Here's Why You Crave Certain Foods

Ever wondered why you crave hot chips or doughnuts but not, say, lentils?

It's Friday night and you're home from work after a long week. Do you:

a. Cook a nutritious meal with all food groups covered off.

b. Order a pizza because, well, Friday. And pizza.

Not to generalise here, but we're betting there are a lot more 'b's than 'a's most Fridays. After all, pizza falls squarely in the category of foods we crave.

A craving is defined as a powerful desire and when it comes to food, almost everyone has had one. And we're having one now with all this pizza talk.

But why do we crave them?

Well, according to science, cravings are partly driven by nature and partly by nurture. Recent research suggests that high fat, high carbohydrate foods (think: ice cream, fries, pizza, biscuits, cakes etc) light up reward circuitry in our brain more than foods that are either high in fat or high in carbs (as nature might supply them).

Er, no kidding science.

A study in the British Journal of Sports Medicine also suggests that sugar acts on similar pathways in the brain as addictive substances, which would explain some bingeing behaviours and use of food as a reward.

And if you say you crave those lentils we talked about -- listen up. Despite a popular theory suggesting that cravings are related to nutrient deficiencies, there's actually very little scientific support for that.

READ MORE: Bingeing On Junk Food When You're Drunk Is Actually Scientifically A Thing

Other biological factors come into play, too. Studies suggest that lack of sleep can drive up cravings. Sleep deprivation can make some food seem more enticing and mean we are less in control of our eating choices.

And then we have the learned response. If, as a kid, Friday night was family pizza night -- no judgement here -- then you may subconsciously have a hankering for pizza as an adult because you've paired "pizza" with "Friday" and "family" all your life.

And yes, it's true, when we say you, we mean we.

"It is possible to crave foods based on a positive past association with the food, such as enjoying a certain food with a loved one. There is also suggestion that the smell of foods can trigger past emotional memories," nutritionist and author Zoe Bingley-Pullen told 10 daily. "This may cause us to be more interested in such foods because they bring back happy memories. Therefore it only makes sense that we seek out those foods."

So say you want to relax at home -- that can trigger a craving for pizza because, in your head, you always associate couch time with pizza. Or maybe you watch a movie about a holiday and the craving strikes because you associate pizza with being carefree with cocktail in hand.

You may not even be aware that you formed these associations. But they're there.

READ MORE: Sniffing Chips Can Apparently Curb Your Cravings For Them

Then, of course, there are habits around food and unpleasant feelings. Breakup? Fight with a parent? Bullied at work? Since food can light up those pleasure centres in our brain, another association is formed.

"Yes there is suggestion food cravings are a result of conditioning," said Bingley-Pullen. "For example, if we come home stressed or sad and turn to certain foods, after repeating this pattern a few times, the next time we feel stressed or sad we are automatically conditioned to crave these foods."

So the question is, how do we break these habits?

"It depends on the cause," said Bingley-Pullen. "If it's psychological, breaking the habit and cycle by avoiding those foods when feeling stressed or down can be beneficial. This can be hard at first but is possible. Finding alternative ways to reduce stress and boost mood including exercise and meditation can be helpful!"

READ MORE: Here's Why You And Your Workplace Should Meditate

Martin Binks, PhD, associate professor and Director of the Nutrition Metabolic Health Initiative (HMI) at Texas Tech department of Nutritional Sciences also suggests that "If you de-pair the associations, the cravings dissipate."

He points to research among people who replace meals with shakes -- in essence, eliminating food cues (sights, smells, taste) while reducing calories -- which shows, amazingly, that they go on to report fewer cravings, not more.

"If it's physiological looking at your diet to make sure it's satiating enough is the first step," added Bingley-Pullen. "For example, if your diet is low in protein you will likely crave carbohydrates and comfort foods to feel full. Lifestyle is also important because if you lack sleep or burn the candle at both ends, you may crave sugar as a quick source of energy."

Feature image: Getty.