The World Health Organisation (WHO) says by the year 2015, more than two billion adults will be overweight and 700 million will be classified as obese.

In recent years, doctors have focused on the growing rate of diabetes among children and young people.  But the most common kind of diabetes, type II, is more prevalent as people grow older and gain more weight.  Before you know it, there is more fat around the waist and hips than you remembered. 

The statistics are scary enough to make you want to stop eating immediately.  

Being overweight or obese is an expanding problem even in low and middle income nations.

Less physical activity and foods high in fat and sugar are a recipe for a global epidemic of diabetes, the WHO says.

Dr David Siscovick of the University of Washington in Seattle is one of the researchers who studied how body composition, the ratio of lean tissue to fat, and increased weight affected the risk of diabetes in more than 4000 adults, age 65 and older.

"If you were in the upper fifth of the population that we studied, the upper 20 per cent of the population in terms of multiple measures of adiposity [body fat], you had a four fold increase[d] risk of developing diabetes late in life," he said.

At the beginning of the study, none of the participants had been diagnosed with diabetes.  Researchers kept track of their body mass index, waist size, and waist to hip ratio over the next 12 years.

"Even among adults over the age of 75, having a higher body mass index was still associated with a two-fold increased risk of diabetes," Mary Biggs, University of Washington, Seattle said.

Men who were borderline obese had a five and a half times higher risk of diabetes than those who were just overweight.  For women, the risk was about three and a half times higher.  The experts believe this is because men tend to have more belly fat.

As hard as it might be, Biggs says, making sure your weight stays at a healthy level is the only way to keep the risk of diabetes down. "The results affirm the importance of weight control during middle age and suggest that weight control remains important into older ages in terms of reducing diabetes risks," she said.