March is National Nutrition Month. Crack out the frosted Ho Hos, and let's give a cheer. We are what we eat! Why can't I cheat? Must have a treat! Allergic to wheat!

Dear readers, it's a minefield out there. The No. 5 how-to book on the New York Times best-seller list is "The Carb Lovers Diet," a weight-loss program pegged to pasta, potatoes and bread. A few slots down we find Gary Taubes' anti-pasta polemic, "Why We Get Fat," a science-driven indictment of carbs as the cause of all human fat and misery.

Are veggies our friends or our enemies? Is weight loss all about "calories in, calories out," or is that just another unsettling example of nutritional science gone bad?

Bottom line, there's a glut of conflicting and confusing information about the smartest and best diet, which — in my view, and my mother's — turns out to be no diet at all. Don't diet ... just change the way you eat.

Eat (real) food. Mostly plants. Not too much. That's the mighty mantra behind Michael Pollan's classic "Food Rules" (Penguin), a small book that can have a huge impact on your life and your poundage if you're willing to swallow whole the thoughtful guidelines he presents.

First and foremost, fact No. 1: The so-called Western diet (that most Americans eat) makes us sick. Eating lots of processed foods and meat, lots of added fat and sugar, lots of refined grains and very few vegetables, fruits and whole grains puts us at high risk for the so-called Western diseases: obesity, type 2 diabetes and cancer, to name a few.

"Eighty percent of all cardiovascular disease and more than a third of all cancers can be linked to this diet," says Pollan. Oye.

What I appreciate most about "Food Rules" is how simple and straightforward it is. Pollan has stripped away all the hard science, the biochemistry, the thermodynamically complex descriptions of insulin and fat metabolism, and left us with 64 rules that are fun to read and easy to digest, even for children. Here's a sampling, just to whet your appetite for the real thing:

— Rule no. 1: "Eat food." Every year, about 17,000 new products show up on grocery shelves, and most of them are so anti-health they shouldn't even be called food. Pollan calls them "edible food-like substances" and "industrial novelties." Avoid them, and watch how much better you feel.

— "Avoid food products containing ingredients that no ordinary human would keep in the pantry." When was the last time you ran to the store for another batch of ammonium sulfate? Or ethoxylated diglycerides? These additives are there to prolong shelf life, not your life. Stay away. Another one of my favorite Food Rules, a second cousin to this one, is, "Avoid food products containing ingredients that a third-grader can't pronounce."

— "Avoid foods that have some form of sugar (or sweetener) listed among the top three ingredients." Pollan's rules allow for an occasional treat, but in general, it's best to limit your intake of sugar. This is tricky because there are some 40 types of sugar used in processed food. Don't think that fake sugar is OK. It's not, and can really mess up your God-given ability to lose weight.

— "Avoid foods that are pretending to be something they are not." Imitation butter, imitation (non-fat) cream cheese, soy-based mock meats ...n o, no and no.

— "If it came from a plant, eat it; if it was made in a plant, don't."

— "It's not food if it arrived through the window of your car."

— "The whiter the bread, the sooner you'll be dead."

— "Eat animals that have themselves eaten well." Cheap meat and poultry raised and tortured in factory farms should be avoided. Pastured cows and free-range chickens cost more, it's true, but what price do you put on your health? This leads to another one of Pollan's precepts: "Pay more, eat less."

— "Don't eat breakfast cereals that change the color of your milk." Why? Because those are the cereals that are highly processed and full of refined carbohydrates and chemical additives.

— "Stop eating before you're full."

— "Spend as much time enjoying the meal as it took to prepare it."

Don't stop now. Go get your own copy of "Food Rules," and keep reading it until your life changes.

ENERGY EXPRESS-O! I'LL DRINK TO THAT

"Rule No. 43: Have a glass of wine with dinner." — Michael Pollan

Marilynn Preston — fitness expert, personal trainer and speaker on healthy lifestyle issues — is the creator of Energy Express, the longest-running syndicated fitness column in the country. She has a website, http://marilynnpreston.com and welcomes reader questions, which can be sent to MyEnergyExpress@aol.com. To find out more about Preston and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.