g in snacks. Protein timing is a huge topic that I’ll dedicate another newsletter to in the near future.