Spare a little thought for your health, the next time you log on to your computer -- it could make you fat, claims a new study.

Researchers at University of Copenhagen have carried out the study and found that staring at a computer screen can make people crave for sweet treats like chocolate cake and biscuits, the 'Daily Mail' reported.

According to them, the mental stress of computer work triggers changes in blood sugar and hormone levels that trick the brain into thinking it has worked off lots of calories that need replaced.

Lead researcher Jean-Philippe Chaput said: "Working on your computer is sedentary and doing nothing increases your weight. But use of them also increases your appetite as well so there is a double whammy in effect."

He added that office workers who want to keep trim should take regular breaks -- and even consider typing while standing up.

For their study, the researchers asked one group of female students to condense some text into an on-screen summary and other group to simply relax for 45 minutes. Those doing the computer-based task burnt just three more calories than the others.

But the second group ate much more food when given access to a buffet afterwards. In fact they took in an extra 230 calories. Chocolate and fatty foods were particularly popular. .

Experiments showed that the computer work made blood sugar levels fluctuate wildly and hunger hormones to rise. As a result, the students gorged on food they didn't need. In contrast, physical exercise leads to far fewer fluctuations -- meaning we are less prone to overeat afterwards.

Dr Chaput said: "The next thing is to look at new computer games like the Wii. The message is to use it to increase energy expenditure. If they over-compensate by eating more then they don't benefit.

"Maybe we are thinking we are doing a good thing for kids and teenagers but maybe they over-compensate by eating more and we need to know that.