It also showed young people felt under pressure to eat or drink these products.
Cancer Research UK said a 9pm watershed on TV adverts would be the most effective way to reduce HFSS eating. ‘On-demand’ services, online and radio should be included in any update.
Broadcast marketing restrictions remain the way forward for UK policy to have a positive impact of children’s dietary choices and weight outcomes, it added.
Junk food and ad relation
Cancer Research UK
Dr Jyotsna Vohra, head of the Cancer Policy Research Centre at Cancer Research UK who led the research, said industry wouldn't pump hundreds of millions into catchy adverts if it didn't get people to eat more.
“Broadcast regulations in the UK haven't been updated since 2008, and our research shows that the current restrictions clearly aren't working. With today's teens spending more time in front of screens than any other activity apart from sleeping, curbing exposure to junk food ads on streaming platforms as well as TV will be key to helping teens make healthy diet choices and reducing obesity rates."
On average, young people watched 21 hours of television a week with adverts, with just over half viewed on streaming platforms. However, obese participants watched around 26 hours (equivalent to one extra advert a week).
Seeing just one extra broadcast advert per week predicted a large amount of HFSS eating and drinking (around 60 HFSS items more/year) estimated at almost 350 calories/week.
Given the average junk food adverts seen was six, this would apply on average to those who see just one such advert per day.
People with obesity said they saw more adverts across all three mediums. On average, they saw one extra broadcast advert, two extra offline non-broadcast adverts and half an extra ‘added-value’ advert than their healthy weight counterparts.
The survey found offline non-broadcast marketing does not warrant the same policy prioritisation as broadcast though it may be an element in the wider approach to obesity.
Eight of the ten food and drink brands young people recalled most have at least one HFSS product in their top sellers indicating the imbalance between healthy and unhealthily messaging, said Cancer Research UK.
Food and drink categories in the study were confectionery, cakes/biscuits, sugary drinks, energy drinks, crisps, desserts, takeaways, ready meals, fried potato products, flavoured yogurts, milk drinks, sugar sweetened cereals, fruit, vegetables and diet carbonated drinks.
Broadcast marketing was also perceived as healthy, fun, popular and tempting, particularly amongst those with overweight, obesity or from deprived communities.
It is the second report based on data from the Youth Obesity Policy Survey of 3,348 young people by Cancer Research UK.
It looked at broadcast marketing (television, radio, streamed television); non-broadcast, offline marketing, excluding ‘online’ marketing (price promotions, print media adverts, billboards and posters) and ‘Added value’ marketing (celebrity endorsement, sponsorship, competitions).
The first correlated television advertising with a substantial and consistent risk of eating increased amounts of HFSS products.
Obesity rate by 2045
In other work presented at the European Congress on Obesity in Vienna this week, researchers said almost a quarter (22%) of people will be obese by 2045 (14% in 2017) if current trends continue.
In the UK, if the pattern continues obesity will rise from 32% today to 48% in 2045, said researchers from Novo Nordisk, Steno Diabetes Centre and University College London.
Dr Alan Moses of Novo Nordisk Research and Development said prevalence of obesity and diabetes is projected to increase dramatically.
“Despite the challenge all countries are facing with obesity and diabetes, the tide can be turned - but it will take aggressive and coordinated action to reduce obesity and individual cities should play a key role in confronting the issues around obesity, some of which are common to them all and others that are unique to each of them.”
Another study found eating a diet high in plant-based and low in animal-based foods may protect against obesity in middle aged and elderly people.
Erasmuc MC Rotterdam scientists examined the association between varying degrees of plant-based diet and body mass index (BMI), waist circumference, fat mass index (fat weight relative to height), fat-free mass index and body fat percentage over the long term in 9,641 middle-aged and elderly adults (average 62 years) from the Rotterdam Study - a population-based analysis in the Netherlands.
“Our study suggests that a more plant-based and less animal-based diet beyond strict adherence to vegan or vegetarian diets may be beneficial for preventing overweight/obesity in middle-aged and elderly populations,” said Zhangling Chen.
DOPS and social media influence
Meanwhile, Spanish researchers have developed a food-based score strongly associated with long-term risk of overweight or obesity across adulthood.
The Dietary Obesity Prevention Score (DOPS), which uses measures of dietary intake obtained by food-frequency questionnaires, could help individuals improve eating habits and raise awareness of dietary risks.
Finally, research from the University of Liverpool highlights the negative influence social media has on children's food intake.
A total of 176 children, aged between nine and ten, were randomly split into three equal groups and shown artificially created, but realistic, Instagram pages of popular vloggers.
One group was shown images of the vlogger with unhealthy snacks, the second saw the vlogger with healthy snacks and the third images of the vlogger with non-food products. The participants' subsequent intake of snacks (healthy and unhealthy options) were measured.
Children in the group that viewed unhealthy snack images consumed 32% more kcals from unhealthy snacks specifically and 26% more kcals in total (from healthy and unhealthy snacks) compared with children who saw the non-food images.
There was no significant difference in total kcal or healthy snack kcal intake, between children who saw the Instagram profile with healthy images and those who saw non-food images.
PhD student Anna Coates said the findings suggest marketing of unhealthy foods, via vloggers' Instagram pages, increases children's immediate energy intake.
"Tighter restrictions are needed around the digital marketing of unhealthy foods that children are exposed to, and vloggers should not be permitted to promote unhealthy foods to vulnerable young people on social media."