This, researchers suggest, is because full-fat milk leaves children feeling more full, and makes them less likely to snack on unhealthy foods.
Children who drink full-fat milk were also found to have higher levels of vitamin D. This may be because vitamin D is soluble in fat, which there is less of in semi-skimmed milk.
The study, which has been published in the American Journal of Clinical Nutrition, involved 2,745 children between the ages of two and six.
Study participants who drank whole milk with a fat content of 3.25 per cent had a body mass index score 0.72 units lower than those who drank semi-skimmed milk with a fat content between one and two per cent.
This, the researchers say, could mean the difference between being a healthy weight and being overweight.
The study’s lead author, Jonathan Maguire, said: ‘Children who drink lower fat milk don’t have less body fat, and they also don’t benefit from the higher vitamin D levels in whole milk. It’s a double negative with low-fat milk.’
Research earlier this year found that people who drank full-fat milk were less likely to develop type-2 diabetes.
This is an observational study which shows a relation between consumption of full-fat milk over low-fat milk and body weight, as well as higher vitamin D levels. The study does not contain data to examine why these relations occur, though it can be assumed that the vitamin D levels can be related to the fat-soluble nature of vitamin D.
It is suggested that the higher fat content of milk causing children to be less likely to snack on higher calorie foods may be responsible for the lower obesity rates. While this idea stands to reason, further more in depth studies would be needed to prove this, as other factors may also be at play.