Myth or fact

You need less protein as you get older

Short answerNo

By GyroscopeUpdated November 14, 20268 sources

No. Older muscle needs more protein at each meal to respond. In lab studies, men around 71 needed about 0.40 g per kg of body weight at one meal for the full muscle response, against 0.24 for men around 22. And up to 46% of US adults over 70 eat less than even the old minimum of 0.8 g per kg.

Why people believe it

It sounds logical. Older people are often smaller, move less and eat less, so their needs should shrink. The official RDA seems to agree, since it’s the same 0.8 g per kg at 75 as at 25. And appetite drops with age for many people, so eating less protein feels natural.

You may need fewer calories as you get older and move less. Protein doesn’t follow calories, though, because older muscle gets worse at using it.

Why older muscle needs more

Think of a radio with a weak speaker. To hear the same song at the same volume, you turn the dial up. Older muscle hears protein less clearly, so it takes a bigger dose to get the same response.

The PROT-AGE expert group named two reasons. More of the protein you eat gets used by the gut and the liver before it ever reaches the muscle. And the muscle answers less strongly to the amino acids that do arrive.

In 2015, researchers in Canada, the UK and the US pooled their lab studies where men drank between 0 and 40 g of protein and had their muscle building measured. In men around 22, it leveled off at about 0.24 g per kg of body weight. In men around 71, it took about 0.40 g per kg, and the response climbed more slowly on the way up.

For a 165 lb person, that’s 18 g at 22 and 30 g at 71. Three eggs (19 g) do the job at 22. At 71 the same breakfast falls short, and a Greek yogurt, two eggs and a slice of toast (32 g) clears it.

How much older adults actually eat

Many older adults already eat too little. In a US survey of 11,680 adults over 50, protein intake was lower in each older age group. Up to 46% of those 71 and over ate less than 0.8 g per kg, the old minimum. The people below it had more trouble with everyday physical tasks, and those over 70 had weaker grip.

That survey can’t prove the low protein caused the weaker grip. But it lines up with the lab studies and with what geriatric experts recommend.

The case for less

There’s one group where less really is right. People with severe kidney disease who aren’t on dialysis may need to limit protein, and PROT-AGE makes that exception itself. Kidney disease is more common with age, so if you haven’t had your kidney function checked, ask before you raise your protein a lot.

For everyone else, the evidence points the other way. A 2022 review of 74 trials found that adults 65 and over who lifted gained extra lean mass when they ate 1.2 to 1.59 g per kg a day.

lifespan.guide covers the other half of keeping muscle with age: why it isn’t too late after 50.