To understand why this program is the most powerful form of medicine, you must start with the recognition that plant foods are the most abundant sources of nutrition on earth. Animal foods don't even come close in comparison. And, despite what you've been told, animal foods are not essential sources of minerals, calcium, protein, amino acids, vitamins or essential fats.
Nutrients are, essentially, the raw materials your body needs to function properly and to grow. In general, there are two types of nutrients – the ones your body can make, and the ones it can derive only from your food. The latter are called "essential" nutrients, for the simple fact that your diet must provide them for you to sustain your health.
There are 13 essential vitamins. Eleven are made in abundance by plants. The two that are not produced by plants are vitamins D and B12. You should get all the vitamin D you need from sunlight – and B12 can be gotten from a supplement. (I tell pregnant and nursing women, and people following my diet strictly for more than 3 years, to take five micrograms of vitamin B12 each day to ensure that they are getting an adequate supply of the vitamin.) Both vitamins are stored in your tissues for long periods of time.
Animal foods have little nutritional value
There's no comparison between animal foods and plant foods when it comes to providing the immune-boosting and cancer-fighting substances, beginning with the antioxidant vitamins C, E, and beta carotene. Animal foods are either exceedingly low or devoid of the antioxidants. Also, plant foods provide a wide spectrum of vitamins, minerals, and other health-promoting substances, while animal foods tend to offer concentrated amounts of individual nutrients, such as protein or calcium, while being deficient in many others.
Only plants contain powerful substances called phytochemicals, which scientists are now discovering protect us from cancer, heart disease, and an array of other serious illnesses.
Plants are also the primary source of all minerals in the diet. In fact, all minerals are derived originally from the earth and make their way into the food supply via plants. The only reason animal foods contain any minerals at all is because the animals eat plants, or they eat animals that eat plants.
Plants are also the only sources of fiber, which binds in your intestines with fat, cholesterol, environmental pollutants, and disease-causing hormones and eliminates these dangers from the body. Fiber also
decreases intestinal transit time and promotes healthy bowel elimination. As I will show below, fiber is one of the key substances that protect us from cancer, especially from cancers of the large intestine and breast.
All the protein you need – without the meat
Protein is one of the most misunderstood and, consequently, most abused substances in the food supply. First, you should know that all plant foods contain protein. Indeed, all the protein you need and more can be easily derived from plant foods alone.
Second, all plant foods contain "complete proteins," meaning that they contain all the "essential" amino acids, which are the building blocks of proteins. This means that you will get all the protein – as well as all the amino acids – you need on a diet composed exclusively of plant foods. Think about it. Plants are the only foods eaten by elephants, horses, and hippos, and all three have no trouble growing all the muscle, bone, and tissue they need. Surely, there's enough protein in plant foods to grow a human being, especially since we are relatively small when compared to an elephant.
To be on the safe side, the World Health Organization (WHO) recommends men, women, and children should get five percent of their calories from protein. WHO recommends pregnant women should get six percent. The chart to the right reveals the protein levels of selected plant foods. As you will see, it's virtually impossible to fail to meet the World Health Organization's daily requirements.
Americans are getting too much protein
The truth is, Americans consume six-to-10 times as much protein as they need. That excess protein overworks the liver and kidneys, causing both these organs to become enlarged and injured. Excess protein consumption causes the kidneys to pull large quantities of calcium from the body, causing bones to weaken and kidney stones to form.
Scientists have found that animal proteins are particularly damaging to the body, because so many of their amino acids contain sulfa, which is far more toxic to the liver and kidneys than vegetable proteins. One of the most time-honored approaches to healing the kidneys and liver, in fact, is to eat a low-protein diet, especially a diet low in animal proteins. When the protein content of the diet drops, kidneys are strengthened and very often healed.
Americans have always had a love affair with animal protein - an affair that, unfortunately, is making us sick.
What the world needs now is carbohydrates - and lots of them
Carbohydrates are our primary source of energy. They alone provide energy for red blood cells, and certain cells of the kidneys, and the preferred fuel for the central nervous system, including the brain. Fat, on the other hand, is a secondary source of energy that can be used by some tissues, such as muscle, but is more often stored for use in times of famine.
Humans were designed by nature to crave carbohydrates - or, to put the matter in more practical terms, to crave sweet-tasting foods. Because of the sweet-tasting taste buds are on the tip of our tongues we are designed to seek starches, vegetables and fruits - which supply us with both energy and maximum nutrition. In fact, carbohydrates, with their unique combination of sweet-flavor, energy, and nutrition, regulate our hunger drive. Unless you eat enough carbohydrate foods, you will remain hungry and looking for food.
There are no carbohydrates in red meat, poultry, fish, shellfish, or eggs. Most dairy products are deficient in carbohydrates. Cheese, for example, contains only two percent carbohydrate. This is one important reason people who eat a diet rich in animal foods never satisfied and become compulsive overeaters.
Unprocessed plant foods, such as brown rice, potatoes, squash, broccoli, and apples - just to name a few - are loaded with carbohydrates. In fact, they provide an abundance of complex carbohydrates, which are long chains of sugars that are harmoniously mixed with other plant materials. These long chains must be broken down inside your intestine before they can be used as fuel. The process of digesting these complex sugars is slow and methodical, providing a steady stream of fuel pumped into your bloodstream as long-lasting energy.
On the McDougall diet, between 70 and 90 percent of your calories are derived from complex carbohydrates, which is why people on my program experience high levels of vitality and endurance. Recall that all winning endurance athletes carbohydrate-load, not just before the race, but all year long.