One in three people in the UK will be dangerously overweight within the next four years, according to a new government report.
Department of Health predictions, due to be published this week, suggest that 14 million people will be obese by 2010, bringing about a massive increase in the incidence of diseases such as heart disease, cancer and diabetes.
The report is expected to blame the worrying trend on an increasingly sedentary lifestyle and a pervasive reliance on junk food.
Experts told the Independent that the figures are "stark" and should act as "a warning to us all".
Tackling obesity is a government-wide priority, a Department of Health spokesman said, although individuals have responsibility for their own health and could make simple changes which would directly impact on their health.
"Our public health agenda is the first concerted attempt to seriously tackle rising levels of obesity," he told the Independent, referring to an urgent plan that is being drawn up to halt the rise in obesity.
"Huge progress has been made already in starting to change attitudes through the Five-A-Day campaign, the school fruit scheme, and more investment in school food."
Of particular concern are the growing rates of childhood obesity, with 22 per cent of girls and 19 per cent of boys between the ages of two and 15 predicted to be seriously overweight by 2010 unless drastic action is taken.
Largely to blame for this is the widespread abandonment of outdoor activities, such as cycling, with children preferring to play video games or surf the internet in their free time.