They may have salt, sugar, and fat on their side, but we, ultimately, have the power to make choices. After all, we decide what to buy. We decide how much to eat.

Science is starting to show that our brains are less able to detect calories in liquids. So, people in the know, including food industry executives, when they run into health trouble, the first thing they do is cut calories out of all the liquids that they drink as a way of maintaining their weight.

As a culture, we've become upset by the tobacco companies advertising to children, but we sit idly by while the food companies do the very same thing. And we could make a claim that the toll taken on the public health by a poor diet rivals that taken by tobacco.

They may have salt, sugar, and fat on their side, but we, ultimately, have the power to make choices. After all, we decide what to buy. We decide how much to eat.

What I found, over four years of research and reporting, was a conscious effort — taking place in labs and marketing meetings and grocery-store aisles — to get people hooked on foods that are convenient and inexpensive.

Health messages are simply overwhelmed, in volume and in effectiveness, by junk-food ads that often deploy celebrities or cartoon characters to great effect. We may know that eating fruits and vegetables is good for us, but the preponderance of the signals we get - and especially the signals children get - push us in the direction of junk food.

Each year, food companies use an amount of salt that is every bit as staggering as it sounds: 5 billion pounds.