By Caroline Parkinson
Health reporter, BBC News
Most people need an incentive to lose weight or visit the gym.
Gym vouchers are one incentive being suggested
It can be the target of a special occasion, or the promise of a new outfit.
Employers are not usually involved - but under government plans, they might be.
The anti-obesity strategy launched on Wednesday sets out a series of measures to reverse the rising trend in obesity in England.
One idea is to involve employers in promoting healthy living, whether through "Well@Work" weight-loss competitions for staff, or with incentives like leisure vouchers.
Such measures would be aimed not only at improving individuals' health but also benefitting companies - who would have a more motivated and healthier workforce who took less time off.
The idea comes from the US, where many companies have introduced healthy living schemes, with some even offering financial incentives.
One three-month study of 200 people, carried out by independent researchers RTI International and the University of North Carolina, found offering cash payments for each percentage of weight lost was effective - with the highest payment of $14 (£7.17) being the best incentive.
RTI International's Dr Eric Finkelstein, an expert on the link between obesity and the economy, said US companies were looking at ways of cutting the burden of insurance payments for employers as well as having a healthier workforce.
But a spokesman for the Department of Health said it was not looking at offering people hard cash for going to the gym or lose weight.
She added the use of incentives - such as vouchers - was at a very early stage of development.
"We are working with the experts, looking at the success of schemes worldwide that have been used in the public and private sector to incentivise employers, organisations and individuals to encourage healthy living and improved physical activity.
"One way this has been to work is to encourage people to get fit with motivational interviews and incentives such as free access to leisure or health facilities."
'No lasting effect'
But research cited by the department as evidence such schemes could be successful actually showed no long term benefit.
The study of over 500 people in Newcastle in 1999 gave people motivational chats and, for some, leisure vouchers during a three-month study.
At the end of the study, 55% of those who had six interviews plus 30 vouchers entitling them to free leisure facilities had increased their levels of physical activity compared to 35% of those who only received the chats.
However, when the researchers went back to people a year after the start of the study, they found that these short-term boosts in activity levels had not been sustained.
Martin White, professor of public health at Newcastle University, who was one of the researchers involved in the study, said: "That research showed we can't assume that short-term interventions will have a lasting effect.
"We know how to get people active. The big challenge is to keep them active and to maintain that lifestyle.
"If someone is obese, doing activity for three months will be good. But if they then go back to how they were, it won't really have helped them."