Canadian researchers have found that children who eat diet or low-calorie food can actually cause children to overeat, leading to obesity, according to a study published in the academic journal Obesity.
A team of researchers from the University of Alberta conducted a study on rats and found that animals learn to connect the taste of food with the amount of caloric energy it provides.
The team believes children who consume low-calorie versions of foods that are normally high in calories may develop distorted connections between taste and calorie content, leading them to overeat as they grow up.
The researchers, led by sociologist David Pierce, conducted a series of experiments that proved substituting low-calorie versions of foods and drinks led to overeating in young rats, including ones that were lean and ones that were genetically obese.
Adolescent rats that were also fed diet foods did not display the same tendency to overeat. The researchers believe the older rats did not overeat because they, unlike the younger rats, relied on a variety of taste-related cues to correctly assess the energy value of their food.
"The use of diet food and drinks from an early age into adulthood may induce overeating and gradual weight gain through the taste conditioning process that we have described," Pierce concludes.
Pierce added that his team's theory may explain the puzzling results from other recent studies, such as the one that found a link between diet soda consumption among children and a higher risk of obesity.
Melanie Kurrein, a nutritionist for Vancouver schools, regularly sees students eating diet foods that are no healthier that the full-calorie versions.
"Pop, whether it's diet or regular, doesn't have any nutritional benefit and it's often displacing or replacing more nutritional foods," she says.
Parents assume that "diet," "lite" and "half-fat" are better options for their children, when in fact they're often made with artificial sweeteners.
"They taste sweet but there's no nutrition coming in the animal and or child," says Kurrein.
Pierce says that parents should consider his team's "taste conditioning" theory and recognize that the tried and true ways to keep children fit and healthy -- ensuring they eat well-balanced meals and exercise regularly -- are the best ways to maintain a healthy weight.
"Diet foods are probably not a good idea for growing youngsters," he concludes.