The Royal Society of Public Health has called for “activity equivalent” labelling to be introduced to show how much exercise would be required to burn off calories contained in food and drink.

Sample images of packaging issued by the society show pictures of stick men jogging, swimming and cycling, in each case accompanied by the number of minutes it would take to burn off the calories contained.

In the case of a 171-calorie packet of crisps, the equivalent activity given, based on British Heart Foundation figures, is 19 minutes of jogging, 23 minutes of cycling or 13 minutes of swimming. For a chocolate bar, the respective values are 40, 49 and 29 minutes and for a can of fizzy drink, 15, 23 and 13 minutes.

The RSPH says the move would help tackle the growing obesity crisis and cited research it commissioned from Populus showing two-thirds of people would be in favour of such a move. But a leading obesity campaigner suggested it was over-simplistic and did not address the risks posed by a bad diet.

Shirley Cramer, RSPH chief executive, said: “Although nutritional information provided on food and drink packaging has improved it is evident that it isn’t working as well as it could to support the public in making healthy choices. Activity-equivalent calorie labelling provides a simple means of making the calories contained within food and drink more relatable to people’s everyday lives, while also gently reminding consumers of the need to maintain active lifestyles and a healthy weight.”

Respondents to the survey were three times more likely to indicate they would undertake physical activity after viewing “activity equivalent” calorie labels than after viewing current “traffic light” nutritional labels alone.

Just over half (53%) of the 2,010 adults polled said it would cause them to make positive behaviour changes such as choosing healthier products, eating smaller portions or doing more physical exercise.

Dr Asseem Malhotra, cardiologist adviser to the National Obesity Forum, said he was all for encouraging activity but added: “What this sort of labelling doesn’t do is account for the fact that different calories have a different metabolic effect on the body,” he said. “What you don’t want is to give people the impression you can out-exercise a bad diet.”

One in three children is overweight or obese by the time they leave primary school and almost two-thirds of adults are overweight.