It is already known that obese people are at an increased risk of developing a range of health conditions, such as heart disease and diabetes. However, a new study has found that if an obese adult was also obese during adolescence, their risk is even higher.

US researchers looked at over 1,500 severely obese people who were aged between 19 and 76. Severe obesity refers to people with a body mass index (BMI) of 35 or more. For a woman of average height, this is around 220lbs.

The participants stated what they weighed at the age of 18 and were then assessed for current obesity-related conditions.

Among the group, 42% had been a normal weight when they were 18 and did not become obese until they were adults. A further 29% were obese at the age of 18 and 13% were severely obese.

Almost all of the participants were found to have at least one obesity-related condition as an adult.

The study found that aside from the known risks, obese adults who were also obese teenagers had four times the risk of developing skin ulcers and swollen legs and three times the risk of developing kidney problems and walking difficulties.

They were also more likely to have asthma, diabetes, polycystic ovary syndrome and obstructive sleep apnoea compared to the obese adults who were not obese teenagers.

"Most people understand that the longer you carry extra weight, the higher your chances of developing heart disease or diabetes. But it seems that an even larger number of conditions should be added to the list of health problems that some obese teenagers will likely face down the road," commented the study's co-author, Dr Thomas Inge, of Cincinnati Children's Hospital Medical Center.

He added that as obesity among children continues to increase, ‘it is important for paediatricians to inform families about the short- and longer-term health issues linked to this weight gain'.

Details of these findings are published in the journal, Pediatrics.