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What Science Teaches Us About Food Cravings [Facts and Great Tips]

Are we hard-wired to indulge in unhealthy foods?

 

Cravings (Hedonic hunger) are felt by everyone, in fact Mercia Levin Pelchat, of Monell Chemical Senses Center, found that almost 100% of young women and 70% of young men have had this feeling, this is cited in her article “food cravings in young and elderly adults” in the journal Appetite.

Some people are able to put these urges aside and continue with their clean eating regime. Others (Team Shape included) find these cravings almost impossible to fight. So we set out to find out more about why we have these cravings and what we can do to suppress this craving feeling.

What Do We Crave?

Before we delve into why we have cravings, let’s explore some common foods that people crave.

  • Chocolate
  • Bread
  • Fried Food
  • Sugar
  • Pizza

These are just a few foods that people often long for without actually having a feeling of hunger.

Hunger is the bodies’ response to a lack of food. Cravings, on the other hand, are more cognitive. They can occur whether you are hungry or not.

Cravings were once thought to be the bodies way of telling us that we had some deficiencies in our diet. Therefore, people often believed they needed chocolate or something sugary when they had low energy. Although not completely incorrect, this is not the primary reason for why we have the urge to gorge on certain foods. So I am sorry, you can’t use this as an excuse!

Let us know in the comments the foods that you crave!

Do Women Really Crave Chocolate?

Before we delve into the science behind why we crave, it is time to debunk a myth.

It is often believed men and women crave different things and so this must be biological….right? WRONG!

The Diabetes Association found that only 15% of men crave chocolate, whilst 40% of women long after it. Perhaps, to no surprise almost half of the women that claimed to crave chocolate, experience greater cravings during menstruation.

However, Dr.Julia Holmes an assistant professor of clinical psychology at the University of Albany found in her study in the “Appetite” journal in 2011, that there was no direct correlation between menstruation and cravings for chocolates. Therefore, it was debunked that deficiencies in certain nutrients leading up to a woman’s period are the root cause of these cravings.

It seems the real reason for why women crave chocolate is due to cultural influence and is psychological in nature. In the US in particular, chocolate is advertised as a woman’s guilty treat and this message sticks in the minds of women all over the states. The message is strong enough that it actually makes men associate chocolate cravings with womanly behavior and so they do not lust for it.

Another stereotyped gender bias is that it is only women that binge when they are emotional (men have feelings too okay!). When we are upset or angry, much like when we are stressed, cortisol levels increase, again increasing our hunger and subsequently we feel like we need to binge. Stop, you can prevent this emotional rollercoaster with these tips.

Why We Crave

Darn You, Ancestors

Our cravings are in part down to our ancestors. Millions of years ago, apes survived off sugar-rich fruit. The animals grew to like ripe fruit (with a higher sugar content) than unripe fruit as it supplied greater energy levels. Sugar also helps us store fat as it is broken down into glucose and fructose. When broken down, fructose activates processes that make the body want to increase fat stores.

In the past, when food sources were scarce and hunting was less reliable, hanging onto fat stores to prevent starvation was key.

Richard Johnson, a professor in at the University of Colorado and author of “The Sugar Fix” claims that during periods of starvation, a mutation occurred that caused apes and other similar mammals to store more fat after consuming sugars. This was a survival mechanism.

Those primates that gorged on high sugar fruits were more likely to survive and pass on their genes, therefore, we are biologically hard-wired to crave sugar.

Why We Crave – Brain Facts

The latest research, from the Monell Chemical Senses Center, accredits the craving feeling to 3 sections of the brain. The hippocampus, Insula and Caudate. All three appear to be activated during craving episodes.

The Hippocampus

The Hippocampus controls memory storage. It is responsible for affirming that we are familiar with and like a food.

The Insula

The Insula is stimulated by physical information and creates an emotional response. This informs us that the food we are about to indulge in is a “happy food”.

