Everything under the sun has been linked to obesity. Now the sun itself, or the lack of it, is being blamed for people being fatty.
A team of scientists at Aberdeen University has found that Scotland's dismal weather makes it more difficult for people to shed those extra pounds. Their research suggests that overweight people tend to have lower levels of vitamin D in their blood than their slimmer counterparts, the Sunday Times reported.
The most natural source of vitamin D is from sunlight but, because the sun makes such a rare appearance in Scotland, fat people are less likely to benefit from this slimming aid. But even when it is sunny, excess body fat absorbs and holds onto vitamin D, preventing it from entering into the bloodstream. The absence of enough vitamin D in the blood interferes with the functioning of a hormone called leptin, which signals to the brain when the stomach is full.
The research, published in the scientific journal Bone, used questionnaires completed by 3,100 women living in northeast Scotland between 1998 and 2000. The data included estimates of how long the women had been exposed to sunlight over the previous year and the amount of vitamin D obtained from food sources such as eggs and oily fish. Researchers found that those with an average body mass index (BMI) of 34 produced 10% less vitamin D than people of average weight.
"Obese people had less vitamin D and the link between obesity and vitamin D deficiency was statistically significant," said Dr Helen MacDonald, from Aberdeen University's department of medicine and therapeutics, who led the study.
But Michelle McManus, 28, the Glaswegian singer who won Pop Idol in 2003, is not convinced. "I'm not discrediting anyone's research, I think it's important that this work is carried out, but the obesity problem is because people eat too much junk food.
"Look at America. The sun is splitting trees over there but there's still an awful lot of overweight people."