Ever feel that a chocolate chip cookie, an order of fries or some other delicious snack has control over you? That you can’t think about anything else until you get the food in your hands and take a bite?

David Kessler, a doctor and former commissioner of the Food and Drug Administration (the government agency that helps assure that what we eat, drink and take as medicine is safe), has felt that way himself. He has been overweight during some of his life, including parts of his childhood, and he was so surprised by his lack of self-control that he researched the science behind his cravings. He believes that it’s the food, not us, that’s to blame.

In his new book for kids and teenagers, “Your Food Is Fooling You,” Kessler shows how food companies have loaded their products with sugar, fat and salt so that customers will keep coming back for more. Using lab science as well as tons of taste tests, companies have figured out how to take advantage of our brains’ positive responses to sugar, fat and salt. Flavor, texture and quantity have been so intensified, Kessler says, that eating has become “a carnival.”

Unfortunately, this carnival is not filled with vitamins and minerals. Before it gets to consumers, food is often drained of its nutrients. For example, in some cases, a single chicken tender has so much batter and fat that Kessler says it could be called a UFO — “an unidentified fried object.” And the fat itself is chock-full of salt and sugar.

Kessler says he once welcomed huge servings and obsessed over certain dishes — fried vegetable dumplings, for example — but he has retrained his brain to desire smaller portions and healthful food. He believes kids can question the food industry just as earlier generations have objected to smoking. “Seven- to 12-year-olds went home and said, ‘Mom and Dad, please don’t smoke.’ Kids now can do something similar rejecting harmful foods.”

Among the steps Kessler recommends — to kids and adults alike — to avoid overeating:

Know what — and when — you’re eating: Find out how much salt, sugar and fat is in your food. You need nourishment every four hours that you are awake. You don’t need round-the-clock snacks.

Don’t supersize it: You don’t need a lot of food or drink to satisfy hunger and thirst. Eat food you enjoy in small amounts.

Take a hike instead of a cookie: Running around triggers the same part of your brain that eating salty, sugary food does. So physical activity can make you feel as if you’ve just eaten dessert!

Kessler knows kids want to be independent, not ruled by their stomachs. “The goal,” he says, “is to be able to make your own choices.”

David Kessler’s book uses science to look at food.

—Abby McGanney Nolan