A similar proportion will buy a larger coffee than intended and buy chocolate at the till in petrol stations and newsagents
Burger King is currently promoting its calorific Long Chilli Cheese Burger and also offers a Fiery BBQ XL Burger.
The XL Burger comes in at 1,050 calories, which is more than half an adult woman should eat for an entire day.
It also has 28g of saturated fat, which well over the maximum figure recommended for an adult for entire day of 20g.
At KFC the ‘Big Daddy’ box meal for one person, which includes a fried chicken burger, large fries, a side dish and large drink, comes in at 1,430 calories.
And McDonald’s is offering larger burgers under its new, more upmarket, Signature Collection as well as its supersize ‘Big Tasty’ products.
The RSPH says similar triggers to indulge are used by coffee shop chains to sell bigger servings of hot drinks, some of which are laden with sugary syrups and toppings.
And the policy of petrol stations and newsagents to put chocolates and sweets at the tills is encouraging consumption of sugary snacks.