A quarter too thin, a quarter too heavy: in one Saudi city's middle schools, the habit that stood out was eating in front of a screen

Public health talk about children's weight usually means one thing: too much of it. A nursing team at the University of Ha'il in northern Saudi Arabia set out to look at both ends at once. Between October and December 2024 they visited four middle schools, one picked at random from each of four groups (east or west of the city, state or private), measured the height and weight of 268 pupils in grades 7 to 9 and asked them about meals, snacks, exercise and screens. The results appeared in Frontiers in Nutrition on 30 October.

After weighting the sample to stand for the pupils in those schools, 25.3% were underweight by the World Health Organization's growth reference for their age and sex, 24.5% were overweight or obese, and only about half, 50.2%, sat in the healthy range. The authors call this a double burden of malnutrition: undernutrition and excess weight in the same population, often the same classroom. Earlier national surveys they cite found about 11% of Saudi children and adolescents overweight and 9% obese, and close to 15% of adolescents underweight.

Then came the habits. Of everything they tested, one link passed their significance test: eating while using screens. Among pupils who said they never ate in front of a screen, 12.1% were overweight or obese; among those who sometimes did, 26.5%; among those who always did, 32.9%. Total screen time showed no such link. In fact pupils who reported more than two hours a day were, if anything, less often overweight (19.3%) than those reporting two hours or less (30.5%), though that gap was not significant either. Eating with a phone in hand, skipping breakfast, sweets, fast food and exercising only once a week all leaned the expected way for excess weight, but none crossed the line.

The authors are frank about how far this goes. Only four schools were sampled, which left the statistics so thin that their planned model, the one that would have checked each habit while allowing for the others, could not be fitted at all. Everything is a one-habit-at-a-time comparison, measured once, so it cannot show whether screen meals lead to weight gain or simply travel with other things at home. Habits were self-reported, about two thirds of the pupils were girls, and income, parents' education, sleep, puberty and total calories were not recorded. Underweight did not follow any of the habits, which suggests its causes lie elsewhere, from portion size to food insecurity. What the study does show is that a school health check that only looks for excess weight would miss half the problem.