Half of smokers delay quitting for years because they worry about getting fat, a survey has suggested.
Fears over weight put kicking the habit on hold for seven and a half years on average, according to a Censuswide poll for Slimming World.
In this time, it is estimated some 41,000 cigarettes will be smoked at a cost of around £20,000, taking nearly a year off life expectancy.
Dr Jacquie Lavin, head of nutrition at Slimming World, said the results were "horrifying to learn".
Researchers quizzed 2,000 current and former smokers who said their main worries were comfort eating, boredom and simply replacing holding a cigarette with food.
A study in the British Medical Journal estimated one cigarette costs 11 minutes of life, meaning the delay period would cut 314 days off the average smoker's' life.
Dr Lavin added: "It's horrifying to learn so many people are carrying on smoking for many years simply because they assume they will gain weight if they give up.
"It's true that, without support, giving up smoking and managing your weight at the same time can be challenging.
"Your appetite and sense of taste comes back and you can be so used to having something in your hand you are tempted to reach for food instead of a cigarette.
"Smoking is the number one preventable cause of death in the UK, followed by diet related disease and obesity."
The survey found the average person smoked 15 per day while the average cost of 20 cigarettes was £9.40.