In his last book, Mr. Pollan summarized his approach in just seven words: “Eat food. Not too much. Mostly plants.” The new book provides the practical steps, starting with advice to avoid “processed concoctions,” no matter what the label may claim (“no trans fats,” “low cholesterol,” “less sugar,” “reduced sodium,” “high in antioxidants” and so forth).

Image Credit... Getty Images

As Mr. Pollan puts it, “If it came from a plant, eat it; if it was made in a plant, don’t.”

Do you already avoid products made with high-fructose corn syrup? Good, but keep in mind, sugar is sugar, and if it is being added to a food that is not normally sweetened, avoid it as well. Note, too, that refined flour is hardly different from sugar once it gets into the body.

Also avoid foods advertised on television, imitation foods and food products that make health claims. No natural food is simply a collection of nutrients, and a processed food stripped of its natural goodness to which nutrients are then added is no bargain for your body.

Those who sell the most healthful foods  vegetables, fruits and whole grains  rarely have a budget to support national advertising. If you shop in a supermarket (and Mr. Pollan suggests that wherever possible, you buy fresh food at farmers’ markets), shop the periphery of the store and avoid the center aisles laden with processed foods. Note, however, that now even the dairy case has been invaded by products like gunked-up yogurts.

Follow this advice, and you will have to follow another of Mr. Pollan’s rules: “Cook.”

“Cooking for yourself,” he writes, “is the only sure way to take back control of your diet from the food scientists and food processors.” Home cooking need not be arduous or very time-consuming, and you can make up time spent at the stove with time saved not visiting doctors or shopping for new clothes to accommodate an expanding girth.

Although the most wholesome eating pattern consists of three leisurely meals a day, and preferably a light meal at night, if you must have snacks, stick to fresh and dried fruits, vegetables and nuts, which are naturally loaded with healthful nutrients. I keep a dish of raisins and walnuts handy to satisfy the urge to nibble between meals. I also take them along for long car trips. Feel free to use the gas-station restroom, but never “get your fuel from the same place your car does,” Mr. Pollan writes.

Treating Treats as Treats

Perhaps the most important rules to put into effect as soon as possible are those aimed at the ever-expanding American waistline. If you eat less, you can afford to pay more for better foods, like plants grown in organically enriched soil and animals that are range-fed.