Scottish children are among the most overweight in the world thanks to a diet of junk food and a couch potato lifestyle, health experts said on Tuesday, warning of possible severe health problems in later life.

Official statistics revealed a third of Scots children were classed overweight before they hit their teens, that one in five was obese and that more than one in 10 was rated as severely obese.

“Twenty percent of children classed as obese puts Scotland pretty much in the same league as the United States,” said Neville Rigby of the International Obesity Taskforce, an independent body that brings together obesity experts.

“We do see high rates of obesity in other countries, especially southern Europe, but what you see in Scotland is a worrying trend,” Rigby, the taskforce’s director for public affairs told Reuters.

The figures from Scottish Health Statistics showed that among Scottish children born in 2001, 20.7 percent were overweight by the time they were 3.5 years old.

While there was no one factor that causes childhood obesity the twin demons of poor diet and lack of exercise are considered key problems.

“Obesity often tracks deprivation. There is a correlation between low income and poor food choices,” said Dr. Beckie Lang, a public health nutritionist at Britain’s Association for the Study of Obesity.

“There is a problem of filling up on cheap, poor quality food.”

Levels of obesity in Scottish children rose over the last five years and have significantly surpassed levels anticipated 15 years ago when it was expected that 15 percent would be overweight, 5 percent obese and just 2 percent severely obese.

OTHER HEALTH PROBLEMS

Scotland has sometimes been dubbed “the sick man of Europe” for a health record that does not compare favorably with other European countries.

“If you look at heart disease and cancer rates, Scotland has not fared as well as other people,” Dr. Toni Steer, a nutritionist at the Medical Research Council (MRC) told Reuters.

The report warned that being overweight or obese during childhood could lead to physical and mental health problems in later life, such as heart disease, diabetes, osteoarthritis, back pain, low self-esteem and depression.

Rigby said more work needs to be done.

“The main issue is diet. We need children to be eating better quality food and we need to encourage people to move around more on bikes and on foot.”

He said it was not helpful that children faced a “barrage” of advertising and marketing from the fast-food industry.