LABELLING food with exercise quotas could help dieters scoff 200 calories fewer each day, experts claim.
They say the move could help combat the nation's obesity crisis - with two in three adults too fat.
Scientists say current packaging is poorly understood by most shoppers and has little impact on choice.
Instead of just sticking calorie content on food and drinks, they want labels to tell customers how much exercise they would have to do to burn off what's inside the packaging.
So to burn off a small, 229-calorie bar of milk chocolate, you would need to do 42 minutes of walking, 22 minutes of running, 24 minutes of cycling or 12 minutes swimming.
Meanwhile, a packet of crisps containing 171 calories would require a 31 minute walk or 16 minute run to burn it off.
And a fizzy drink containing 138 calories would require a 26 minute walk or 13 minute run.
An analysis of 15 studies by Loughborough University experts suggests the approach can nudge consumers to make healthier choices.
They estimate if widely applied, it could help people shave 195 calories from their daily diet.
Writing in the Journal of Epidemiology & Community Health, lead researcher Professor Amanda Daley said better labelling could be an important weapon in the fight against obesity.
She said: "Physical activity calorie equivalent (Pace) labelling is a simple strategy that could be easily included on food or beverage packaging by manufacturers, on shelving price labels in supermarkets, and in menus in restaurants or fast-food outlets.
"It shows some promise in reducing the number of calories selected from menus, as well as the number of calories and the amount of food (grams) consumed.
"Public health agencies may want to consider the possibility of including policies to promote it as a strategy that contributes to the prevention and treatment of obesity and related diseases."
Previous studies have found diners are more likely to choose a healthier restaurant option if it says how many miles they have to walk to burn off their meal.
Experts at the University of North Carolina found volunteers chose low-at dishes when the menu detailed the distance you would have to go to burn fat.
The researchers do warn that the number of studies they included in their research was small, and the design of each varied considerably.
The amount of exercise needed to burn off 10 calorie-dense foods
Below are ten calorie-dense food and drinks and their activity equivalence.
Walking would be at a medium pace of 3-5mph and running would be at a slow pace of 5mph.
- Sugary soft drink (330ml can) containing 138 calories - 26 minutes of walking and 13 minutes of running.
- Standard chocolate bar containing 229 calories - 42 minutes of walking and 22 minutes of running.
- Chicken and bacon sandwich containing 445 calories - 1hr 22 minutes of walking and 42 minutes of running.
- 1/4 of a large pizza containing 449 calories - 1hr 23 minutes of walking and 43 minutes of running.
- Medium mocha coffee containing 290 calories - 53 minutes of walking and 28 minutes of running.
- Packet of crisps containing 171 calories - 31 minutes of walking and 16 minutes of running.
- Dry roasted peanuts (50g) containing 296 calories - 54 minutes of walking and 28 minutes of running.
- Iced cinnamon roll containing 420 calories - 1hr 17 minutes of walking and 40 minutes of running.
- One bowl of cereal containing 172 calories - 31 minutes of walking and 16 minutes of running.
- Blueberry muffin containing 265 calories - 48 minutes of walking and 25 minutes of running.
And most weren't carried out in real life settings, such as restaurants and supermarkets.
Duncan Stephenson, Deputy Chief Executive, Royal Society for Public Health, said small changes to labelling can help make a big difference to a person's weight.
He said: "This new research builds the case for introducing activity equivalent food labelling.
"Our own research showed that using this type of labelling did make people think twice about the calories they were consuming, and when compared with other forms of labelling, people were over three times more likely to indicate that they would undertake physical activity.
More on diet and weight loss
"This type of labelling really does put an individual’s calorie consumption in the context of energy expenditure, and knowing how out of kilter we sometimes are, this partly explains the record levels of obesity we face."
But Kate Halliwell, head of UK diet and health policy at the Food and Drink Federation, had some reservations.
She told The Sun: "Our companies have provided clear nutrition labelling on pack for decades.
"We would have some concerns that the information given would have to be an average, and the actual figure would vary greatly dependant on age, weight, gender and how fast a person is moving.
"Providing a calorie figure for the food will be much more accurate.
"And of course not all food has to be burned off, we use about 2,000 to 2,500 calories a day through our normal life.
"Careful research would be needed to see the impact of this information both in terms of food intake and exercise."