After decades of increasing childhood obesity, things are now going in the opposite direction. A study from Sahlgrenska Academy shows that among 8–year–old boys in Sweden, the percentage of boys suffering from overweight or obesity has decreased to their lowest levels since the early 1990s.

“A levelling off of the childhood obesity epidemic has been shown before, but we are able to demonstrate clear reduction in mean BMI and also the frequency of childhood overweight and obesity,” says Maria Bygdell, researcher and PhD student at the department of internal medicine and clinical nutrition.

The research is based on data from the population–based study, BMI Epidemiology Study (BEST) in Gothenburg, with detailed information from the school health care regarding the height and weight of children born from 1946 and onwards.

This time, researchers chose to study boys. The idea it to conduct a corresponding study on girls.

In all, thirteen age groups were included, born at five year intervals during the period 1946–2006. Each age group studied consisted of 425 boys. When the researchers noted the trend reversal, they wanted to look into the most recent period in greater detail and therefore expanded the number of individuals in several of the younger age groups to approximately 6,500 boys per group of children.

“We noticed an indication of a decrease, but wanted to confirm that it really was a decline,” says Maria Bygdell.

The results were clear – there is a reduction in mean BMI, overweight and obesity. After an all–time–high in boys born in 1991, where 22.6 percent were overweight or obese at the age of 8, the numbers of overweight and obese have fallen successively. In the group of boys born in 2006, 19.4 percent were overweight or obese in the year of their 8th birthday.

“There is a trend reversal and that is positive. However, I don’t think we can sound the all–clear in any way. The levels are still very high, equivalent to those seen before the highest level,” says Maria Bygdell.

If we only look at the percentage with obesity, levels decreased from 9.3 percent in the group of 8–year–old boys born in 1991, to 7.6 percent among 8–year–old boys born in 2006.

“Based on the data we have, I can’t explain what caused the decrease. Increased awareness of the risks of overweight and obesity in children might have contributed, but this is sheer speculation. And we still have to continue working on reducing the percentage of children suffering from overweight and obesity,” says Maria Bygdell.

The study was published in International Journal of Obesity.