A new study says that kids who have full-fat milk every day have a lower BMI than those who rarely drink milk.
However, that's not the case for children who often drink medium-fat or low-fat milk, the study added.
The research showed that kids who drink full-fat milk every day weigh on average just over 4 kg less.
"This is an interesting observation, but we don't know why it is so. It may be the case that children who drink full-fat milk tend also to eat other things that affect their weight. Another possible explanation is that children who do not drink full-fat milk drink more soft drinks instead", said dietician Susanne Eriksson, author of the study.
The researchers also found a difference between overweight children who drink full-fat milk every day and those who do not. Children who often drink milk with a fat content of 3 percent are less overweight.
The study also showed that the children eat more saturated fat than recommended, but those children who have a high intake of fat have a lower BMI than the children with a lower intake of fat.
Eriksson investigated the nutrition, body composition and bone mineralization of 120 healthy 8-year-olds. Much of the results can now be used as a standard to determine what is normal for healthy children at that age.
The children recounted what they had eaten during the previous day, and answered questions concerning how often they ate certain foods. Various risk markers in the children's blood were also measured.
"Many of these children had been examined when they were four years old, and we discovered that their eating habits were pretty much unchanged four years later. It appears to be the case that eating habits are established early", Eriksson said.
The study found that 62 percent of the children had low levels of vitamin D in their blood. The general guideline value for all people for vitamin D is 75-100 nmol/l, but most children had less than this.
High levels of vitamin D are found in oily fish, while certain dairy products have been fortified with vitamin D. It can be difficult to obtain sufficient levels of the vitamin through the diet.
"We could not determine whether the children's level of vitamin D is correlated with their consumption of fish, but we did see that those children who ate oily fish, such as salmon and mackerel, at least once a week have higher values of the long-chain fatty acids EPA and DHA in their blood. This shows how important it is to eat such fish, instead of processed fish such as fish fingers", says Susanne Eriksson.
The study has been presented at the Sahlgrenska Academy.