The Caudate

The Caudate is responsible for the release of opioid chemicals in response to the food we have just eaten. This means our body rewards us for ingesting sugary or fatty foods by providing us with feelings of euphoria.

Monell Chemical Senses Study

A study was published in December 2004, where 10 healthy volunteers were not allowed to consume anything other than a nutritional supplement beverage for the one-and-a-half days before a fMRI imaging session. fMRI (functional magnetic resonance imaging) is a technique for measuring and mapping brain activity.

The mundane diet was used to spark craving feelings during the fMRI sessions. A control group was allowed to eat whatever they wanted, along with the supplement. Both groups were then asked to give the name of a few foods that they loved. To trigger the cravings during the fMRI scans, names of the popular foods and the vanilla supplement were shown on a screen.

The individuals were asked to picture the food shown on the screen, including its smell, taste and texture. At the end of the scan, subjects were asked whether they had had any cravings. As expected, those that only had the vanilla supplement reported food cravings when picturing the likable foods but not when seeing the beverage and the 3 areas of the brain, listed above highlighted during the fMRI.

What part does the reward center play?

The core structures of the Reward Center are located in the Limbic System. This is comprised of the hypothalamus, amygdala, hippocampus, septal nuclei, and anterior cingulate gyrus. There are other nuclei which make up this complex system and you can find out more about the components of the reward center here.

The reward system induces the craving feeling by identifying a target. When the center is activated, dopamine is released. Dopamine creates a pleasurable feeling within an individual and so we believe we will receive pleasure from the craving. This desire blocks the pre-frontal cortex (which is responsible for impulse control and long term goal planning) and makes you want to give in to the craving and forget about the healthy lifestyle you have been living.

Your body then releases stress hormones that make you feel uncomfortable and you are tricked into believing the only way to feel better is by giving in to the craving. We are likely to repeat these behaviors as dopamine has rewarded us with a pleasurable feeling.

From an evolutionary and survival viewpoint, this is extremely important. If food is scarce and you grow hungry, you are rewarded with a pleasurable feeling when you find food. The good feeling becomes associated with the behavior that led you to the food. You will then want to repeat that behavior. Still with me? You can read more into the reward system here.

Additional Reasons As To Why We Crave

Stress

When we are stressed or in a state of high anxiety, our body produces a hormone known as cortisol. Cortisol increases the sugar in the blood that is used up as energy by the body’s cells and it aids in fat, protein and carbohydrate metabolism. It also blocks the release of leptin and insulin, increasing hunger.

The Memory Template

Memory structures have a lot to do with why we crave certain foods. When you experience a craving, we have a sensory memory for the food that will satisfy your feeling. The food has to match this memory to satisfy the craving. Our brain is almost telling us, nothing will satisfy you except pizza or chocolate pudding.

Cravings can become habits, we almost subconsciously reach for these junk foods without realizing it.

Why Do We Not Crave Healthy Foods?

Hopefully, from what you have read thus far, you will now know that you generally do not crave unhealthy food as you are lacking energy or are deficient in a macro/micronutrient but because you associate that unhealthy food with euphoria. Your memory of eating that food is pure happiness.

Yes, our ancestry roots have some part to play but it is really our own faults that we crave things like chocolate and pizza to this day, the food is in abundance and so we eat it regularly and our body is trained to associate indulging with a good feeling making it a habit and almost tricking our bodies into believing this is imperative for our survival like in the past.

This is psychological and so the next question to raise is….can we train ourselves to crave healthy foods?

Beat Those Cravings

15 Tips to Fight Cravings

We have compiled a list of lot’s of different tips to help prevent you from succumbing to your craving. Surely one of these is bound to work for you?

Distract Yourself

Taking your mind off the craving distracts the brain. The craving feeling is escalated when you begin to imagine what eating the food will be like and picturing its texture and taste. Much like in the Monell Chemical Senses study. So, try and think about something else. This will stop the release of dopamine and opioid chemicals so that you no longer crave.

