Read Food for Life: How the New Four Food Groups Can Save Your Life Online
Authors: M. D. Neal Barnard
Tags: #Health & Fitness, #Diet & Nutrition, #Nutrition, #Diets
Something similar happens with another hormone called
norepinephrine
, a relative of adrenaline. As carbohydrate-rich foods gradually release sugars into the body, more norepinephrine is produced, and it too encourages faster metabolism. Cigarettes do the same thing, which may be one reason why smokers are sometimes leaner. In an interesting experiment, researchers found that carbohydrate increases norepinephrine about the same amount as do cigarettes.
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The moral of the story is not to have a cigarette, but rather to boost the carbohydrates in your diet. Vegetables, grains, fruits, and beans provide generous amounts of complex carbohydrates. In addition, fruits and vegetables are rich in potassium, which has been shown to boost the metabolism.
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Another important role of carbohydrates is that they are part of the cuing mechanism that tells the body when it has had enough food. Did you ever wonder why you stop eating? It is not just because your stomach is full. If it were, a few glasses of water would eliminate your appetite. It is also not the amount of fat in foods. If more fat were slipped into your foods, you would not find yourself responding by eating less; in fact, if you kept this up, the bathroom scale would register a bit more weight.
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Carbohydrates are the cue the body needs to stop eating. The body adjusts the appetite based on the carbohydrate content of the meals you eat. So you will eat more if there is little carbohydrate on your plate and less if there is a lot there.
Calories in Nutrients
(per gram)
Carbohydrate | 4 |
Protein | 4 |
Fat | 9 |
Fruits contain a natural sugar called
fructose
, which may also play a role in the cuing process. Researchers found that when people consume a test dose of fructose, their appetites diminish.
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In particular, they eat less fatty foods. It may well be that one way to cut your appetite for fatty foods is to bring home more fruit from the produce department. When you have a hankering for dessert, eat an apple, an orange, a pear, or a bowl of mixed fruit.
As we have noted, complex carbohydrates are found only in plants. Grains, vegetables, and beans are loaded with them, but there is virtually no complex carbohydrate in fish, chicken, beef, milk, or eggs. Along with carbohydrate, plants also supply fiber, which contains almost no calories, but adds texture to foods and makes them satisfying. Fiber is the part of plants that resists digestion in the small intestine—what people used to call roughage. The value of fiber was not appreciated until relatively recently, and so it was discarded in the process of refining whole-grain flour for white bread, and brown rice into white rice. Now we know that leaving the fiber in foods makes them more satisfying yet lower in calories.
To the extent that animal products or refined foods are included in the American diet, the fiber content of our foods is reduced. A healthful diet includes 30 to 40 grams of fiber each day. Yet Americans get only about half that because of their penchant for animal products and refined plant foods. When you build your menu from high-carbohydrate foods such as whole grains, beans, and vegetables, the fiber content of your diet will increase naturally.
Table 8
Plant Products vs. Animal Products
High-Fat Plants
Nearly all foods from plants are low in fat. But the following are high in fat. Even though the fat is mostly unsaturated, it is more than you need. Figures are percentages of calories.
| Fat | Carbohydrate |
Avocado | 66 | 29 |
Cashews | 73 | 23 |
Green olives | 92 | 4 |
Sunflower seeds | 77 | 13 |
Tofo | 54 | 12 |
What are the most fattening foods? Meats, most dairy products, fried foods, vegetable oils, and salad dressings. What do these all have in common? They are loaded with fat, and fat is easily the most fattening part of the diet.
All fats and oils are extremely high in calories—9 calories in every gram. And fat in foods adds very easily to your fat stores. If you eat fat (animal fat or vegetable oil), it is added to your body fat with a loss of only about 3 percent of its calories in the process.
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In contrast, if the body tries to store the energy of carbohydrates, it has to chemically convert it to fat, a process which consumes 23 percent of its calories. As an example, let’s compare rice versus chicken. A ½-cup serving of rice holds 100 calories of carbohydrate. If the body tries to convert it into body fat, nearly a fourth of its calories are burned up and lost in the process. The rice contains almost no fat, only one-tenth of a gram. On the other hand, a chicken breast holds no carbohydrate at all. And nearly all the chicken fat can easily add to the fat on your body. If you were to eat two-thirds of a whole breast, you would have gotten 100 calories worth of chicken fat, only three of which are lost if it is converted to body fat. So not only are fats naturally high in calories; the calories from fat are more likely to increase body fat than are the same number of calories from carbohydrates.
To make matters worse, fatty foods have no metabolism-boosting effect. Researchers have put volunteers into experimental chambers that precisely measure how much oxygen they breathe in, how much carbon dioxide they breathe out, and how much heat their bodies generate. They have kept them in these chambers for days on end, feeding them different kinds of foods and measuring whether their metabolic rates increase or decrease. Although carbohydrates clearly boost the metabolism, fats do not.
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A fatty meal causes no particular “burn.” Part of the fat you eat is used up, and part is added to the fat stores you already have.
There are various kinds of fat. As mentioned in
Chapter 2
, the main categories of fat are saturated and unsaturated fat. Different kinds of fat have different effects on cholesterol levels. But for
weight control
, we need to be concerned about
all
forms of fat. As far as your waistline is concerned, animal fat is no better or worse than vegetable oil. Let’s look at both.
Animal fat is an obvious problem. It was designed by nature specifically to store calories. The fat in beef, pork, chicken, or fish is the calorie-storage area of that animal. So if you eat animal fat, you are eating all those densely packed calories.
