Action on Sugar and Action on Salt, based at Queen Mary University London, suggested the tax should be levied on all calorie-dense processed food, the criteria for which would be set by the government.
This would be likely to include cakes and biscuits with especially high fat content.
The group said this would encourage manufacturers to change their products to be lower in calories, which in turn would help fight the rise of obesity in the UK. NHS Digital stats show there were 617 admissions in NHS hospitals in 2016-17 where obesity was as factor, which was an increase of 18% on 2015-16.
Katharine Jenner, campaign director of Action on Sugar and Action on Salt, said: “Manufacturers are simply not doing enough. If the government is really committed to helping the less well off, they need to tackle the food industry and a feasibility study needs to be undertaken without delay.
“An ‘excess calorie levy’ would encourage manufacturers to improve the nutritional quality of their unhealthy foods and most importantly, tackle the thousands who suffer the consequences of a poor diet, leading to obesity, Type 2 diabetes and cancer.”