Seven in ten fizzy drinks sold by supermarkets are on "special offer" a study found, as retailers have been accused of hypocrisy after launching public campaigns to cut sugar consumption.
According to research by consumer group Which?, 69 per cent soft drinks that would fall under the higher sugar band category of the government's proposed sugar tax were on promotion in stores, while over half (52 per cent) of confectionery was also on special offer.
This compared only a third of fresh fruit and vegetables which were offered on promotion.
MPs and health campaigners last night condemned supermarkets over promoting obesity by discounting fizzy drinks and foods high in sugar and fat.
Sarah Wollaston, chair of the health select committee, told the Daily Telegraph, "I hope the childhood obesity strategy encourages supermarkets to do the opposite and discount the healthy food and drink."
The bias of supermarkets towards discounts on unhealthy food comes even as a number had launched recent pro-health initiatives to convince customers that they were taking steps to improve their health.
For instance Asda and Waitrose had pledged to remove sugar from own-brand soft drinks while Sainsbury's had called on ministers to introduce compulsory targets to cut the amount of sugar in foods, as also ''clear, consistent guidelines'' on portion sizes.
The investigation also considered the proportion of total offers at major stores for ''healthier'' or ''less healthy'' food.
Around 53 per cent of the 77,165 promotions at Tesco, Sainsbury's, Asda, Morrisons, Ocado and Waitrose between April and June were on foods that were less healthy.
Any product with a red traffic light label for fat, saturates, sugars or salt as less healthy and automatically counted fresh, unprocessed fruit and vegetables as healthier.
In a separate survey, Which? found 29 per cent of consumers said they thought healthier food was more expensive, and gave it as the main reason for not having a healthier diet.