He hypothesised that children who drank whole milk felt fuller than those who drank the same amount of low-fat or skim milk. If children do not feel full from drinking milk, they are more likely to eat other foods that are less healthy or higher in calories, he said. Therefore, children who drink lower fat milk may actually consume more calories overall than those who drink whole milk.
The study also found that children who drank one cup of whole milk each day had comparable vitamin D levels to those who drank nearly three cups of one per cent milk. This could be because vitamin D is fat soluble, meaning it dissolves in fat rather than water. Milk with higher fat content therefore has more vitamin D. There may also be an inverse relationship in children between body fat and vitamin D stores, as children’s body fat increases, their vitamin D stores decrease, according to the study.
“Children who drink lower fat milk do not have less body fat, and they also do not benefit from the higher vitamin D levels in whole milk. It is a double negative with low fat milk,” said Maguire. The study’s findings differ from Health Canada, US National Institutes of Health and American Academy of Pediatrics guidelines recommending two servings of low fat (one per cent or two per cent) milk for children over the age of two to reduce the risk of childhood obesity. Maguire said the findings indicated a need to closely examine existing nutritional guidelines around milk fat consumption to make sure they are having the desired effect.
“What kind of milk our children should be consuming is something we need to seek the right answer for,” said Maguire. Researchers studied 2,745 children ages two to six years attending well-child visits. They surveyed parents, measured height and weight to calculate BMI and took blood samples to assess vitamin D levels.
Of those studied, 49 per cent drank whole milk, 35 per cent drank two per cent milk, 12 per cent drank one per cent milk and four per cent drank skim milk. Less than one per cent of children drank some combination of the four types of milk. The study was published in the American Journal of Clinical Nutrition.