The Science of Food Cravings

The Science of Food CravingsIt’s no secret that most of us occasionally have cravings for certain foods, usually foods that are high in calories or otherwise wouldn’t make the list of foods a nutritionist would approve of. Whether it be a craving for potato chips, chocolate or an order of French fries, succumbing to these cravings too often can add inches to your waistline. If only it were possible to face those cravings and say “no,” but sometimes it’s hard to ride out a craving. Ever wonder what causes them and why they’re so persistent?

Food Cravings May Be Partially Biological

Your brain may drive you to crave certain foods, especially if you’re not consuming enough calories. Back in time when food supplies were more limited, cravings for high-calorie foods motivated men and women to seek out calorie-dense foods to keep their energy level high so they could escape predators. These days we don’t have to worry about the availability of food, but some of that desire to eat calorie-rich foods may be still wired into your brain.

In some cases, cravings are a physiological response to a drop in blood sugar. This is your body’s way of telling you glucose levels are running low and it’s time to refuel – and it makes sense from a survival standpoint. In a study published in the Journal of Clinical Investigation, researchers found that when blood sugar levels drop, it activates portions of the brain that regulate the desire to eat, making you want to wolf down that piece of chocolate cake. When blood sugar levels are normal, areas of the brain that reign in impulses are more active.

Drops in blood sugar are more common for people who eat a diet high in simple carbohydrates without consuming fiber and protein at the same time. Simple carbohydrates cause a rapid rise in blood sugar and insulin spikes that trigger cravings for carb-rich foods. That’s why eating protein and fiber-rich carbs at regular intervals throughout the day keeps cravings in check for some people.

 Is It All in Your Head?

There’s also a psychological component to food cravings. Why do we crave chocolate more than Brussels sprouts? Chocolate contains a compound called phenylethylamine that has mood-elevating effects much like endorphins released in response to exercise. Craving chocolate may be your body’s attempt to “self-medicate” when confronted with stress. Fortunately, exercise also stimulates the release of phenylethylamine and endorphins so taking a run on the treadmill is a healthy way to make a craving to pass. In fact, a study carried out at Brigham Young University showed that 45-minutes of moderate to intense exercise in the morning helps reduce cravings for food.

There’s another way stress triggers food cravings. When you’re sleep-deprived or “stressed out,” it elevates levels of cortisol, a stress hormone released by the adrenal glands that lie just above the kidney. Cortisol increases the desire to munch on carb-rich foods as a way to maintain blood sugar levels during periods of stress. Carbohydrates also increase levels of the neurotransmitter serotonin. This has a mood-elevating effect, so some people are unconsciously using carb-rich foods to feel better when they’re under stress.

How to Control Cravings

Now that you know what causes cravings, how can you keep them under control? Here are some tips:

Start the day with a high-protein breakfast and eat a small snack with protein and complex carbs every three to four hours to keep your blood sugar stable. Avoid restricting calories too much even if you’re trying to lose weight.

Begin the day with an exercise session to reduce cravings later in the day. When a craving hits you during the day, get up and move around for five or ten minutes. Activity helps to refocus your brain until the desire to snack passes.

Make sure you’re getting at least seven hours of sleep – eight is even better. Lack of sleep raises cortisol levels. This can trigger cravings.

Watch the caffeine. Coffee temporarily suppresses appetite but too much it elevates cortisol levels and can trigger cravings.

The Bottom Line?

Cravings are part of life and one that can be challenging to control, but reducing stress, getting enough sleep staying active and keeping blood sugar levels steady can have a big impact.



The Journal of Clinical Investigation, September 12, 2011.

Br J Sports Med 2001;35:342-343 doi:10.1136/bjsm.35.5.342

BYU News Release. “BYU Study Says Exercise May Reduce Motivation for Food’’

Science Daily. “Comfort-Food Cravings May Be Body’s Attempt To Put Brake On Chronic Stress”


Related Articles By Cathe:

Why Women Crave Sugary Foods More Than Men

Three Types of Foods We Crave and Why

5 Ways to Naturally Curb Your Appetite That Are Backed by Science

Does the Texture of a Food Influence How Much You Eat?

Food Cravings? the Role Brain Chemicals Play

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