Too little protein at breakfast and lunch inhibits muscle growth in the elderly
Older people who want to build more muscle are often advised to eat more protein. That advice is correct - but too vague, according to researchers at the University of Birmingham in the UK. Better advice is to increase the intake of proteins at breakfast and lunch to a level of at least 40 grams of protein per meal.Study
For 3 days, the researchers analyzed the diet of 40 young people in their twenties, 40 people in their forties or young fifties and 40 people in their seventies.

In their study, which they published in Frontiers in Nutrition, the scientists focused mainly on the proteins the study participants consumed. They looked at the total protein intake, but also the protein intake per meal.

The older the study participants were, the lower their protein intake. But most older study participants also had a protein intake that, according to regular nutrition scientists [who have not kept up to date with the literature], was sufficient.

The picture became less positive when the researchers looked at the intake of proteins per meal. Only at dinner, the seventies received enough protein to increase the production of their muscles.
Young people need 20-25 grams of protein per intake to stimulate the production of muscle tissue. After consuming this amount, enough amino acids enter the blood to activate the anabolic machinery of the muscle cells.In the elderly, this machinery works less smoothly. Aged muscle cells only increase the anabolic machinery with an intake of 40 grams of protein.
"Most people are reaching the recommended daily allowance of protein, but our results show that a one-size-fits-all guideline for protein intake isn't appropriate across all age groups", first author Benoit Smeuninx says in a press release. [ March 16, 2020]

"Simply saying older people should eat more protein isn't really enough either. We need a more sophisticated and individualised approach that can help people understand when and how much protein to consume to support muscle mass."
Front Nutr. 2020 Mar 16;7:25.