Lifestyle

7 Signs of Low Protein Most People Blame on Getting Older

By Mike Harper · October 29, 2026

Legs that feel weaker on the stairs, a scrape that lingers for weeks, hair that seems thinner in the brush. Many people treat these as ordinary parts of aging. Sometimes they can point to a diet that is short on protein and calories.

Protein matters at every age. MedlinePlus, the National Library of Medicine’s consumer health site, says you need protein to help your body repair cells and make new ones. The National Institute on Aging adds that proteins are used to build and repair tissues, and also help your body fight infection.

When people go a long time without enough protein and calories, doctors call it protein-energy undernutrition. The Merck Manual says it is common among older adults in hospitals, nursing homes and long-term care facilities, and that about 1 in 7 older adults living in the community eat fewer than 1,000 calories a day, which is not enough for adequate nutrition.

These are signs described by the Merck Manual’s consumer and professional editions.

Weaker muscles. Merck says undernutrition reduces muscle size and strength, making it harder to exercise or work. It also explains that older adults already lose muscle tissue with age, a condition called sarcopenia, and that undernutrition and less physical activity make that loss worse.

Wounds that heal slowly. The professional edition of the Merck Manual says wound healing is impaired, and that in older patients the risk of pressure ulcers increases.

Swelling. If undernutrition is severe, Merck says fluid may build up in the arms, legs and abdomen.

Thinning hair. Merck describes hair that becomes dry and sparse and falls out easily.

Thin skin and easy bruising. Merck lists thin, dry skin that loses its elasticity, along with a tendency to bruise easily.

More infections. Merck says the immune system is weakened, which raises the risk of infections. In older adults, it adds, undernutrition also raises the risk of fractures, problems after surgery and pressure sores.

Fatigue and feeling cold. Merck lists fatigue and an inability to stay warm. People may feel weak and unable to do their normal activities, and it notes irritability, apathy and, particularly in older adults, impaired mental function.

Several things make shortfalls more likely later in life, according to Merck. Older adults tend to feel full sooner and have less appetite, and the senses of taste and smell fade, making food less enjoyable. Dental problems such as ill-fitting dentures can make chewing harder. Depression, dementia, stroke and some medicines can cut appetite or make eating difficult. People who live alone may be less motivated to cook, and some cannot easily get to a store.

Doctors can usually diagnose undernutrition by asking about diet and weight loss and doing a physical exam, Merck says. The blood test most often used measures albumin, which falls when people do not get enough protein.

Food is the first fix. MedlinePlus says healthy adults should get 10% to 35% of their daily calories from protein, and that one ounce of meat, fish or poultry, one large egg, a quarter cup of tofu or half a cup of cooked beans or lentils each provide about 7 grams. The National Institute on Aging suggests a variety of protein foods, including lean meats and poultry, seafood, eggs, beans, nuts, seeds and soy products.

The institute also offers practical help for common roadblocks to eating well. It suggests seeing a dentist if chewing is a problem, sharing potluck meals or cooking with a friend, and eating at a nearby senior center.

This article is for general information and is not medical advice. Talk with your doctor if you notice these signs or are losing weight without trying. This article was produced with the assistance of AI and fact-checked against the sources cited by LightWave Reports.