THE US is supposed to be the home of king-sized servings in restaurants – but a new study has found that chip portions in Glasgow are almost twice the size they should be.

That’s hugely important in the fight against obesity because the familiar poke of chips is one of the top five foods or drinks consumed by people outside of the home, according Food Standards Scotland.

Obesity Action Scotland (OAS) is calling for portion sizes to be regulated after surveying 30 takeaways in Glasgow during May. It found the average serving of chips to be 380g, some 80 per cent larger than official guidance of 210g set out by the Food Standards Agency in 2002.

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Of the 40 samples bought, 37 were bigger than the guideline figure and one weighed a whopping 755g, while the smallest portion weighed 120g.

OAS concluded that there is a wide variation in the portion sizes of chips available to take away and that most of them are very high in calories and fat. One average bag of chips a week, equivalent to 983kcal, if eaten in addition to a normal diet could mean around 6.5kg of weight gain in a year.

They also found that the sizes of the majority of portions of chips from takeaway meals were much larger than typical chips servings in 2002.

OAS said: “Eating chips from takeaways puts people at risk of putting on substantial weight when they consume chips over and above their intake of other food and drink.”

As trends shift and lifestyles evolve, OAS said, we are increasingly becoming a nation of people who consume food prepared out of home, either in restaurants, drive-through burger bars, fast-food takeaways, sandwich or coffee shops or delivered.

In the last 10 years there has been a 53 per cent increase in places to eat out of home, with between 20 to 25 pert cent of our total calories consumed outside the house.

Adults who eat takeaway meals at home at least once per week consume 63 to 87kcal more per day, and in children, a weekly consumption of takeaway food was associated with consuming 55 to 168kcal more per day.

OAS said: “As the tendency to eat out of home becomes the norm, we need to change the rules on out of home as it is a potential game changer in our collective efforts to reduce obesity levels across Scotland.”

Following this latest study on chips, OAS has called for regulations to control portion sizes and introduce mandatory calorie caps. They say the consumers must be provided with more half-size portions.

The most controversial call is for regulation or limiting of access to unhealthy food through improved planning and licensing arrangements for the out of home sector, while mandatory calorie labelling should be on every menu – a move long resisted by the food and drink industry.

Paul Jaconelli, who has run a chip shop in Maryhill, Glasgow for more than 30 years, told the BBC: “The portion size is something that has evolved over the years. It is about the expectation of the customer. They would soon let you know if the portion sizes were too small and they would just take their business elsewhere.

“In my experience people come to the shop for the quality, the portion size and then the price. They want value for money.”

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.”

Food Standards Scotland is currently preparing measures on the out of home issue.

Head of Public Health Nutrition, Heather Peace, said: “Food Standards Scotland welcomes Obesity Action Scotland’s Chips to Go study, which adds to the evidence that portion sizes when we’re eating out can often be too big and can mean we’re eating more calories than we realise or need.

Food Standards Scotland will propose measures in a consultation later this year aimed at improving the food and drink available when we’re eating out.”