Shoppers attracted to promotions in supermarkets are far more likely to be obese and buy less fruit and vegetables than those who ignore them, according to new research.
Almost three in 10 (29%) food and drink items in UK supermarket baskets are bought on promotion, the study of the shopping habits of more than 16,000 people found.
Those shoppers who are the biggest consumers of food bought on promotion are 54% more likely to be obese than those who shun promotions.
These shoppers also buy a fifth more unhealthy food and drink that is high in fat, sugar or salt than low promotional shoppers.
The report, from Cancer Research UK, found that a promotion-loving family with two adults and two children buys an extra 11 items per month that are high in fat, sugar or salt.
On balance, bargain-lovers buy much more sugar and less fibre than low promotional shoppers. They also buy less 30% less fruit and a quarter fewer vegetables, which are often not on promotion.
Researchers found that shopping for promotions was the same across all demographic groups, and did not vary according to income.
The report concluded that promotions tend to be for less healthy food, with almost half of all chocolate, crisps, popcorn and savoury snacks bought on promotion.
Promotions tend to increase the amount people eat, which can lead to obesity, it added.
It said: “High promotional shoppers buy more from typically less healthy food categories like cakes, confectionery, crisps, sugary drinks and puddings.
“This is at the expense of foods in healthier categories such as fruit, vegetables and unsweetened yoghurts.”
Being overweight or obese is linked to 13 types of cancer, including breast and bowel cancer, and excess weight and obesity accounts for around 6% of all cancer cases in the UK.
After smoking, being overweight or obese is the second leading preventable cause of cancer and is predicted to overtake smoking as the leading cause of the disease in women in around 25 years.
According to Cancer Research UK, obesity costs the NHS around £5.1 billion every year.
Professor Linda Bauld, Cancer Research UK’s prevention expert, said: “Promotional items offer people a wealth of tempting yet unhealthy food and drink choices when doing their weekly shop.
“With cut-price deals on things like chocolate, biscuits, cakes and fizzy drinks, it’s no surprise that people who buy more on promotion have a greater likelihood of being obese.
“With young children frequently being the ones who suffer from the effects of these purchases, introducing restrictions is important for their future health.
“We know that more than one in five enter primary school overweight or obese, yet the number worsens to around one in three when they leave.”
Alison Cox, director of cancer prevention at Cancer Research UK, said: “The Government’s proposed 9pm ban on junk food ads is a step forward in fighting childhood obesity.
“Now we want to see restrictions on price promotions for unhealthy food and drink items, as well as those strategically-placed at checkouts. This will help families to make healthier choices.
“There isn’t one magic fix for the problem, but removing these incentives to buy unhealthy food is key to changing it.”
Andrew Opie, director of food and sustainability at the British Retail Consortium, said: “Retailers have led the way in tackling obesity through clear labelling, healthier choices and improving the nutritional balance of products.
“Furthermore, the sector is looking closely at the current Government consultation on childhood obesity to see what more could be done to ensure we are both delivering great value and promoting the health of our customers.”
A Department of Health and Social Care spokesman said: “This research supports what we already know – promotions for sugary and fatty foods make it much harder for people to make healthier choices for their families, and encourage them to spend more on less healthy products.
“We are consulting on restrictions for promotions of foods high in fat, sugar and salt – including placements of such foods by checkouts.
“Tackling childhood obesity is part of our Long Term Plan to ensure the sustainability of the NHS – backed by £33.9 billion every year by 2023/24.”