Study Links Fatigue With Junk Food

Published: 24 Apr 2017

Tired Woman at DeskResearch has uncovered new links between feeling tired and opting to eat junk food rather than healthy options.

The study has discovered that it’s all to do with food smells, and the way that brain activity reacts when deprived of sleep.

Junk food push

The Feinberg School of Medicine at Northwestern University, Chicago, put together some research looking at why we choose to eat junk food. Specifically, they found that when you are deprived of sleep, you brain activity is specifically enhanced when smelling food.

In order to test this hypothesis, they put together two groups of participants. The first group were allowed to sleep for 8 hours a day, while the second group were allowed to sleep for 4 hours a day. In the morning, they were tested on their reactions to smelling high-calorie foods. These covered both sweet and savoury foods, such as crisps or cinnamon rolls. They also rated the smells of non-food items such as fir trees.

The participants in both groups were then allowed to get a week of normal sleep. After this, they swapped over: those who had slept for 8 hours got 4 hours sleep, and vice versa. This way, the researchers were able to compare reactions for each individual.

Assorted PastriesWhat they discovered was that when you are fatigued, your brain finds food smells more intense than usual, which means that they appeal to you more. The fatty, high-calorie foods will appeal more than fresh produce and other healthy alternatives, particularly those which don’t have as strong a smell.

This supports earlier research and theories that a lack of sleep may have a direct correlation to weight gain. In other words, if you are struggling to sleep, or don’t have time to get the full recommended 8 hours, you might find that you are eating less healthy foods and putting on weight.

So, if you would like to lose weight and start eating better, you might want to plan to get to bed earlier in the future. It’s also possible that doctors could start looking at solutions such as prescribing sleeping pills for obese patients.

Implications for food

This certainly has strong implications for the food industry, especially those parts of it which have committed to helping their customers eat healthier. As we aim to cut out sugar and high-fat content from foods, particularly those marketed for children, it could be that more work is needed to make those foods appealing.

One option which those in research and development roles might consider is to artificially create smells in healthy foods. For example, consider a burger. A cheeseburger with full fat is an unhealthy option, but will smell delicious to the tired brain. An alternative version, perhaps made from Quorn, tofu, or another meat substitute, will be healthier with fewer calories. In order to encourage consumers to eat the alternative more often than the real thing, work needs to be done on ensuring that the alternative smells just like it – or perhaps even stronger.

It’s an interesting theory, so it would be perhaps a good plan to move forward with direct testing in this kind of area. Two foods which smell exactly the same – one with a higher calorie and fat or sugar content. Which would participants go for after 8 hours of sleep, or after 4 hours of sleep?

At this moment the research is still in its infancy, so we look forward to finding out more about the way fatigue affects the appetite. Food industry insiders will absolutely want to keep an ear to the ground.

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