Teenage boys who sleep less than their bodies require have more body fat compared to sleep-deprived girls, an Otago University study has found.
The health researchers looked at the sleeping habits and body mass ratios in 386 boys and 299 girls aged between 15 and 18 at Otago secondary schools.
The study found an average 16-year-old boy who gets eight hours sleep would have a waist 1.8 centimetres bigger, and would carry 9% more body fat, than the same average-sized boy who slept 10 hours a day.
But lead researcher Paula Skidmore says boys who sleep less also have 1.4% more mass in their bones and muscles.
However, she says the effects of sleep deprivation have no effect on girls.
Dr Skidmore says they may be more aware of their diet and more in tune with a healthier lifestyle.
The study rules out the effects of food choice and entertainment, such as televisions and computers, the teenagers had in their bedrooms.