British men heavier than they were in 1986

London: Britain's festive traditions of stuffing, pudding and booze may not have changed much since 1986, but the physique of those consuming them certainly has.

The average British man has piled on abount 7.7 kilogrammes in weight between 1986 and 2000, according to new research.

A study published by Oxford University reveals a remarkable level of weight-gain among men who are eating more and exercising less.

The British Heart Foundation (BHF), which funded the study, described the results as evidence of a "ticking time bomb for male health" that would lead to a greater risk of diabetes, heart disease and stroke.

Scientists analysing changes in food consumption found that an increase in food intake over the 15-year period studied accounted for a 4.7kg increase in the average male's weight.

The actual observed increase of 7.7kg was much more than expected from the extra calories consumed, and partly explained by a reduction in physical activity.

The study found that in contrast to weight gain among men, the increased weight of women during the same period of 5.4kg was entirely explained by the fact they are eating more.

More than half of all adults were currently either overweight or obese.

A total of 25 per cent of men in England were classed as obese in 2008, the most recent data available, compared with only around seven per cent in 1986-07, the study said.

The study, in the British Journal of Nutrition, speculated that "sedentary behaviour" such as watching television may be on the increase.