If we can’t rely on the marketers or the government or even the nutritionists to guide us through the supermarket, then who can we rely on? Well, ask yourself another question: How did humans manage to choose foods and stay healthy before there were nutrition experts and food pyramids or breakfast cereals promising to improve your child’s focus? We relied on culture, which is another way of saying: on the accumulated wisdom of the tribe. (Which is itself another way of saying: on your mom and your grandma.) All of us carry around rules of thumb about eating that have been passed down in our families or plucked from the cultural conversation. Think of this body of food knowledge as samizdat nutrition: an informal, unsanctioned way of negotiating our eating lives that becomes indispensable at a time when official modes of talking about food have suffered a serious loss of credibility.
Here are a few of Michael Pollan’s aphorisms given in his book ‘Food Rules’ that help us navigate today’s supermarkets:
Avoid foods you see advertised on television.
Food marketers are ingenious at turning criticisms of their products—and rules like these—into new ways to sell slightly different versions of the same processed foods: They simply reformulate (to be low-fat, have no HFCS or transfats, or to contain fewer ingredients) and then boast about their implied healthfulness, whether the boast is meaningful or not. The best way to escape these marketing ploys is to tune out the marketing itself, by refusing to buy heavily promoted foods. Only the biggest food manufacturers can afford to advertise their products on television: More than two thirds of food advertising is spent promoting processed foods (and alcohol), so if you avoid products with big ad budgets, you’ll automatically be avoiding edible foodlike substances. As for the 5 percent of food ads that promote whole foods (the prune or walnut growers or the beef ranchers), common sense will, one hopes, keep you from tarring them with the same brush—these are the exceptions that prove the rule.
If it came from a plant, eat it; if it was made in a plant, don’t.
Don’t eat breakfast cereals that change the color of the milk.
This should go without saying. Such cereals are highly processed and full of refined
carbohydrates as well as chemical additives.
Eat all the junk food you want as long as you cook it yourself.
There is nothing wrong with eating sweets, fried foods, pastries, even drinking soda every now and then, but food manufacturers have made eating these formerly expensive and hard-to-make treats so cheap and easy that we’re eating them every day. The french fry did not become America’s most popular vegetable until industry took over the jobs of washing, peeling, cutting, and frying the potatoes—and cleaning up the mess. If you made all the french fries you ate, you would eat them much less often, if only because they’re so much work. The same holds true for fried chicken, chips, cakes, pies, and ice cream. Enjoy these treats as often as you’re willing to prepare them—chances are good it won’t be every day.
Eat when you are hungry, not when you are bored.
For many of us, eating has surprisingly little to do with hunger. We eat out of boredom, for entertainment, to comfort or reward ourselves. Try to be aware of why you’re eating, and ask yourself if you’re really hungry—before you eat and then again along the way. (One old wive’s test: If you’re not hungry enough to eat an apple, then you’re not hungry.) Food is a costly antidepressant.
Do all your eating at a table.
No, a desk is not a table. If we eat while we’re working, or while watching TV or driving, we eat mindlessly—and as a result eat a lot more than we would if we were eating at a table, paying attention to what we’re doing. This phenomenon can be tested (and put to good use): Place a child in front of a television set and place a bowl of fresh vegetables in front of him or her. The child will eat everything in the bowl, often even vegetables that
he or she doesn’t ordinarily touch, without noticing what’s going on. Which suggests an exception to the rule: When eating somewhere other than at a table, stick to fruits and vegetables.
Micropaedia 
I loved reading this book.