By Mark Hyman, MD
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If you’re overweight, there’s a good chance you’re addicted to certain foods.
It doesn’t mean you’re gluttonous, weak-willed or a bad person. It means your biology has learned to crave junk food.
Food addiction is usually framed as an emotional issue. But readily available, intensely addictive sugary foods can hijack your hormones, taste buds and brain chemistry.
Research shows that these sugars light up the pleasure center in your brain, which can cause addictive cravings. What else could explain these facts:
- 70% of Americans and nearly 20% (and growing) of the world’s population are overweight.
- 1 in 2 Americans battles “diabesity,” a range of imbalances that includes mild insulin resistance, prediabetes and type 2 diabetes.
- So many of us eat foods we know aren’t good for us and that make us feel sick, bloated and guilty — and then resort to fad diets.
Programmed to store calories
We’re biologically programmed to eat lots of hyper-palatable sweet or fatty foods, then store the excess calories as belly fat to sustain us through scarcity.
But what saved us as hunter-gatherers doesn’t work for us today.
Our bodies certainly need the starches and sugars found in healthy carbohydrates: veggies, whole-kernel grains and low-glycemic fruit like berries.
But the refined carbs and sweeteners filling processed foods like bread, pasta and chips basically turn into sugar in our bodies.
These foods spike blood sugar, trigger cravings and drive us to seek out more of the substance that gave us that “high.” They also leave us struggling with weight and feeling sick.
The proof is in the milkshakes
A powerful Harvard study reveals the addictive nature of sugary foods. It proves that foods with more sugar, which quickly raise blood sugar (foods with a “high glycemic index”) trigger the brain’s pleasure center: the nucleus accumbens.
Activating this center makes us feel good and drives us to seek out more of whatever gave us that feeling.
In the study, researchers gave 12 overweight or obese men, ages 18 to 35, a low-sugar, low-glycemic milkshake. Four hours later, they measured activity in the nucleus accumbens, along with blood sugar and hunger levels.
Several weeks later, the same men got another round of milkshakes. This batch tasted and looked the same, with the exact same flavor and texture, and the same amount of calories, protein, fat and carbs. But it was higher in sugar and had a higher glycemic index.
Without exception, the high-sugar, high-glycemic-index milkshake caused a much greater spike in blood sugar and insulin levels, and increased hunger and cravings four hours after they were consumed.
But the breakthrough finding was this: For every single participant, when the high-glycemic shake was consumed, the nucleus accumbens lit up like a Christmas tree.
The low-glycemic shake caused no such response.
Foods that spike your blood sugar
You can probably guess that table sugar and sodas, juices, sports drinks and vitamin waters have a high glycemic index. But you may be surprised to learn that:
- One serving of a popular tomato sauce contains 2.5 teaspoons of sugar — more than two Oreos.
- Your average single-size commercial yogurt has more sugar per serving than a can of Coke.
- The main ingredient in most barbecue sauces is high-fructose corn syrup.
In fact, about 80% of the hundreds of thousands of processed food items that are sold contain added sugar.
It’s not about willpower
You may hear that foods are neither good nor bad, that all you need to do is practice moderation.
Yet personal empowerment and responsibility are rarely strong enough defenses against addictive foods. Eating such foods leads to a vicious cycle of cravings. Chemically exaggerating certain flavors can create taste sensations so intoxicatingly appealing that no matter how much you devour, you feel you can never get enough.
You may also hear that you can eat whatever you want and simply “exercise it off.”
But you’d have to walk 4.5 miles to burn off one 20-ounce soda. And you’d have to run 4 miles a day for a week to burn off just one supersized fast-food meal. (And once you’ve eaten it, you’re going to want another — soon.)
And it’s not about moderation
Twelve Step addiction programs don’t advise practicing moderation. They want alcoholics and addicts to completely clear the brain and body of the addictive substance.
Moderation won’t work for food addiction, either.
If you continue to “use” sugar and processed foods, your dopamine receptors will decrease. You will develop tolerance. And you will need more and more of these addictive substances to generate the same amount of pleasure.
The more you’re aware of the biological forces at play in your cravings and how important it is to break free of them, the better your chance of healing yourself.