Women aged 65 and above find it more difficult than men of their age to stay strong and fit, say researchers.
This has been deduced from the findings of a study that showed that women find it harder than men to preserve muscle in old age.
Researchers behind the study - experts at Washington University School of Medicine in St Louis, Missouri, USA, and The University of Nottingham, UK - claim that theirs is the first study to show that it is more difficult for women to replace muscle that is lost naturally as they get older, due to key differences in the way their bodies react to food.
Michael Rennie, Professor of Clinical Physiology at The University of Nottingham, said: "Nobody has ever discovered any mechanistic differences between men and women in muscle loss before. This is a significant finding for the maintenance of better health in old age and reducing demands on the National Health Service."
In a paper describing their study, published in the Public Library of Science (PLoS) One, the researchers write that post-menopausal women participants in the study were found to be less able to respond to food to build muscle mass, whereas men of the same age (65-80 years old) were able to store protein in muscle.
They reckon that this change is perhaps the result of hormonal changes with the menopause, possibly changes in the hormone oestrogen that helps maintain bone mass in both women and men.
According to the researchers, their findings are consistent with other preliminary results showing that women are less able to respond to build muscle after resistance exercise, such as lifting weights in the gym.
They point out that younger men and women who had not reached the menopause did not appear to show any differences.
In their study report, the researchers also say that their findings highlight how important it is for older women to consume protein-rich foods like eggs, fish, chicken and lean red meat, in conjunction with resistance exercise.
"Rather than eating more, older people should focus on eating a higher proportion of protein in their everyday diet. In conjunction with resistance exercise, this should help to reduce the loss of muscle mass over time. There is also a case for the beneficial hormonal effect of limited HRT, although this has to be balanced against the other risks associated with such treatment," Rennie said.