The government has launched a fresh attempt to tackle obesity in England by appointing a "minister for fitness".
Caroline Flint will be encouraging people to change their lifestyle
Public Health minister Caroline Flint has been given the task of getting people to boost their activity levels.
She wants people to build physical activity into their daily routines to create a healthier nation in the run-up to the 2012 Olympics.
Figures due out this week are set to show that, if nothing changes, a third of men will be obese by 2010.
Since 2003, obesity has risen by 38% in adults, the Department of Health report is expected to show.
And by 2010, it is thought it will forecast that 22% of girls and 19% of boys between the ages of two and 15 will be chronically obese, suggesting that the government may miss its obesity targets.
It is expected to show that girls under the age of 11 are particularly at risk.
Ms Flint will be working across all government departments to develop a new fitness strategy for England.
She told BBC Radio 4's Today programme: "I have been given the role of looking across government departments as to how we can better look at the policies we have and how we spend our money to enable people to improve their health.
"What is important is that people do recognise that there are some pretty small changes that they can make in their lifestyle in terms of physical activity that can start making a big difference to their health.
"And I think that that is important, because a lot of people think that they have to go to the gym five times a week and if they can't do that, they can't do anything - and that is just not true."
Earlier this summer, the government launched its Small Change Big Difference initiative, encouraging people to make small changes to their lifestyle in order to boost their long-term health.
HOW TO STAY HEALTHY
Eat regular, balanced meals
Eat at least five portions of fruit and vegetables a day
Avoid foods that are very high in sugar and/or fat
Eat less than 6g of salt/day
If you drink alcohol, drink it in moderation
For adults: 30 minutes moderate activity five times a week
For children: an hour a day of moderate activity
Prime Minister Tony Blair joined the campaign by pledging to make lifestyle changes such as using the stairs instead of the lift, visiting the gym more often and boosting his intake of fruit and vegetables.
But Conservative MP and former shadow home secretary Ann Widdecombe said: "I think you do have to ask whether the government has a big role to play in this.
"I think it has a role, but not the decisive role. I don't think that this (obesity) will be solved by government dictate."
Dr Ian Campbell, medical director of the charity Weight Concern, said that it was crucial that obesity was tackled now.
He said: "In the 1980s something like 6% of men were clinically obese, now we are looking at projections of something like 30% of people being obese by the year 2010.
"The cost of dealing with obesity throughout the NHS already runs into billions of pounds each year, and with the current rate of progression of obesity itself and the diseases it causes, the cost to the NHS is going to rise at an incredible rate.
"And it is highly likely that unless we deal with the problem in a way that actually reduces rates of obesity and the diseases that it causes then we will see the NHS being unable to cope both in terms of resources and finances - in fact the NHS could be heading towards bankruptcy."
A spokeswoman for Diabetes UK said: "If obesity rates continue to rise at such a rapid rate, the number of deaths due to diabetes will increase in line with this.
"We're delighted to see the commitment voiced by the government on tackling this huge problem. But we want to see these words turned into actions."