Protein in menopause: why requirements rise with age

Anabolic resistance, in plain terms

Muscle is constantly broken down and rebuilt. Protein in a meal stimulates the rebuilding side, and the size of that response determines whether muscle is maintained.

With age, the same quantity of protein produces a smaller response. More is needed to trigger the same muscle protein synthesis that a younger body achieved with less. That is anabolic resistance, and it is why the recommendation shifts upward rather than staying flat.

Combined with accelerating muscle loss across the transition, this is the mechanism behind the emphasis on protein in midlife guidance.

Why the standard number is a floor, not a target

The widely quoted adult recommendation was derived to prevent deficiency in the general population, not to optimise muscle maintenance in older adults.

Expert groups working specifically on ageing and muscle have proposed higher intakes for adults over 50, and higher again for those who are training or recovering from illness. This page does not state a figure, because the appropriate amount depends on body weight, kidney function, activity level and medical history, and a number taken from an article is a poor substitute for that.

Distribution matters

Muscle protein synthesis appears to respond to a threshold dose within a meal rather than to a daily total spread arbitrarily. Reaching that threshold at several meals produces a better response than reaching the same daily total with one large protein meal and two negligible ones.

The practical pattern this points to is protein at each meal rather than concentrated at dinner, which is how most Western eating is structured. Breakfast is typically the meal where intake is lowest.

Sources, and the plant question

Animal sources are generally more concentrated and contain a fuller spread of essential amino acids, particularly leucine, which appears to be the key trigger for muscle protein synthesis.

Plant sources work, but typically require greater total quantity and more attention to variety across the day to cover the same amino acid profile. Soy and legumes are the most complete plant options. Neither approach is wrong; the plant route simply needs more deliberate planning at this age.

Who needs caution

Anyone with reduced kidney function should not increase protein intake without medical advice, since protein load is handled by the kidneys and the appropriate intake may be lower rather than higher.

A high protein intake without resistance training does not build muscle. Protein supplies the material; training supplies the signal. This is why the two topics belong together and why protein alone produces disappointing results.

When to see someone

A dietitian can set an individual target, which is worth doing rather than adopting a figure from an article, particularly with kidney disease, diabetes or a history of disordered eating.

Ask for kidney function at a midlife review if you intend to increase intake substantially.