Half the schoolchildren in a Peruvian desert province were overweight, and one in four was anaemic. One in ten was both

For decades the worry about children's nutrition in Peru was that they were too short and too thin. A study published in Frontiers in Nutrition on 28 October suggests the picture in school-age children around Ica, a farming and agro-export province on the southern coast, now looks very different. The researchers, from the University of Valencia in Spain and the National University San Luis Gonzaga in Ica, call it the double burden of malnutrition: too much weight and too little of a key nutrient, side by side.

Between April and December 2025, trained nurses visited six schools in five districts, chosen to cover the city of Ica and the farming districts around it. They measured 656 children aged 5 to 13 (411 at rural schools, 245 at urban ones; average age 8.9), checked their haemoglobin with a finger-prick device and asked parents about water, sanitation and housing. They also went through each school kiosk with the Ministry of Health's checklist for healthy school food.

Classic undernutrition was rare: 1.4% of the children were stunted (too short for their age), 0.5% underweight and 1.1% thin. Excess weight was the norm. By the WHO's BMI-for-age charts, 26.2% were overweight and 24.7% obese, 50.9% in all, and the same share had a waist more than half their height, a simple sign of belly fat. At the same time, 23.5% were anaemic, nearly one in four, and 65 children (9.9%) were both anaemic and overweight or obese.

Rural children came off worse on two counts. Anaemia was more common at the rural schools (26.0% against 19.2%), and so was a large waist (55.0% against 44.1%), even though overall excess weight was much the same (49.1% rural, 53.9% urban). Children whose homes had no flush toilet were about twice as likely to be overweight after adjusting for age, sex and area, and those without piped water were more likely to carry belly fat. None of the household or demographic factors predicted which children had both problems at once.

One finding runs against a common idea. Elsewhere, obesity has been linked to iron deficiency, because the low-level inflammation that comes with excess fat raises hepcidin, a hormone that blocks iron absorption. In Ica it went the other way: anaemic children were less likely to be overweight (adjusted odds ratio 0.63). The authors suggest that anaemia here may mark a poorer or smaller diet overall. They didn't measure what the children ate, or test for iron deficiency or parasites, which are common causes of anaemia in Peruvian children, so the reason is unknown.

At the kiosks, sugary drinks, fried foods, sweets and packaged biscuits were widely on sale, and fruit, vegetables and healthy prepared food were less common, even though Peru's healthy-eating law for children (Law 30021) says school kiosks should favour healthy food and limit products high in sugar, salt and fat. None of the six schools showed any sign of restricting unhealthy products, and none displayed healthy-eating material. The study has clear limits: a snapshot rather than a follow-up, six schools chosen because they agreed to take part, and a kiosk check that recorded what was for sale, not what children bought. It was funded by Spanish public research programmes and the Ica university.