It’s a Lifestyle, Not a Diet

Throughout this book, we’ve referred to the vegetarian diet, with the word “diet” being used in its original sense—your overall system of nourishing yourself. As a vegetarian, you’re changing your diet but you’re not on a diet, which is a significant difference. But they both systems focus on one thing: calories. A healthy diet, however, doesn’t involve counting calories and withholding food so the body starves. A healthy diet allows the body ample calories so that every one of its functions like a well-oiled machine, burning fuel as it hums along.

Calories are units of energy, like the gallons of gas you use to fuel your car. You consume calories when you eat, and your body burns the energy to fuel all the things that it needs to do. Whether you’re running around the block or sitting on the couch watching television, your body is burning energy to keep your heart pumping, your lungs and kidneys functioning, your brain working, and your muscles contracting.

The pace at which your body burns calories when at rest is called “basal metabolism.” That’s when you burn most of your calories, actually—during sleeping or just sitting around. You burn them at a faster rate when you’re exercising and digesting food, but your basal metabolism determines how many calories you need to function, with the excess being stored as fat.

As you’re no doubt aware, some people have faster metabolisms, while others have sluggish ones. Men usually have higher metabolisms than women because they have more muscle mass. People who exercise regularly can raise their metabolism, so they burn more calories even when they’re at rest.


Whatever the speed of the metabolism, though, it’s fuel is the calories. Foods that have a lot of calories are loaded with fuel from protein, carbohydrates, and fat. If you eat the same amount of calories that you need to fuel your body, you can maintain your ideal weight. Take in more calories than you burn, and you store the excess calories as fat. Weight loss occurs when you consume less calories than your body needs to burn for energy. When it needs fuel, the body turns to the stored fat and breaks it down into usable energy. You can make this happen on purpose by either exercising and burning a lot of calories, or by eating less.

As you’ll remember from previous chapters, our bodies are amazing evolutionary machines and are designed to survive when there’s no food available. When you drastically cut back on the calories you eat, your body thinks that you’re in danger of starving and slows down your metabolism so that you aren’t burning as much energy. This is why most people on calorie-restrictive diets lose quickly at first and then slow down to a crawl— or plateau, at which point they aren’t losing at all even when they’re hardly eating anything at all.

Many people believe that exercise is the answer to boosting metabolism, but it’s only part of the equation. If you’re eating a very low-calorie diet and exercising a lot, your body is still going to believe that it’s starving, so the weight loss will be very, very slow. That’s not to say that exercise isn’t important; maintaining strong muscles helps you stay active and keeps you burning fat, no matter how slowly. But you still need to eat a moderate number of calories to keep your metabolism functioning well so that your body doesn’t go into starvation mode, and finding the right balance can be frustrating to dieters who want to see big results quickly.


 Not All Calories Are Alike

Despite all the advances in nutritional science, most people still believe that losing weight is merely a matter of eating less food. Even a lot of doctors believe it, and they, of all people, ought to know better! But in truth, many overweight people eat less than thin people, the only difference being they just eat the wrong things.


 Of the three main categories of nutrients—protein, carbohydrates, and fat— it’s the fat that contains the most calories. Protein and carbohydrates contain four calories per gram; a gram of fat, on the other hand, contains nine calories. So while fat is an important nutrient for many reasons—like keeping your hormones regulated, your skin and hair healthy, and giving you a feeling of satiety when you eat—it also provides over twice as many calories as protein and carbs. And what foods are the highest in fat? Animal foods.

Plant foods, though, are rich in complex carbohydrates, so you can eat more food while ingesting less calories; this will make you feel fuller and more satisfied. Naturally, you can gain weight while eating carbohydrate- rich foods; remember that excess calories, no matter what their source, are stored as body fat. But studies have shown that, while people eating low- fat, high-carb diets consume more than people on higher fat diets, they’re taking in less calories! In a study at Cornell University, people choosing a diet restricting their fat intake of 20 to 25 percent of their calories ate more food than the subjects choosing a diet of 35 to 40 percent fat, but they never ingested as many calories as the high-fat group.

But there’s more to the story than just calories. While doctors and nutritionalists have always advised that dieting is strictly a lower-your- calories endeavor, current research is revealing that it’s far more complicated than that. The way the body uses the calories from protein, carbs, and fat varies depending on the source of those calories. The human body is designed to store energy from fats and proteins while it burns carbs for immediate energy. We’re just not meant to store carbohydrates; for every one hundred calories that you eat, twenty-three are burned just converting the carbs to usable energy! The fat we eat is a double whammy; not only are there more calories per gram of fat, only three of every one hundred calories are burned during conversion, meaning that it’s later to burn as energy and stored as excess body fat more easily.

The nature of carbohydrates is that they’re the first type of energy that our body turns to, which makes it actually difficult to store carbs as fat. In a
1991 clinical study, only 2 percent of the calories eaten by subjects were converted into fat. So while calories are important, it’s the fat calories that are best cut back on.


 It’s also possible to lose weight on a high-protein, low-fat diet, but there are reasons why that is a bad idea. For one thing, it isn’t easy.The whole foods highest in protein are animal foods, so they’re also high in fat. Perhaps you’ve tried one of these diets in the past and discovered that eating scrambled egg whites, skinless chicken breasts, and dry, broiled fish gets boring very quickly. But another reason to steer clear of high-protein diets is the difficulty, discussed in an earlier chapter, that your body has processing protein. Too much protein overtaxes your kidneys, and it builds calcium deposits in your bones and urinary tract. So the best overall weight-loss plan is one that gives you energy from healthy, complex carbohydrates derived from plant sources.