Many people have the misconception that if they trim the fat off the outside of a piece of meat, they have got rid of its fat. But because meats contain virtually no carbohydrate and no fiber, their main nutrients are protein and fat. Imagine that you took a sponge and poured oil into it, soaking the sponge with grease. Now, if you were to take one paper towel after another and wipe off the surface of the sponge, you would remove some grease, but the sponge would still be saturated with it. This is about what happens when people try to trim the fat from meats. You can remove some of the external fat, but it is impossible to remove the fat that permeates the cut of meat. If you are eating meat, you are eating another animal’s fat and another animal’s stored calories. Let’s take some examples. For comparison, potatoes and rice are each about 1 percent fat; legumes such as peas or beans are only 3 to 4 percent fat; and most other vegetables tend to range between 5 and 10 percent fat (as a percentage of calories). In contrast, ground beef is about 60 percent fat. “Extra-lean” ground beef is not really so lean: 54 percent of its calories are from fat. Even the skinniest six beef specimens selected for the beef industry’s “lean” advertisements could not find any cuts of meat that are anywhere near the fat content of beans, grains, or vegetables: round tip is 36 percent fat, top loin is 40 percent fat, top round is 29 percent fat. At its lowest, beef is still around 30 percent fat, which is several times the fat content of grains, vegetables, beans, and fruits. “Lean meat” is a contradiction in terms.
In the kitchen, the difference is even more obvious. Let’s say we are making tacos using two different recipes for taco filling—one is made with ground beef and the other with beans. Three ounces of ground beef have about 225 calories. Beans, on the other hand, are very low in fat, and so three ounces of cooked beans have only about 110 calories. Which recipe do you follow to lose weight? And when you are eating out, any taco restaurant in the country will gladly substitute a bean filling for a meat one. It’s cheaper for them, and it’s better for you.
Let’s say you are preparing a spaghetti dinner. A 1-cup serving of spaghetti topped with ½ cup of tomato sauce has about 200 calories. But if we add ground beef to the sauce, the dinner now has 365 calories. The ground beef has no carbohydrate at all and lots of fat, so it contributes a lot of calories.
The animal fat in dairy products is a big calorie booster, too. Look at what a little butter can do. A 1-cup serving of mashed potatoes made without butter or milk has 140 calories. Add a tablespoon of butter and what happens? Suddenly it holds nearly 250 calories.
Chicken producers have hoped that consumers would reject beef and choose their products instead. But chicken is no health food. The worst of the lot is the chicken frank, which weighs in at 68 percent fat. Roast chicken is 51 percent fat. Well, you may be asking, how about if I strip off the skin, throw away the dark meat, and use a nonfat cooking method? Even then, chicken is still 23 percent fat (plus 85 mg cholesterol in a 3.5 oz. serving), which is much higher than most grains, vegetables, fruits, and beans. The point is that chicken is much more like beef than it is like vegetables. It contains no carbohydrate or fiber, and it pushes these foods off your plate. As far as weight control is concerned, no matter how it is prepared, chicken lacks the power of a truly healthful food.
Fish has gotten more attention recently, particularly in discussions about cholesterol. But as far as your weight is concerned, fish fat is like any other fat: it contains 9 calories per gram. Of course, different types of fish differ greatly in fat content, ranging from high-fat varieties like salmon, to varieties like sole or haddock, which are similar to vegetables in fat content. That is their only similarity to vegetables, however. In all other; respects, sole and haddock are typical animal muscles: no complex carbohydrates, no fiber, and a tendency to displace these foods from the diet. Plus, they contain significant amounts of cholesterol, far too much protein, and for many varieties serious contamination problems. So fish is not a health food, although certain types of fish are much lower in fat than are beef and poultry.
In summary, meats, poultry, and fish have two main problems for those concerned about their weight. First, they are muscles, and muscles are made up of protein and fat. Second, they contain no fiber at all and virtually no carbohydrate. So they not only give you a load of fat you don’t want but also displace the fiber and carbohydrates that are essential to a satisfying and metabolism-boosting menu. Vegetarian foods—grains, vegetables, fruits, and legumes—are power foods for weight control.
In their defense, vegetable oils have no cholesterol and most are low in saturated fats compared to animal fats. But their calorie content is the same as any other kind of fat: 9 calories in every gram. All fats and oils are packed with calories, and it is no good becoming a vegetarian if meats are replaced with french fries.
Let’s take an example. Only about 1 percent of the calories in a potato is from fat. And if it is baked or mashed, no extra oil is added. But let’s say we cut a potato into french fries and drop it into some hot oil. Its fat content soars to 40 percent or more, while its calorie content doubles or even triples.
Here’s another example. Doughnuts are fried and bagels are not. Which do you think have more fat? No contest. Half the calories in the doughnut are from fat, while the bagel’s calories are only 8 percent from fat. Of course, if you add cream cheese or margarine to the bagel, the fat and calorie content quickly climbs.
Baked goods can be either very low or very high in fat. Bagels, pretzels, and many breads are quite low. On the other hand, croissants, cakes, pies, and cookies are usually loaded with fat. If you are baking, it is often easy to modify recipes, as we will see in
Chapter 8
. If you are buying commercial baked goods, check the label. Fat content is usually listed.
Tips for interpreting labels are given. If the fat content is not specifically listed, check the ingredients. These are listed in decreasing order of quantity, so if oil is one of the first ingredients, there is more of it than if it is one of the last items. The nutrition information label from a bag of potato chips is shown. What is important is the
percentage of calories
that comes from fat. This is easy to check. The top line of the label shows that there are 260 calories in one serving. Next to this, we see that 140 of these calories come from fat. To calculate the percentage, we simply divide the calories from fat by the total calories and then multiply by 100.