Former United States Food and Drug Administration Commissioner David Kessler recently gave an interview to National Public Radio about his new book, "The End of Overeating: Taking Control of the Insatiable American Appetite." During an interview with NPR's Michelle Norris, Kessler answered the big, greasy, salty, sweet 'n' sour question that has been plaguing Americans for years: Why do so many of us feel compelled to overeat? Let me summarize his answer for you.

There are many reasons why people overeat. However, most restaurant food and processed food is even richer in calories and more loaded with fat, sugar and salt than most people realize. Kessler also points out that the ingredients by themselves may not be harmful, but when combined with other ingredients and marketing campaigns, they stimulate millions of Americans. Instinctively, we are drawn to calorie-rich foods and to doing things together with our peers. Marketers know this.

As Kessler explains it, "I give you a package of sugar and I say, 'Go have a good time.' You're going to look at me and say, 'What are you talking about?' Now to that sugar I add fat, I add texture ... I add color, I add temperature, I add the emotional gloss of advertising. I put it on every corner and I tell you, 'You can do it with your friends.' So what's happening for millions of Americans ... they get bombarded with foods. Their brains get activated. No one's explained to them that they are constantly being stimulated."

However, this is no longer merely an American issue. McDonald's is the largest chain of fast food restaurants in the world, with a total of more than 31,000 outlets worldwide. KFC has 11,000 outlets in 80 different countries, so we all need to be aware of what we are eating.

Did you know that it is possible to create virtually any taste sensation with chemicals? In his book, Kessler writes that a cheap piece of meat can be made to taste like it has been seared, braised, roasted or grilled. And, he told Norris, because most of the food that consumers eat today is so appealing to our taste buds.

"Pick an appetizer. What's in Buffalo wings? You start with the fatty part of the chicken. Many times it's fried in the manufacturing plant first. It's fried again in the restaurant. That red sauce? Sugar and fat. That creamy sauce? Fat and salt. So what are we eating? Fat on fat on fat on sugar on fat and salt," Kessler explains.

Kessler says that, by careful design, food is excessively activating the brains of millions of Americans to get them to come back to eat more and more and more. Is there a solution?  Fortunately, knowledge is power. Once you know how a magician achieves an illusion, it ceases to startle you. Likewise, "once you understand you are being stimulated, then you can begin to fight back to prevent being manipulated," says Kessler.

Nutrition is a personal matter. Your nutrition needs to suit your body. How well you eat can determine how you look, act, and feel; whether you can think clearly. The foods you eat can make the difference between your day ending with freshness which lets you enjoy a delightful evening or with exhaustion that leaves you collapsing on the sofal or heading to bed early with a headache. Nutrition is the study of how foods, after they are swallowed, make you tick. Sadly, nutrition is rarely considered by corporations that have their own commercial interests, rather than their customers' nutrition at heart. To this day, most readilly available information about food comes from product advertising. Highly refined foods and hydrogenated oils keep better than natural foods, and thus have longer shelf-lives and cost less. They are cheaper and easier to store and ship. They don't spoil because they cannot support the health of bacteria, fungi, molds, or bugs. However, they frequently can't support the health of humans, either, so why would you eat them?