Are Your Instincts Making You Fat?


By Shaun Chavis

Can't resist those Krispy Kremes in the break room? Don't blame your lack of self-control. Good old-fashioned willpower doesn't work, according to the book The Instinct Diet">The Instinct Diet by Susan Roberts, PhD, a professor of nutrition and psychiatry at Tufts University. Instead, what we eat is governed by five instincts developed by evolution and survival. Though her ideas seem controversial, Roberts' research at Tufts got big results: 85% of dieters lost 10 to 50 pounds, and 90% of those dieters kept the weight off for at least a year. Here, Roberts breaks down her theories and suggests easy ways to make them work for you.

Willpower is useless
The science: Food instincts are controlled mostly out of the unconscious parts of our brain. They are similar to breathing in many ways—so important to our long-term safety that they are largely unconscious processes. Willpower is fairly useless when it comes to our food instincts, because it is the conscious control of conscious processes. Willpower doesn't speak to the unconscious processes at all! I think most psychologists have it backward, really, and their attempts to get people to be tougher and put up with more hardship are attacking weight problems from the wrong end.

The strategy: To confront weight problems from a different direction, use willpower to make conscious decisions. For example, you can decide whether to eat out or stay in, but after you have eaten the first piece of bread from the restaurant breadbasket, your instincts take over and make you eat several pieces until you are satisfied.

If you want to change how and what you eat, you have to control the signals to your brain
The science: Many weight-loss strategies are designed to control food instincts after they have been activated (such as eating your chips mindfully after they have already set off dopamine-addiction chemicals). What we need to do for long-term success is reduce the need for willpower by avoiding activating our instincts in the wrong way in the first place.

The strategy: Start by becoming familiar with your five basic instincts regarding food. Here's a quick rundown:

  • The Hunger Instinct: We need to feel full.
  • The Availability Instinct: If food's there, we're going to eat it.
  • The Calorie-Density Instinct: The more calories a food has, the more we like it.
  • The Familiarity Instinct: We're driven to eat foods we already know, and we're driven to eat similar foods in familiar emotional situations.
  • The Variety Instinct: The more choices we have, the more we eat.

Next: Outsmart your instincts

Outsmart your instincts
The science: As an example, let's take the Variety Instinct (the more choices we have, the more we eat). This instinct is key to human survival: No one food contains all the nutrients we need, so we're driven to eat a wide variety (even fish are influenced by variety and eat more if they have more choices). But if you're faced with a variety of the wrong kinds of foods, you'll overeat.

The strategy: Eating a wide variety of foods doesn't mean you have to eat more calories. Satisfy your variety instinct by increasing the number of low-calorie, healthy foods—like leafy greens or antioxidant-rich berries—and cutting back on the rest. Before your weekly shopping trip, decide what you will eat for the week. You'll have healthy options at your fingertips (and no excuse to get takeout). And there's nothing wrong with including some ready-made salads and other prepared things, of course. Eat salads for several days at the beginning of the week when they are fresh, and then move on to fresh or frozen veggies. Don't feel bad about eating the same veggies two days running—just try to buy a new vegetable each time you shop.

Exercise doesn't do a lot to help you lose weight
The science: The average results for exercise intervention are trivial. The changes in body fat are so tiny that I thought it was important to call a spade a spade here. Exercise is important for health, and important for keeping weight off once you have lost it, but it doesn't help weight loss that much.

The strategy: If someone exercises like crazy to lose weight and it doesn't work, that person will blame herself. I'm trying to reduce the blame, because it's not anybody's fault. Instead, focus on the importance of food.

Instinct or willpower? What do you think of Dr. Roberts' approach?