We all know that feeling: It begins as a little rumbling in the stomach and a thought in the back of our brains that just won’t go away. “Gosh, ice cream sounds so good!” Soon, the little rumblings turn into a roar. You absolutely, positively must have ice cream … right now.
You’ve just experienced a craving. And though cravings may seem harmless, they’re responsible for derailing many a diet. Those late-night yearnings for sweets (or fatty savory foods) are actually based in real science. As we begin to understand the science behind cravings, we can learn to control them and actually crave healthy foods.
The Science of Cravings
If you feel like the longing for those salty or sweet snacks is thwarting your best laid weight loss plans, take comfort in the fact that you’re not alone. Experts define a food craving as an intense desire for a certain food that usually lasts about three to five minutes and generally leans towards processed foods and junk food.1 Think it’s your stomach or your mouth that’s triggering these cravings? Wrong. In fact, it’s all in your head, specifically, your brain. A craving is a consequence of the parts of the brain that control memory, pleasure, and reward.
What leads to cravings?
The answer can vary. For example, one set of studies specifically focused on pregnant women showed that there was no single factor that served as a cravings cause above the rest. Research also suggested that most of the women surveyed reported having cravings before becoming pregnant, if not for the same items. The study’s authors did acknowledge the impetus for the pregnancy cravings seemed to be psychosocial – not physiological, though more research is needed.2 While pregnant women are often put in the spotlight for cravings due to stereotypes, this type of behavior can happen to anyone. A similar study showed that while a vast majority of female college-aged students reported having food cravings, just 32 percent of them linked their cravings to their menstrual cycles.3
When we eat a food we love, part of our enjoyment is due to hormone receptors. Sometimes, this stems from compounds in the food we eat, like phenylethylamine, tyramine, serotonin, tryptophan, and magnesium – which are all found in chocolate, a commonly craved food.4 When we eat a lot of a food we enjoy, the hormone receptors become less sensitive. The reward center of our brain is activated, and we feel elated. It’s a similar experience to that of a drug or alcohol addiction. In fact, brain MRIs of people experiencing food cravings showed increased activity in the hippocampus, caudate, and insula – the same areas of the brain involved in drug addiction. This is expounded by evidence showing that monotonous diets lead to significantly more cravings.5
Training Your Brain to Crave Healthy Foods
Most of the time, our body does a good job of telling us when we’re lacking a certain nutrient, the same way it may tell us that our blood sugar is low. If our energy reserves are running especially low, for example, we may need to increase our intake of B vitamins. And yes, there are times when our body is deficient in some nutrient, and we have a craving for a specific food rich in that particular nutrient. But this is different from regular food cravings – which are influenced by the pleasure and reward parts of the brain. It’s highly unlikely, for example, that the 97 percent of women and 68 percent of men who report having cravings all have serious nutritional deficiencies.6
So, what’s the trick here?
As it turns out, the answer sounds simple but requires a lot of hard work. We want to introduce more healthy foods into our diet, creating an association with cravings for healthy foods – rather than the junk food we’d normally go for. A six-month study showed that participants in a specific weight loss program eventually developed increased sensitivity in the brain for healthy, lower-calorie foods. Over time, as the subjects experienced increased reward and enjoyment of healthier foods, they began to crave them. Changes in our brains from “food addiction,” the study indicated, are not irreversible.7
In addition, improving your overall lifestyle may prove helpful. The healthier your life, the healthier your eating habits may become. One study said that regular exercise may actually help you eat healthier due to a mental phenomenon known as the “transfer effect.” This occurs when learning new skills and improving one area of your life causes a desire to improve in another one. In the study itself, exercise frequency was directly associated with an increase in fruit and vegetable consumption.8
Don’t Despair, Prepare!
If the thought of giving up your ice cream and chips sounds like too much of a mountain to climb, don’t despair. You can make some changes now that may help you manage your cravings as you work on training your brain to change its associations. For starters, purge your pantry of the unhealthy things you crave the most. Keep a few of your favorites around, in smaller supply. Why? Depriving yourself completely may backfire – and you’ll wind up standing in the kitchen at 2 a.m. with a gallon of rocky road ice cream in one hand, and a huge spoon in the other. Also, try to keep healthier snacks handy – at home, at the office, and in the car – to enjoy when a craving does pop up.
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