Four in ten older patients in a Pavia hospital study were malnourished. A third of them were overweight or obese

Picture a malnourished older person and you probably picture someone thin. Doctors tend to as well, which is why a high body mass index can end the conversation about nutrition before it starts. A study published in Frontiers in Nutrition on 28 October, from the SENIOR project in Pavia, Italy, suggests that shortcut misses a lot of people.

Between November 2023 and December 2025 the team enrolled 303 adults aged 65 and over at ICS Maugeri hospital in Pavia: 233 patients on a general medicine ward and 70 people attending an endocrinology and metabolic diseases clinic. Their average age was almost 77, three in four took five or more medicines, and most had heart or metabolic disease. People with severe dementia, active cancer treatment, swallowing problems or end-stage kidney failure were left out.

Each person was checked against international consensus definitions rather than a single number. Malnutrition used the GLIM criteria, which need at least one physical sign (unplanned weight loss, low BMI or low muscle mass) plus a cause such as eating less or ongoing inflammation. Sarcopenia, the age-related loss of muscle strength and mass, was built up from a handgrip test, a body composition scan by bioimpedance (or calf circumference when the scan wasn't possible) and a 4-metre walk.

The group was not thin. The average BMI was 28, almost two thirds were overweight or obese, and only 4.6% were underweight. Yet 39.9% met the criteria for malnutrition: 47.2% of the ward patients and 15.7% of the clinic outpatients. A third of the malnourished (33.0%) were overweight or obese, which works out to 13.2% of everyone in the study. Muscle told a similar story: 42.6% had the weak grip that flags probable sarcopenia, 30.9% had it confirmed, and 9.4% had sarcopenic obesity, low muscle function sitting under excess fat. That last group was found only on the ward, though 42 people who screened as probable sarcopenic obesity could not be confirmed either way because their body scan was missing.

The conditions overlapped. Malnutrition and sarcopenia came together in 29.2% of people. Older age went with much higher odds of malnutrition (about eight times higher at 85 to 99 than at 65 to 74), as did people rating their own physical health as poor. Low physical activity went with sarcopenic obesity. One finding runs against intuition: metabolic syndrome, the cluster of belly fat, high blood pressure, high blood sugar and abnormal blood fats, was more common in people without malnutrition (67.0%) than in those with it (49.6%), but it was most common of all in people with confirmed sarcopenic obesity (75.0%).

This is a snapshot, so it shows how often these conditions turn up together, not what causes what. It comes from one ward and one clinic in northern Italy, in a group that was entirely white European and already unwell enough to be in hospital or under a specialist, so it says little about healthy older people at home. Diet and activity were partly self-reported, and missing body scans limited some diagnoses. The authors' point is a practical one: in older people with heart and metabolic disease, a normal or high reading on the scales is not a reason to skip a nutrition and muscle check.