Watching winter movies like Frozen can make people crave junk food, scientists say.
One study found that adults who watched a clip of a snowy forest had a greater preference for high calorie foods than those who watched a summer video.
The experts claim that cool images could stimulate an evolutionary instinct that humans developed in order not to starve to death in winter.
Many animals eat more than they need before winter, so their bodies can survive difficult hunting with fewer meals.
Icelandic researchers who led the study said Coca-Cola may have inadvertently benefited from the biological response with its famous Christmas advertisements.
You have called for future advertisements to avoid winter clues.
The 2013 film Frozen is one of the most successful of all time and is set in winter
The BBC series The North Water is about a whaling expedition to the Arctic and contains many ice scenes
In the study, published in the journal Food Quality and Preference, the Reykjavik University team asked hundreds of participants to watch either a video of a snow-covered forest filmed in winter or a lush green forest in summer.
The study was then divided into four parts.
In one branch of the research, participants completed 15 different puzzles with missing words related to food.
Those who watched the wintry video were more likely to fill in the blanks to form words related to high-calorie foods.
In another case, those who observed the cold conditions completed more words related to survival such as endure, endure, and fight than those who observed the summer walk.
Researchers said these two studies suggest that people associate high calorie foods and survival with the winter environment.
In a third study, participants watched the videos and then estimated the number of calories of different foods and said whether they wanted to eat them or not.
Women who watched winter videos showed a craving for calories, while women who watched summer clips showed no preference for one type of food over another.
Meanwhile, men preferred foods they believed were higher in calories, regardless of whether they were exposed to winter or summer stimuli.
And in a fourth test, participants completed the calorie estimation task and revealed their food preferences after watching a summer video, a winter video, or no video at all.
This study also supported winter clips pushing people towards higher calorie foods, a link that was not discovered in those who watched summer fitness or watched no video at all.
The results suggest that people developed a response to protect them from a time of food shortage.
Researchers say that although we don’t have to exert ourselves for the colder months to survive, our brains still have to catch up.
Overweight or obesity contributes to millions of premature deaths around the world each year and places an economic burden on health systems.
In the future, advertising and public campaigns should avoid showing winter scenes in case that leads people to junk food, the scientists said.
For example, a Greenpeace campaign showing the melting Arctic ice and a Coca-Cola winter advertisement are “filled with winter clues,” which the study found increases the preference for high-energy foods.
As a result, organizations and policy makers “may need to reassess their communication strategies,” the researchers said.
What should a balanced diet look like?
Meals should be based on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally whole grains, according to the NHS
• Eat at least 5 servings of different types of fruit and vegetables every day. Count all fresh, frozen, dried, and canned fruits and vegetables
• Basic meals based on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally whole grains
• 30 grams of fiber per day: This corresponds to the consumption of everything: 5 servings of fruit and vegetables, 2 wholemeal cereal biscuits, 2 thick slices of wholemeal bread and a large baked potato with the skin on
• Have some dairy products or milk alternatives (such as soy drinks) and choose low-fat and low-sugar options
• Eat beans, legumes, fish, eggs, meat, and other proteins (including 2 servings of fish per week, one of which should be oily)
• Choose unsaturated oils and spreads and consume them in small amounts
• Drink 6-8 cups / glasses of water daily
• Adults should consume less than 6 g salt and 20 g saturated fat for women or 30 g for men per day
Source: NHS Eatwell Guide