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Reduce default portion sizes in fast food restaurants to address obesity and type 2 diabetes, study urges

Simply reducing portion sizes in restaurants and fast food outlets could make a huge contribution to reducing levels of obesity and type 2 diabetes, according to new research.
The study, conducted by researchers at the University of Cambridge, finds that many people are willing to reduce their portion sizes in restaurants and fast food outlets. Because of this, the researchers urge for regulation of food portions, rather than trusting consumers to leave portions of their food.
“Our recent[…] review shows that people consistently consume more food or non-alcoholic drinks when offered larger-sized portions or packages or when using larger items of tableware [cups, plates and glasses],” said Dr. Theresa Marteau, PhD, director of the Behaviour and Health Research Unit, University of Cambridge.
“And the size of this effect suggests that eliminating larger portions from the diet could reduce average daily energy consumed by 12 per cent to 15 per cent among UK adults and by 22 per cent to 29 per cent among US adults.”
Are consumers open to smaller portions?
In a previous study, the researchers found that when customers in fast food restaurants were asked if they would like smaller portions, they were generally open to the idea.
“We consistently found that 14 to 33 per cent of customers accepted the downsizing offer, and they did so whether or not they were given a nominal 25 per cent discount,” said Janet Schwarz, PhD, Tulane University’s Freeman School of Business, New Orleans, Louisiana.”
The researchers presented several strategies to fix the problem. They include reducing default sizes for food and drink, limiting the availability of larger portions, and placing restrictions on prices that encourage consumers to purchase larger portions.
The study finds that reducing portion size is more effective than encouraging people to eat less.
Why we need smaller default portions
“We’ve had nutrition labels on food for decades and calorie labels on served meals in restaurants for years, and we just haven’t seen much impact on the number of calories that are served or consumed,” said Schwarz.
“Regardless of how much food people started out with, they each left about one ounce of food on their plate – meaning that both groups in our study ate just about everything that was served to them.
“We have strong preferences for things we like – we like sweet things, we like [high]-fat things, we like fried things – and just telling people that certain foods and bad for them is not going to change behaviour: we know that now.
Schwarz acknowledged that changing what people eat is very difficult, and that encouraging people to eat healthier portions is likely to be much easier.
“Once people see how little a smaller portion affects them, I think they will accept these changes, it’s just change per se that people are so averse to.”
Portion control and type 2 diabetes
Portion control is key to managing type 2 diabetes. It’s important to eat good foods, but it’s also important to eat the right amount of them.
Often, people don’t realise when they’re full, because they eat their food too quickly. It takes around 20 minutes for the body to realise that it has had enough food. So if you clear your plate quickly enough, you won’t realise that you are full.
Many people eat portions that are too large. If we reduce portion size, we often don’t realise the difference. Portion control, therefore, is a simple and straightforward way to reduce calorie intake, which aids both weight loss and blood glucose control.
The findings are published in the BMJ.

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