Bread, rolls, crackers Bread, rolls, crackers .

8.7 8.7.

4.

Mixed dishes Mixed dishes .

8.2 8.2.

5.

Dairy Dairy .

7.3 7.3.

6.

Soft drinks Soft drinks .

7.1 7.1.

7.

Vegetables Vegetables .

6.1 6.1.

8.

Chicken, fish Chicken, fish .

5.7 5.7.

9.

Alcoholic beverages Alcoholic beverages .

4.4 4.4.

10.

Fruit, juice Fruit, juice .

3.9 3.9.

For the most part, these foods contain far more calories than are justified by their nutrient levels. In part, this is because they're largely made from corn, in the form of a sugar called high fructose corn syrup; soy in the form of extracted protein or oil; or refined wheat-white flour-all processed to the point where they're nutritionally worthless or even damaging. Furthermore, they often contain added ingredients like preservatives and other chemicals that are at best useless and may be harmful. (Not coincidentally, corn, soy, and wheat are among our most highly subsidized and environmentally damaging crops.

Consider the difference between eating a whole baked potato and eating an individual bag of potato chips. You'd need to eat 2.5 ounces of potato chips (that's two and a half single-serving bags, less than what most people eat in a sitting) to get the protein in one medium baked potato. By then you would have consumed nearly 25 grams of fat and 380 calories; nearly twice the amount in the baked potato, even with a pat of b.u.t.ter even with a pat of b.u.t.ter.

Two Forms of Potato

Nutrient .

Potato Chips (2.5 ounces) Potato Chips (2.5 ounces) .

Medium Baked Potato with Pat of b.u.t.ter Medium Baked Potato with Pat of b.u.t.ter Calories .

380 380.

204 204.

Fat .

25 g 25 g .

4 g 4 g Sugar .

0 g 0 g .

2 g 2 g Protein .

5 g 5 g .

5 g 5 g Fiber .

4 g 4 g .

4 g 4 g Vitamin C .

22 mg 22 mg .

22 mg 22 mg Folate .

33 mcg 33 mcg .

45 mcg 45 mcg Pota.s.sium .

903 mcg 903 mcg .

953 mcg 953 mcg

The environmental impact of overconsumption Even the most conscientious agriculture has some environmental impact, and though much food production yields greenhouse gases, raising livestock has a much higher potential for global warming than crop farming. For example: To produce one calorie of corn takes 2.2 calories of fossil fuel. For beef the number is 40: it requires 40 calories to produce one calorie of beef protein. it requires 40 calories to produce one calorie of beef protein.

In other words, if you grow corn and eat it, you expend 2.2 calories of energy in order to eat one of protein. But if you process that corn, and feed it to a steer, and take into account all the other needs that steer has through its lifetime-land use, chemical fertilizers (largely petroleumbased), pesticides, machinery, transport, drugs, water, and so on-you're responsible for 40 calories of energy to get that same calorie of protein. According to one estimate, a typical steer consumes the equivalent of 135 gallons of gasoline in his lifetime, enough for even some gas guzzlers to drive more than halfway from New York to Los Angeles, or for an energy-efficient car to make the drive back and forth twice. Or try to imagine each cow on the planet consuming almost seven barrels of crude oil.

40 CALORIES of fossil fuel are required to produce 1 calorie of beef protein. CALORIES of fossil fuel are required to produce 1 calorie of beef protein.

Another way to put it is that eating a typical family-of-four steak dinner is the rough equivalent, energy-wise, of driving around in an SUV for three hours while leaving all the lights on at home. In all, the average American meat eater is responsible for one and a half tons more CO2-equivalent greenhouse gas-enough to fill a large house-than someone who eats no meat. If we each ate the equivalent of three fewer cheeseburgers a week, we'd cancel out the effects of all the SUVs in the country. Not bad.

Yet thanks to agricultural subsidies and the lack of regulation about how meat is raised, it's far less expensive than it actually should be.

Because it's more difficult to get at the raw data, it's not as easy (or as much fun) to make similar statements about junk food. But when you add in all the packaging required to get the stuff into supermarkets and fast-food restaurants, the environmental damage is impressive enough. One estimate is that the food industry accounts for 10 percent of all fossil fuel used in the United States; of this, the total energy expended by processing, packaging, and transportation of food products is 37 percent.

To give you an idea of how much more energy goes into junk food than comes out, consider that a 12-ounce can of diet soda-containing just 1 calorie-requires 2,200 calories to produce, about 70 percent of which is in production of the aluminum can. Almost as impressive is that it takes more than 1,600 calories to produce a 16-ounce gla.s.s jar, and more than 2,100 to produce a half-gallon plastic milk container. As for your bottled water? A 1-quart polyethylene bottle requires more than 2,400 calories to produce.

Overproduction drives overconsumption, which in turn is bad for our bodies and the environment-but these negative effects can be diminished by more moderate consumption, which in turn will eventually lead to lower production. This is where we come in: Every time you drink a gla.s.s of tap water instead of bottled water, you save the calorie equivalent of a day's food: the 2,400 calories it takes to produce that plastic bottle.

Likewise, every time you eat a salad instead of a burger you save energy. Look at it this way: When you eat a quarter pound of beef, you're consuming about 20 percent of your daily calories, but it takes about 1,000 calories-almost half your daily intake-to produce that burger. Remember, beef production requires energy for processing, transportation, marketing, and, most of all, the production of all the grain fed to the cow in the first place. (Producing a salad requires energy too, but nothing like what it takes to make that quarter-pounder.) Whenever you eat what might be called inefficient food-and beef is among the leaders in this category-you're consuming more of the planet's energy than you need to live well.

2,200 CALORIES are required to produce a CALORIES are required to produce a 12 12 oz. can of diet soda. oz. can of diet soda.

To make the case for changing your diet even more compelling, consider this: For a family that usually drives a car 12,000 miles a year, switching from eating red meat and dairy to chicken, fish, and eggs just one day a week-in terms of greenhouse gas emissions-is the equivalent of driving 760 miles less a year. And if you switch to a vegetable-based diet for that one day a week, you reduce emissions even more, to the equivalent of driving 1,160 miles less.

And this impact is exponential: By moving totally away from red meat and dairy to a diet made up of chicken, fish, and eggs you reduce your emissions by a further 5,340 miles a year. And if you switch to a completely vegetable-based diet? That same family reduces its emissions by more than 60 percent; the same as cutting their mileage down from 12,000 to just 3,900 miles a year.

Those are simple steps. But if, as is expected, the global population grows by nearly half in the next 40 years, meat consumption would have to fall to about three ounces a day (less than half of what Americans average now) just to stabilize the amount of greenhouse gases produced by raising livestock.

Meat consumption would have to fall 3 3 oz. A DAY to stabilize greenhouse ga.s.ses produced by livestock. oz. A DAY to stabilize greenhouse ga.s.ses produced by livestock.

And stabilizing production isn't going to cut it, since even at current levels global warming is deadly. But since our consumption of energy would also have to be cut back, let's take this as a goal.

The choice is obvious: To reduce our impact on the environment, we should depend on foods that require little or no processing, packaging, or transportation, and those that efficiently convert the energy required to raise them into nutritional calories to sustain human beings. And as you might have guessed, that means we should be increasing our reliance on whole foods, mostly plants.

But before we move forward, let's take a look back to how we got to this place.