Evidence to link diabetes or non-insulin dependent diabetes mellitus (NIDDM) to obesity is mounting. Although the condition is, in part, thought to be genetic, many lifestyle factors are suspected of playing an important role as well.

Two major studies have endorsed earlier findings that obesity is a major cause of diabetes, which is the seventh leading cause of death in the US, and afflicts about 3 per cent of the adult population of Britain.

They were unable to agree on other lifestyle factors, but it looks as though smoking may be another contributor. Regular exercise could also be an important preventative, and may halve the risk.

More controversially, moderate drinkers seem to enjoy some protection from diabetes, although one of the research papers felt the finding needed to be treated with caution.

One study, by the Harvard School of Public Health, tracked a group of 41,810 healthy men for six years, 509 of whom developed diabetes in that time. They found that men who smoked more than 25 cigarettes a day almost doubled their risk of developing the condition while, conversely, those who drank moderate to high amounts of alcohol about three glasses a day of wine or beer seemed to reduce the risks (BMJ, March 4, 1995).

However, an English study, prepared by the Royal Free Hospital in London, found no definite proof between smoking and diabetes, although it also found that moderate drinking could be a preventative (BMJ, March 4, 1995).