Extra protein in hospital did not speed recovery after broken bones in older adults

When older people break a hip, a pelvis or an arm after a simple fall, it is often a turning point: many never walk as well again or return to living on their own. Many of these patients are also poorly nourished, and medical guidelines recommend giving them more protein, the nutrient the body needs to rebuild muscle and heal wounds and bones.

But does extra protein during the hospital stay actually help? A small randomized controlled trial from Germany found no measurable short-term benefit. What it did show is how closely poor nutrition goes together with frailty, the general loss of strength and reserves that comes with age and illness.

What they did

• Who: 218 patients aged 70 or older (average 82, almost three in four women) admitted to a trauma centre in Tübingen with a fragility fracture, a break caused by a minor fall, typically of the upper thigh bone, pelvis, spine or upper arm. People with dementia were not included, because they had to give consent themselves.
• Screening: within two days of admission, two standard questionnaires checked whether people were at risk of malnutrition. 100 patients (46%) screened positive.
• The trial: these 100 were assigned by chance either to a protein-enriched diet (46 people) or to the usual hospital food (54). The enriched diet aimed for 1.5–2.0 grams of protein per kilogram of body weight a day, using protein-rich meals and snacks plus protein drinks with 20 grams per serving. It started a median of one day after admission and lasted until discharge.
• For comparison: the 118 patients who were not at nutritional risk ate the normal diet and were followed as a reference group.
• Outcomes: complications in hospital (such as kidney injury, urinary infections, pneumonia, blood clots), wound infections after surgery, how well people could walk at discharge, length of stay and where they went after the hospital.

What they found

• No difference from extra protein. Among the patients at nutritional risk, the protein-rich diet did not lower the rate of complications, did not improve walking at discharge, did not shorten the hospital stay and did not make a return home more likely.
• Complications were common in everyone: 45% of all patients had at least one, most often kidney injury (21%) or a urinary infection (19%).
• Wound infections were rare: 6 among 179 patients who had surgery. They were less frequent with the protein diet (2.6%) than with normal food (11.6%), but with so few cases the difference could be chance.
• Nutritional risk went with frailty. Patients at nutritional risk were frailer, had more chronic illnesses, walked less well before the fracture and more often already needed care. Only 46–50% of them could walk without aids before the fracture, against 80% of the others.
• A hard road for all. Almost every patient left hospital less mobile than before the fall, and only a quarter went straight home without extra help. A higher burden of chronic disease, not the diet, was linked to needing more care after discharge.
• No patient died in hospital, and no harms from the diet were seen.

What to keep in mind

• Too small. The team planned for 64 patients per group and ended up with 46 and 54. The authors say the trial could not reliably detect the effect it was designed to find, so it cannot rule out a real benefit, especially for rare outcomes like wound infections.
• Intake was not measured. Nobody recorded how much protein people actually ate or how many drinks they finished, so it is unknown whether they reached the target.
• Short. The diet ran only during the hospital stay, and nothing was measured after discharge. Building muscle usually takes weeks to months, often with exercise.
• One hospital, one health system. In Germany's payment system, hospital stays for these patients are fairly fixed in length, which makes differences there hard to see.
• The comparison with well-nourished patients is not randomized, so those differences show links, not effects. The trial was also registered only after it had run.

Why it matters

Guidelines rightly stress good nutrition for frail older patients, and this study does not argue against that. What it suggests is that a few days of extra protein in hospital, on its own, is unlikely to change how people fare right after a fracture. The authors see poor nutrition here mainly as a marker of overall vulnerability, and call for longer trials that combine nutrition with exercise and rehabilitation after patients leave hospital.