The discovery that healthy eating guidelines of the past 18-years are wrong, now allows slimmers to enjoy a few more fatty or sugary junk food treats without guilt.

The current recommended daily calorie intake of 2,000-calories for adult women and 2,500 for adult men, according to a draft report by the Scientific Advisory Committee on Nutrition (SACN) says can be increased by 16%. This means it is safe for them to consume an extra 400-calories per day, equivalent to eating an average-sized cheeseburger or a couple of bags of salted crisps.

The revised guidance comes after researchers did a far more accurate assessment of how fat can be burnt through exercise. However, given the levels of obesity, the committee comprising of some of Britain's top nutritional experts recommends, eating more only if one exercises more.

Health campaigners and consumer experts worry the revised figures could send out the wrong message to over-weight people.

The introduction of new food-labelling schemes highlighting the calorie content of foods relative to guideline daily amounts (GDAs) is already under consideration.

Existing guidelines were formed in 1991 on the basis of advice from doctors and nutritionists, and if the committee accepts the current proposals on daily calorie intake for good health some foods will find themselves upgraded to a healthier rating.