Kuk said the results were a reminder that our weight was not entirely in our control.

London - Women who are stressed put on weight because their metabolism slows down, scientists have shown.

Worrying about work pressures, your partner, your children or your friends could mean you will burn off 100 fewer calories a day.

Over the course of a year this could equate to a weight gain of almost a stone (about 6kg), according to US research.

Scientists from Ohio State University, in Columbus, studied 58 women whose average age was 53.

They filled in a detailed questionnaire answering whether they were stressed about their jobs, with their husband or partner, problems with the children or tension with friends.

The women then ate a 930-calorie Southern-style meal which consisted of a turkey sausage, eggs, savoury biscuits made from dough, and gravy.

After the meal, the scientists measured their metabolism – how long it took their bodies to burn calories – and their insulin levels.

They found that women who reported having one or more worries burned an average of 104 fewer calories in the seven hours after eating the meal than those who had none. Over a 12-month period this could lead to a weight gain of 11lb or 5kg.

The stressed women also had higher levels of insulin, which contributes to the storage of fat. To make matters worse, the authors say those who are stressed would be more likely to eat high-fat, comfort food.

Lead researcher Jan Kiecolt- Glaser, professor of psychiatry and psychology at Ohio State University, said: “This means that, over time, stressors could lead to weight gain.

“The participants burned fewer calories over the seven hours after the meal when they had a stressor in their life the day before the meal.

“We know from other data that we’re more likely to eat the wrong foods when we’re stressed, and our data say that when we eat the wrong foods, weight gain becomes more likely because we are burning fewer calories.”

Commenting on the size of the meal used in the study, she said: “This is not an extraordinary meal compared to what many of us would grab when we’re in a hurry and out getting some food.”

The researchers do not know what happens to men’s metabolism and body weight when they are stressed.

They suspect the findings would be slightly different because they have more muscle, which means their metabolism is different. Other studies have found that stress causes us to eat more – particularly sugary, high fat foods. Experts say this the body’s natural response to a threat.

Martha Belury, professor of human nutrition at Ohio State, who also carried out the latest study, urged both men and women to keep healthy snacks in the fridge or cupboard “so that when those stressors come up, we can reach for something healthy rather than going to a very convenient but high-fat choice”. - Daily Mail