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Protein after 40: keeping the strength you use

From midlife, the aim is to keep the muscle you have. India's dietary guidelines say the body uses protein to build muscle only with physical activity or strength exercise.

KiloCare Team · · How we write and review

A grandfather in a navy kurta lifts his laughing grandson in a sunlit park, the two smiling at each other.

The park path is still damp at 7 in the morning. Your grandson spots you from the swings, runs at you with both arms up, and you lift him without thinking.

Later, on the bench, a question comes. Will you still lift him like that in 10 years? You may have heard that muscle simply fades after 40. A 2019 European review describes muscle staying steady in midlife and declining later. India's dietary guidelines pair protein with physical activity.

What happens to muscle from midlife

A European expert group on muscle health reviewed this in 2019. Drawing on grip-strength studies from the UK, it describes muscle mass and strength reaching their highest by about age 40. In midlife they are maintained, and they fall later, with older age. Its advice for middle age is to maintain muscle.[2]

An MRI study compared 468 adults aged 18 to 88. Muscle mass held steady until about the late 40s, then fell, mostly in the legs.[3] Because it compared people of different ages, it cannot show how fast any one person changes.

In a large US study of 1880 older adults, leg strength fell about 3 times faster than leg muscle over 3 years.[4] Those figures are for older adults, not for someone of 45 or 55.

India's National Institute of Nutrition (NIN) notes that muscle mass falls with age, and falls faster with inactivity. It says being active helps maintain muscle.[1]

Protein and strength exercise

Protein alone does not build muscle. NIN's 2024 guidelines say that "without adequate physical activity or resistance exercise, proteins will not be used for muscle building."[1]

The same page says protein supplements taken on top of a balanced diet will not build more muscle.[1] NIN pairs good-quality protein with a regular resistance exercise routine to build and keep muscle.[1]

How much protein after 40

NIN sets the allowance at 0.83 g of protein per kg of body weight a day for healthy men and women. That is about 54 g a day for a person who weighs 65 kg.[1] NIN's 2020 report on nutrient requirements says protein needs usually do not change for older people, but good-quality protein must be ensured with age.[6]

NIN's sample day for a man over 60 gives about 62 g of protein, and its sample day for a woman over 60 about 56 g.[1]

Both menus are built from ordinary food. They assume a man who weighs 65 kg and a woman who weighs 55 kg.[1]

For people over 65, an international expert group called PROT-AGE advises at least 1.0 to 1.2 g of protein per kg a day.[5] This is guidance for people over 65 only, and it is separate from NIN's allowance. The group says the body's response to the protein it eats declines with age. It recommends both endurance and strength exercise, at a level that is safe for each person.[5]

NIN advises care with high-protein diets for people who already have kidney disease.[1] If you have kidney disease or have been told to limit protein, ask your doctor how much protein is right for you.

Strength work, twice a week

NIN's activity guideline gives adults a weekly pattern. People over 60 do the same, with extra strength and balance work.[1]

2 days

a week, at least, of muscle-strengthening exercise for adults, working all muscle groups.[1]

3 days

a week or more of strength and balance work for people over 60.[1]

Strength work does not need a gym. NIN's examples include lifting weights or heavy objects, carrying a child, working with elastic bands, push-ups and squats.[1] The lift on the park path is on that list.

NIN also asks adults for 30 to 60 minutes of moderate-intensity aerobic activity on at least 5 days a week.[1] If you have been inactive, NIN advises seeing a doctor before you start an exercise programme.[1]

Protein at each meal

NIN names the foods. Pulses such as lentils, green gram, chickpeas, kidney beans and soyabean are rich in protein. Nuts and seeds, milk, eggs, fish and meat supply it too.[1] Pulses cost less than meat, eggs or milk.[1]

For people over 60, NIN says pulses, legumes, milk, fish, minced meat or egg raise the protein quality of a meal.[1]

A simple habit is to put 1 protein food in each meal. At breakfast, that could be curd or an egg. At lunch, it could be dal, chana or rajma. At dinner, it could be fish, chicken, paneer or another dal. PROT-AGE says the evidence on timing is not yet enough for specific advice.[5]

Plan your week

Tick each item as you plan the week, or copy the list.

A week that keeps your strength

The next morning, you walk the park path before your strength session. Your grandson runs at you with both arms up, and you lift him again.

India's 2024 dietary guidelines set one allowance for healthy men and women: 0.83 g of protein per kg of body weight a day. For people over 65, an international expert group, PROT-AGE, advises at least 1.0 to 1.2 g per kg a day. If you have kidney disease or have been told to limit protein, ask your doctor how much protein is right for you.

Not on its own. India's dietary guidelines say that without physical activity or resistance exercise, protein will not be used for muscle building. They also say protein supplements on top of a balanced diet will not build more muscle.

India's dietary guidelines list lifting weights or heavy objects, carrying a child, working with elastic bands, push-ups and squats. They ask adults to do this on at least 2 days a week, and people over 60 to add strength and balance work on 3 days or more. If you have been inactive, see a doctor before you start.

Sources

  1. ICMR-NIN Expert Committee. Dietary Guidelines for Indians - 2024. Hyderabad: ICMR-National Institute of Nutrition; 2024. Available from: nin.res.inCited atp. 62, Guideline 9p. 59, Guideline 8p. 59, Guideline 8p. 57, Guideline 8p. 58, Guideline 8pp. 103 to 104, Figs 16.1 and 16.2pp. 103 to 104, Figs 16.1 and 16.2p. 60, Guideline 8p. 70, Guideline 10p. 70, Guideline 10p. 70, Guideline 10p. 69, Guideline 10p. 70, Guideline 10p. 70, Guideline 10p. 59, Guideline 8p. 59, Guideline 8p. 101, Guideline 16
  2. Cruz-Jentoft AJ, Bahat G, Bauer J, Boirie Y, Bruyère O, Cederholm T, et al. Sarcopenia: revised European consensus on definition and diagnosis. Age Ageing. 2019;48(1):16-31. doi:10.1093/ageing/afy169. PMID: 30312372. Available from: pmc.ncbi.nlm.nih.govCited atSarcopenia development: Time course
  3. Janssen I, Heymsfield SB, Wang ZM, Ross R. Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr. J Appl Physiol. 2000;89(1):81-8. doi:10.1152/jappl.2000.89.1.81. PMID: 10904038. Available from: pubmed.ncbi.nlm.nih.govCited atAbstract
  4. Goodpaster BH, Park SW, Harris TB, Kritchevsky SB, Nevitt M, Schwartz AV, et al. The loss of skeletal muscle strength, mass, and quality in older adults: the Health, Aging and Body Composition Study. J Gerontol A Biol Sci Med Sci. 2006;61(10):1059-64. doi:10.1093/gerona/61.10.1059. PMID: 17077199. Available from: pubmed.ncbi.nlm.nih.govCited atAbstract
  5. Bauer J, Biolo G, Cederholm T, Cesari M, Cruz-Jentoft AJ, Morley JE, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013;14(8):542-59. doi:10.1016/j.jamda.2013.05.021. PMID: 23867520. Available from: pubmed.ncbi.nlm.nih.govCited atAbstractAbstractAbstract
  6. ICMR-National Institute of Nutrition. Nutrient requirements for Indians: recommended dietary allowances and estimated average requirements, 2020. A report of the expert group. Hyderabad: ICMR-NIN; 2020. Updated 2024. Available from: nin.res.inCited atp. 306, Nutritional needs for the elderly