Protein needs increase after 50. Most women are eating well below the threshold that supports muscle maintenance – let alone muscle building.
The general recommendation of 0.8 grams of protein per kilogram of body weight per day is a minimum to prevent deficiency in sedentary adults. For women over 50 who are training – and for those who want to be – the research consistently supports a target of 1.2 to 1.6 grams per kilogram per day. Some evidence supports going higher, up to 2.0 grams per kilogram, particularly for women returning to training after a long break.
For a 140-pound woman, the difference is significant: the general recommendation works out to about 51 grams per day. The training-appropriate target is 76 to 102 grams. Most women are eating somewhere in the 50 to 70 gram range. The gap between what they’re eating and what they need is often 30 to 40 grams per day.
Why Needs Increase After 50
The mechanism is called anabolic resistance. Older muscle tissue is less sensitive to the muscle-building signal that protein – specifically the amino acid leucine – triggers. To get the same muscle protein synthesis response, older adults need a higher dose of protein per meal.
In younger adults, approximately 20 grams of high-quality protein per meal is sufficient to maximize muscle protein synthesis. For women over 50, the threshold is closer to 30 to 40 grams. The meal that used to be enough no longer sends the same signal.
The Leucine Threshold
Leucine is the branched-chain amino acid that directly stimulates muscle protein synthesis via the mTOR signaling pathway. Each meal needs to contain approximately 2.5 to 3 grams of leucine to trigger a meaningful anabolic response.
Protein distribution across the day matters, not just total daily intake. Eating 100 grams of protein in one meal produces less muscle protein synthesis than spreading the same amount across three to four meals with adequate leucine in each.
High-leucine sources include eggs (~0.5g per egg), chicken breast (~2.5g per 100g), whey protein (~1.5g per 25g scoop), Greek yogurt (~0.3g per 100g), and salmon (~1.5g per 100g). Hitting 30 to 40 grams of protein per meal from these sources gets you to the leucine threshold reliably.
Why Most Women Under-Eat Protein
Three factors are usually responsible.
Caloric density. High-protein foods don’t fill a plate the way carbohydrates do. Getting to 30 grams of protein per meal requires deliberate planning, not just eating normally.
Reduced appetite. Older adults often report lower appetite overall, which typically leads to reducing food volume – and protein is often the first thing that gets cut when someone is eating less.
The kidney concern. The persistent belief that high protein intake is hard on the kidneys is not supported by the evidence in healthy older adults. In the absence of pre-existing kidney disease, protein intakes in the range of 1.2 to 2.0 grams per kilogram per day do not impair renal function.
A Practical Target
For a woman training twice per week who weighs 150 pounds: aim for 100 to 120 grams of protein per day, spread across three to four eating occasions with at least 30 grams per meal.
That’s a specific, achievable target. Getting there consistently is one of the most reliable things you can do to support the muscle-building response to strength training – and one of the most commonly overlooked.
→ Muscle Loss After 50: What’s Happening and What to Do About It
→ Muscle and Metabolism After 50: The Connection Most Programs Miss
– Stephen Holt, CSCS
29 Again Custom Fitness | Timonium, MD
Nerd Note: Older adults demonstrate anabolic resistance, requiring higher per-meal protein doses to maximally stimulate muscle protein synthesis. The leucine threshold and protein distribution across meals are key variables. Burd NA et al., Journal of Physiology (2012); Moore DR et al., American Journal of Clinical Nutrition (2015); Witard OC et al., American Journal of Clinical Nutrition (2014).