Go for a walk, continue with some work you started, do a household chore, meet up with a friend, the list is endless.

Start Chewing

Research has shown chewing gum can help fight the feeling that you need sugar. In fact, you could eat 68 fewer calories at lunchtime and not over-compensate later on in the day. Many people blow their diets after a workout as they feel they should reward themselves for working out. Chewing gum, after a workout, can help deter those post-workout binges.

Save Yourself With Fruit

Ripe fruit, as discussed earlier, can still provide you with the sugar rush that you think you need from junk food but it also provides you with necessary vitamins and fiber. So stick to the what our ancestors used to crave and choose ripe fruit over sugary snacks.

Eat Regularly

If do not eat for prolonged periods of time, you may be tempted to start snacking. Eating more regularly can keep blood sugar levels stable. If you are on a low-calorie diet and are restricting calorific intake, within 3 days you may have reduced your appetite-reducing hormone leptin by 22%. So if you want to curb cravings, don’t do crash diets.

During the holiday season, if you are like me, you often don’t eat when you normally would but when it comes to mealtime, you begin your food frenzy. Cravings can be heightened during the holiday season as your house will more than likely have tantalizing treats inside, avoid these cravings with our 18-tips.

Quality Produce

Dark chocolate has been extensively researched and has some great health benefits. Reach for chocolates with a higher cocoa content. As previously mentioned, reaching for unhealthy treats can become a habit. Bad habits can be broken by substituting the unhealthy food that you are craving, with something that provides us with the same bodily response but is nutritious (dark chocolate instead of milk chocolate).

As you will see lower down, you may not even be craving chocolate, but magnesium instead. So grab some nuts to get you going.

Manage It With A Friend

Try and give up your unhealthy treats with a friend, chances are when they are craving, you won’t be. So help take each other’s minds off the craving.

Throw Away Temptation

If you don’t have sugary treats in your house, you can’t eat them. Try and cleanse your house of all the evil foods. This will be a struggle but it may feel rewarding afterward, you have effectively tossed out cravings and subsequently the emotional battle you will have when trying to deter yourself from snacking on that chocolate bar.

Little steps like not looking at a dessert menu at a restaurant will all help you avoid temptation. If you do not see the unhealthy item on a food menu, your brain will not start conjuring up images of the food and dopamine levels will not spike.

Manage Your Magnesium

Those that crave chocolate may be magnesium deficient. Although it is rare that people crave foods that are actually higher in magnesium than chocolate, like nuts, you may still be experiencing magnesium deficiency when craving chocolate. Try and increase your intake of legumes and leafy greens to get your magnesium in.

Sugar Detox

Completely getting rid of unhealthy sugar sources from your diet and going cold turkey instantly often works for some people. Although, the first 1-2 weeks can be tough, when you break this threshold the cravings will have diminished. This may be a more difficult approach than a slower, sugar detox but it may be more efficient if your plan is to completely cut out excess sugar and fast.

A sugar detox slightly differs from the cold turkey method as it is a gradual process. Slowly eradicate added sugar from your diet. If you are used to sugary breakfast cereals, try oatmeal with fruit or whole grain cereal. Replace your afternoon snacks of crisps or chocolate with nuts and veggies to dip in hummus.

Those Protein Gains

Protein is the most filling macronutrient, therefore, it is recommended to fill yourself up by increasing your protein intake, if you are less hungry, you are less likely to crave. Although very high protein intake does have it’s caveats, increased protein intake is associated with weight-loss.

Increased protein leads to increased secretion of satiety hormones (GIP, GLP-1) (hormones that tell your body you are full) and an increased thermic effect of food. The thermic effect of food is also known as diet-induced thermogenesis (DIT). DIT is indicated as a % increase in energy expenditure above the BMR. These DIT values are highest for protein of all macronutrients.

