Portion sizes must be reduced to combat obesity and reduce food waste, say health experts who are calling on restaurants to lead the charge themselves.

With projections putting the number of obese people in the UK by 2030 at about 26 million – more than a third of the population – the Chartered Institute of Environmental Health is calling for action from companies to tackle the problems associated with over-eating.

It’s a change in focus for health bodies that have previously put the emphasis on individuals to control their food intake.

Speaking to Sky News, Jenny Morris, policy officer at the professional body for environmental and public health, said portion sizes in the UK were “too big”.

“It seems obvious to me, that an easy solution is to only produce the amount of food that is going to be consumed or that is needed” she said.

”I think that it is business that needs to lead on it because it is business that is in control. It hasn't always been the focus up until now.“

There is also a financial incentive for companies to reduce the amount they put on the plate.

The cost of food being wasted in the UK, from the hospitality and food service sector alone, was estimated at £2.5billion per year in 2011, according to recycling charity WRAP.