Obese teens don't need to lose large amounts of weight to lower their risk of developing diabetes, according to a new study.
Researchers found that obese teens who reduced their body-mass index (BMI) by 8% or more had improvements in insulin sensitivity, a measure of how well the body processes insulin and an important risk factor for developing type 2 diabetes. BMI is a measurement of body fat based on height and weight.
"This threshold effect that occurs at 8% suggests that obese adolescents don't need to lose enormous amounts of weight to achieve improvements," study co-author Dr. Lorraine Levitt Katz, a paediatric endocrinologist at the Diabetes Center for Children at the Children's Hospital of Philadelphia, said in a hospital news release.
"The improvements in insulin sensitivity occurred after four months of participating in a lifestyle-modification program," Katz said.
The study included 113 teens, aged 13 to 17, whose average BMI at the start of the study was 37.1. People with a BMI of 35 to 40 are classified as severely obese. None of the teens had type 2 diabetes at the start of the study, but their obesity placed them at high risk to develop the disease in the future.
The teens were put on a weight-loss program that used family-based lifestyle changes. They and their parents were taught about healthy eating habits and encouraged to increase their levels of physical activity. The teens and their parents attended weekly group counselling sessions and the parents were encouraged to support their children's lifestyle changes and to be healthy-lifestyle role models.
The study reinforces the importance of lifestyle changes in helping teens lose weight, the researchers said.
They also noted that the 8% reduction in BMI needed to improve insulin sensitivity is "achievable" and easy for doctors to track.
The Nemours Foundation outlines how obesity and overweight affect teens' health.