People who refuse to make lifestyle changes to improve their health may find free healthcare less readily available in the future.
Experts think free obesity drugs and surgery, dental care, fertility treatments and complementary therapies will be cut by 2020.
Their predictions come in a report by Friends Provident and the Future Foundation, which warns that over the next decade laws could come to reflect the fact that bad lifestyle choices are putting unreasonable strain on NHS.
The report – Visions of Britain 2020 – maps out the potential impact of people eating unhealthily, exercising too little and drinking too much alcohol, despite government health campaigns.
A poll for the report found Suffolk residents have the unhealthiest lifestyles, exercising the least compared with 10 other regions in the UK.
They are also least likely to take notice of their calorie intake and the least likely to follow recommended alcohol guidelines, according to the survey of 1,000 consumers.
Dr Sarah Brewer, a GP and medical journalist who was consulted for the report, said: "We all know that we should follow a healthy low-fat diet, eat at least five (portions of fruit and vegetables) a day etc.
"But how many actually do anything about it? Unless an unhealthy diet and lifestyle is penalised in some way, no one will change."
"Would welcome the idea if it could be enforced" – Elaine Boardman, Plymouth
"I strongly agree – people will be careless as long as they get everything free. There must be consequences, otherwise NHS won't get any co-operation" – Vijay, SW London
"From my own experience, this may be an unfair way of dealing with people. Whereas I eat healthily and exercise several times a week my weight is on the high side. On the other hand, my husband, who does not exercise (other than his remote-control hand) and eats fried food, crisps and sweets and generally a much greater amount than me, is slim. Should I be punished for being overweight, or should he be punished for an unhealthy lifestyle?" – Name and address withheld