It’s pretty easy to identify the foods that are addictive. They are the ones that people “can’t stop eating.” This is a circular definition. "Addictive" means that you can’t stop doing something. You can't stop doing it even when you know that you want to stop it, or that it’s harming you.

But what makes addictive foods different from others? Why does a tub of Ben and Jerry’s ice cream or a Krispy Kreme hook you in a way that plain steak or steamed broccoli don’t?

Nobody “can’t stop eating” steak. Yes, you can eat a huge steak when you’re famished. Most people love the taste and enjoy eating steak. But once you feel full, you’re full. When you’re full you don’t feel a powerful urge to eat more and more steak. A lot of foods are like this – especially whole, natural foods. When was the last time you binged on plain, unsalted boiled potatoes or steamed whitefish?

What are the foods that people can’t resist? Chips, pizza, donuts, candy bars, ice cream, pastry, cake, etc. What are the common features of these foods?

• They are energy dense. They are high in calories per gram or ounce.
• They combine carbohydrates and fat in a single food. The carbs may be sugar or starch or both.
• They are low in protein and fiber.
• They contain concentrated energy: refined sugar, flour, and/or concentrated oils and fats.
• They are sweet and/or salty. They have strong natural or artificial flavors that make them pleasurable to eat.

These traits make food addictive. The more of them a food has, the more habit-forming it is.

Food scientists and engineers understand this. They run scientific trials on foods to see which ones people like more. Look at a typical appetizer at a chain restaurant. For example, take the legendary “Bloomin’ Onion” from Outback Steakhouse. It’s breaded (carbs) and deep fried (fat). The onion on the inside and the creamy (fat) dipping sauce are sweet (sugar). The dish is salty and spicy, and the dipping sauce has a smoky flavor with spice as well. It’s a perfect storm of the addictive factors listed above.

This dish is hardly unique. Many, even most, restaurant appetizers combine the above factors. And why shouldn’t they? The restaurant is a business. The restaurant owners want to make customers happy with their meal. and return to spend more money.

High energy density makes foods desirable to the brain at an unconscious level. The starch and sugar digests right away. It provides a quick dopamine hit to the brain. The fat is pleasurable to eat and also signals to the brain that this is a “good” food. These traits make you want to keep eating the food to keep the pleasure flowing.

Low protein and fiber trick the digestive system and brain. They make the natural “stop eating, I’m full” signal take a long time to activate. That means that you can keep eating and never feel satisfied or full. As the potato chip ad says: “betcha can’t eat just one.”

Let’s look at the opposite case: foods that are satisfying but not addictive. Imagine a bodybuilder’s meal of plain grilled chicken breast and steamed broccoli. If you’re very hungry, this meal will taste good and fill you up. The protein in the chicken and the fiber in the broccoli guarantee that. Once you’ve eaten enough, you don’t feel an insatiable urge for more chicken and broccoli.

What are the common features of non-addictive foods? These features are the opposite to their counterparts above.

• They are low-energy per gram or ounce ("low energy density").
• They are high in protein or fiber.
• They are low in fat and digestible carbohydrates.
• They are in or close to their natural state.

When you eat these foods, you get full. When you eat a reasonable serving of low-fat cottage cheese or steamed broccoli, you get full. You don’t crave more of the same. Even when you do overeat a bit, you notice it and stop.

For most of us, the best path to a healthy weight and body composition is whole, natural foods. This is true regardless of your diet pattern and habits.

Some people are able to moderate their consumption of addictive foods. These are the “naturally thin” folks who can enjoy a small taste of a dessert or a single square of dark chocolate.

For everyone else, the solution to addiction is simple: to quit.