As a fitness professional, I hear a lot of food “confessions”.
Here’s just a sampling of this week’s shares (names omitted and comments paraphrased to protect the innocent…);
“I have no self control when it comes to chocolate”
“Why can’t I stop at just one cookie?”
“I get the worst cravings for PopTarts just before I get my period”
“Gotta have that mid-afternoon coffee and donut to make it through the day”
“I looked down from the TV to find an empty bag of chips on my lap. I don’t even remember eating them”
Frequently, these admissions are accompanied by feelings of guilt and shame and promises to exert more willpower in the future.
The thing is, willpower alone doesn’t usually lead to success. In my experience, willpower goes a lot further when one understands the underlying cause of the behaviour. And when it comes to food cravings, it’s all in your head.
Your brain that is. Your brain and the way your hormones communicate with it to direct your thoughts and actions.
The Science Behind Food Cravings
A long time ago human diets consisted primarily of plant matter and a little animal protein. Sugar, fat and salt were fairly rare commodities, although required for growth, reproduction and survival. Hence, human brains became wired to reward behaviours that resulted in the consumption of these scarce nutrients.
Not such a bad thing when sweet, fatty and salty were REAL foods (fruit, wild game, vegetables, seaweed) and difficult to come by.
Fast forward a few thousand years. The same reward circuitry exists, but the sweet, fatty and salty options available to us today are stripped of nutrition and readily available.
Think about eating something sweet, fatty or salty and the reward centre of your brain releases the pleasure-seeking hormone dopamine. Dopamine gets you excited about the possibility of eating a donut and motivates you to drive to the donut shop.
Eat something sweet, fatty or salty and your brain releases endorphins; opiate-like hormones that provide emotional relief, release stress and generally make you feel good.
Repeat the ‘anticipation-satisfaction’ cycle a few dozen more times and presto, you’ve created a habitual response; the automatic craving for a specific food in response to particular triggers.
But it gets worse. In addition to stimulating the pleasure centres in your brain, sugar also triggers a cascade of hormonal responses in your soma.
Eat something sweet and your pancreas release insulin, a hormone that tells the cells of your liver, muscles and adipose tissues to store energy for future use.
If the sugar load is light and your body is sensitive to insulin, your pancreas will release just the right amount of insulin to return your blood sugars to their normal, healthy range. Since elevated insulin levels also have a satiety function, you’ll probably feel satisfied with your meal and leave the table without feeling hungry.
If the sugar load is heavy but infrequent your body’s insulin response will not be sufficient to remove the excess sugars from the blood and much of it will be stored as fat. As fat levels rise in the body, fat cells release leptin, a hormone that tell your brain that you’re “fat enough” and it’s time to eat less and move more.
If, however, the sugar load is both heavy and chronic (as it is for many modern humans) three very bad things happen;
(1) your body relies almost exclusively on sugar for fuel (fat stores go untouched)
(2) your brain stops hearing the leptin message (a condition known as “leptin resistance”) and continues to seek out sweet and fatty foods because it thinks you’re not fat enough
(3) your cells stop hearing the insulin message (a condition known as “insulin resistance” or Type 2 Diabetes) so your pancreas produces more insulin than necessary to remove sugar from the blood, thereby leading to blood sugar crashes and intense cravings for foods that will rapidly increase your blood sugar level (exactly the foods that caused the problem in the first place)
The only way to break the cycle (and undo the hormonal and metabolic damage) of cravings and addiction is to drastically reduce your intake of the offending foods; cookies, chocolate, chips and baked goods (to name but a few).
Now that you understand the science behind food cravings (the WHY), you’ll probably want some suggestions as to HOW to break the cycle. Because this post is too long already, I’ll keep you hanging until next week…
In the mean time, please check out this post on ‘trigger foods’ and share your tips and tricks for overcoming food cravings in the comments section below!