Simply increasing physical activity levels alone is unlikely to reduce body weight in young children, and therefore will probably not prevent obesity, although it may set the stage for a healthier lifestyle, the results of a study conducted in Scotland suggest, Reuters reported. Instead, a combination of increased physical activity and other lifestyle changes like sticking to a healthy diet may be needed to stem the tide of obesity. "Many children are obese, even at preschool age," Dr. John J. Reilly from the University of Glasgow and colleagues note in the British Medical Journal. Given the general lack of evidence on appropriate ways to prevent obesity in this age group, Reilly's team enrolled 545 children from 36 nursery schools in the "Movement and Activity Glasgow Intervention in Children" or MAGIC trial. The trial was specifically designed to see if an increase in activity could reduce body mass index. Each week for 24 weeks roughly half of the preschoolers, who were an average of 4.2 years old at entry, participated in three 30-minute active play "worked outs" while at nursery school and their parents were encouraged to increase the child's activity levels at home. The other half of the children, serving as controls, followed their usual nursery school schedule. According to the researchers, the physical activity intervention had no significant effect on body mass index or on measures of physical activity and sedentary behaviors of the children. However, compared with control children, intervention children posted greater gains in motor and movement skills, which, the researchers say, may foster confidence in physical ability, perhaps increasing the odds of future participation in physical activity or sports. Summing up, Reilly and colleagues suggest that "successful interventions to prevent obesity in early childhood may require changes not just at nursery, school, and home, but in the wider environment. Changes in other behaviors, including diet, may also be necessary."