Slim = sad. Fat = happy

If you think going on a diet is depressing, you are right. And here's the part that really hurts

It is the body type that millions yearn for. They seek slender, toned perfection, thinking it will bring sex, power and happiness. However, they should prepare to be disappointed - and deeply depressed.

A new study has revealed that, rather than being content and confident, slim people struggle to deal with life's woes. Anxiety and mental suffering often dominate their lives - to such a degree that they are much more likely to commit suicide than large people.

The startling new insight into the deep mental troughs many slender people sink into comes in a report led by psychologists at Bristol University. They teamed up with colleagues across Europe to study the lifestyles of thousands of people and the results were stark: thin people were far less happy than rotund ones.

Over a 16-year period, the ups and downs of more than a million lives were examined and it was found that as a person's body mass index (BMI) rose the risk of serious depression fell. And when the scientists considered more than 3,000 people who had committed suicide they found that their BMI was on average significantly lower than those who did not kill themselves.

Various other factors that could bias the results, such as socio-economic status, were taken into account.

"We were quite surprised as there is a view that people who are overweight may be stigmatised and made to feel depressed," said Professor David Gunnell, of Bristol University, one of the authors of the study, which is to appear in the American Journal of Epidemiology.

"Our findings provide some support for the idea that fatter people are at a reduced risk of the problems that lead to suicide."

That did not come as a surprise to those who warn about the dangers of losing weight.

Joanne Roper, of Hugs International, an anti-diet pressure group, said: "Slimming makes you miserable. Dieting can bring people down and make them obsessed with their body image. You've got to be happy with what you've got and not worry about things too much. It takes work but if you can accept yourself as you then you'll be happy generally."

Concetta Clarizo, 31, from Essex, said that when she lost weight it had not made her happy. "Dieting books always have very clear rules, which are eat less and exercise more and then you'll be normal and then you'll be happy. Well it's rubbish."

The daytime television presenter Fern Britton drew criticism when she insisted that she was "a jolly size 16" and said that diets did not make people happy.

Emma Hayes, 44, from Brighton, agreed. "Being thin is not a recipe for happiness," she said. "I've never dieted in my life and I'm wonderfully happy. I don't know many people that are happier than me."

The pan-European study revealed that for each 5kg per square metre increase in BMI, the risk of suicide decreased by 15 per cent.

Exactly why is not clear, although there are a number of theories. Some research shows that people with insulin resistance, a condition associated with a raised BMI, may have a reduced risk of depression and suicidal behaviour.

Insulin resistance is associated with levels of serotonin, the feel-good hormone. One of the main types of antidepressant drugs works by increasing the amount of serotonin.

It is possible, researchers say, that people who eat more have higher levels of serotonin, which may lower levels of depression. Other research has found a link between obesity and low levels of anxiety and depression.

"High BMI appears to be associated with lower suicide risk," said Professor Gunnell. However, he added: "Since a high BMI is also associated with an increased risk of cardiovascular disease, cancer, diabetes, and other important causes of morbidity and mortality, we would not recommend interventions to increase BMI to prevent suicide or increase levels of happiness."

SIZE MATTERS

Not thin Emma Hayes is 44, single and lives in Brighton. She is the owner of Emma Plus, a fashion store for larger women.

"Being thin is not necessarily a recipe for happiness. I've never dieted, and I'm wonderfully happy. I don't know many people happier than me. I think the thing is to be contented and accepting of who you are.

"Many of the things I have are due to me being large. I have my own business and I really enjoy it and I have beautiful clothes and I have my health.

"We laugh at work. One of my customers drove past the other day and saw us all dancing around the shop. Life is what you make of it.

Thin Concetta Clarizio is 31 and lives in Essex with her boyfriend. She shed pounds dieting but laments that it has not lifted her spirits.

"Being thin is not all it's cracked up to be. Getting there and staying that way can be a real mental drain for some. Dieting is about deprivation. It can make you more depressed than being obese.

"I tried diets with the food replacement drinks. I felt I was being punished and the portions were being reduced for no justifiable reason."