The average portion of chips sold in Glasgow is 80 per cent larger than official guidance set out in 2002, new research has revealed.
Obesity Action Scotland (OAS) visited 30 takeaway outlets in the city in May, and found the average serving of chips to be 380g.
This compares with 210g as set out in official portion size guidance published by the Food Standards Agency in 2002.
Of the 40 samples bought, 37 were bigger - and one weighed 755g.
The smallest portion weighed 120g.
OAS has called for new regulations to control portion sizes, the introduction of mandatory calorie caps and mandatory calorie information on menus, and more half-size portions to be available.
Chips are one of the top five foods or drinks consumed by people outside of the home, according to Food Standards Scotland.
OAS programme lead Lorraine Tulloch said: “From our study, we see a portion of chips has grown significantly since 2002.
“Today’s average bag of chips contains around half of the recommended calorie intake for a woman for an entire day.
“It is no wonder that people can put on weight so easily.
“Let us start to improve takeaways and eating out, by ensuring people can opt for smaller portions and are aware of the calorie content of the items they are purchasing.”
Scottish ministers published a new diet and healthy weight plan last month, which includes the goal of halving childhood obesity by 2030.
It states: “With more than 30,000 out-of-home food outlets in Scotland, the role that the out-of-home sector can play should not be underestimated.
“Establishments that embrace healthier options with fewer calories, provide clear nutrition information and offer a greater proportion of smaller portion sizes will help Scotland to progress towards its dietary goals.”
Food Standards Scotland will consult on an “out-of-home” strategy, in parallel with the Scottish Government consultation on the promotion and marketing of junk foods in the autumn.
The consultation will focus on how to encourage calorie reduction and measures to encourage food outlets to provide better information to customers.