Bite-Sized Treats

If you do not want to completely clear your house of treats in case you go out and binge eat, try portion control. Instead of having a huge, family sized bar of chocolate, only keep individual bars in the house.

Sleep Is Key

It has long been known that inadequate sleep leads to hunger of the homeostatic kind (this is when you are genuinely hungry and your body requires energy). Recently, lack of sleep has been linked to hedonic hunger (increased cravings). So make sure you sleep!

HIIT

There has been recent research to suggest high-intensity training can reduce cravings. However, low-moderate intensity exercise can spike hunger.

Chill out

Stress eating is all too common. Try and take a moment to relax. Have a wearable? These often have relaxation properties, just check the features on the Apple Watch Series 3 & Fitbit Ionic.

Train your mind

According to Susan Roberts, a director of the Energy Metabolism Laboratory at the USDA and HNRCA the key to minimising cravings is to trick our brains into thinking of healthy food as a reward. She suggests the “iDiet”. Below is a description of how the iDiet works and a study that was conducted on the effect it had on cravings.

The iDiet replaces junk style foods that you may be used to consuming after exercising, with high protein and fibre foods that taste similar to what you are used to eating. Effectively, tricking the brain into releasing those same euphoric feelings but from nutritious foods.

Although the sampling size of subjects was small the results were conclusive. Those on the iDiet experienced activity in the reward center of the brain when they were shown images of healthy low-calorie foods and this activity was minimal when they saw pictures of traditionally favored, unhealthy foods. It is worth noting that this was the result after 6-months of being on the iDiet and so I certainly believe that habit plays some part in this.

Much like how bingeing is often habit, rather than cravings, for example rewarding yourself after exercise, the iDiet or anything similar will also become a habit. After some period of time you will learn to reach for healthy foods rather than junk foods as it has become integrated into your behavior.

You can read further on the Power of Habit on our blog.

Conclusion

Cravings do exist, however, not for the reasons most people believe. We are biologically hard-wired to feel happy after indulging in unhealthy foods, thanks to “survival of the fittest” and our surviving ancestors ( those that lived through periods of scarce food) passing on their genes.

The way our body and reward system reacts when eating these foods (with the release of dopamine etc) is really the reason why we crave.

I hope you find this informative and have developed quite a deep knowledge of the biology and neurology behind cravings and that going forward we may help you beat your craving.

Please leave a comment below if you found value in this blog.

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Charlie Farmer

Charlie is content writer and community manager at Shape.

20 Comments

  1. I love how it says 100% of women have experienced this. Haha! Also, I agree about getting good sleep. I can’t tell you how many nasty things I have wanted to eat late at night!

    1. Hi Emily,

      I was exactly the same. The cravings used to creep in when I was bored as well. So now I just try to keep busy. I read at night to take my mind off the thoughts of chocolate haha!

  2. The biological and psychology motivators behind cravings, especially for sugar, make the type 2 diabetes epidemic more understandable. What I don’t understand, is why this knowledge isn’t applied to those in a pre-diabetic or diabetic condition. My father is diabetic, and changing his eating behaviors and controlling his cravings was seemingly never discussed. Doctors just prescribe insulin shots, maybe some other medicines, and let their patients continue down a dark path of self-destruction. I guess that’s just easier and more profitable than trying to train people to resist their cravings and live a healthier lifestyle.

    1. Hi Stephen,

      We agree it would be very beneficial for those with diabetes to be educated about cravings. Has your father mastered resisting his cravings yet? Hopefully, some of the tips in this post will help him do so.

  3. I enjoyed this post because it is realistic and factual–some people do fight these feelings more than others! I would love to read more articles on Shape about maintaining healthy eating habits that, well, won’t drive a person crazy!

  4. I really liked this blog post and plan on using some of the tips you provided to help beat the cravings I experience way too often for chocolate and other sweets. I would definitely like to see more blog posts on this site about healthy eating, especially since I should really start eating healthier.

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