Diet foods may encourage chilhood obesity

Canadian researchers say diet foods may be contributing to the epidemic of childhood obesity because they may inadvertently lead children to overeat.

The researchers from the University of Alberta conducted tests on young rats, and found when the animals were given low-calorie versions of foods they overate regardless of whether they were lean or obese.

The researchers suspect that low-calorie versions of usually high-calorie foods disrupt the body's ability to use taste to regulate calorific intake and they say diet foods are probably not a good idea for growing youngsters.

Lead researcher Professor David Pierce says on the basis of the study findings, it is better for children to eat healthy, well-balanced diets with sufficient calories for their daily activities rather than low-calorie snacks or meals.

In the study the rats were fed either sweet or salty high-calorie or low-calorie gelatin cubes over the course of 16 days.

The researchers found that young rats given low-calorie foods began to overeat during their regular meals while older, adolescent rats also fed diet foods did not show the same tendency to overeat.

The researchers believe this occurred because the older rats, unlike the younger rats, were able to rely on a variety of taste-related cues to correctly assess the energy value of their food.

The younger rats learned to match tastes usually associated with food high in calories with low-fat alternatives, and so carried on eating to try to get their calorie count up when in fact it had already reached a healthy level.

Professor Pierce says the research highlights the importance of promoting a balanced diet and exercise as the best ways to keep children fit and healthy and says diet foods are not a good idea for growing youngsters.

Obesity is a significant risk factor for both type-2 diabetes and cardiovascular disease, and soaring rates present an increasing public health problem.

Experts say the study reinforces the need to encourage healthy eating habits in children from early in life by avoiding sweetened beverages, processed food and fast food.

They also recommend limiting TV time, fitting physical activity into the everyday routine and eating together as a family.

The study appears in the journal Obesity.