Throughout this membership area, we'll be using several terms from basic nutrition. This background information will help you understand our tools, ideas and programs a little better and empower you to make more informed choices about nutrition.

Everything you consume is a combination of protein, carbohydrate, fat, water and sometimes alcohol.

Macro-Nutrients

Macro-nutrients are the "big three" of the nutrition world:

Protein
Carbohydrate
Fat

They're called macro-nutrients because they're the substances you eat the most of. They provide virtually all of your energy, and most of the calories you eat come from them.

Protein

Protein is the most important macronutrient. In fact, the word protein comes from the Greek word proteios meaning "the first" or "primary." Your organs, muscles, skin, and hair are all made primarily of protein. So are many hormones, including growth hormone and insulin.

Protein cannot be stored by the body except in tiny amounts in the blood stream. So protein has to be used to build things (like muscles). Excess protein is converted to glucose for fuel.

Protein is made up of smaller components called amino acids. There are 20 different amino acids. The body can manufacture 11 of those amino acids on its own without food intake. The other 9 have to be obtained from the diet so they are called essential amino acids. A protein is considered "complete" if it has all 9 of the essential amino acids in roughly equal amounts.

If you don't get enough protein in your diet, your body would have to get some protein by breaking down muscle and organ tissue. A chronic lack of essential protein such as seen in long-term total starvation leads to loss of body function and even death (note that voluntary long-term fasting in individuals with excess fat and protein stores is a different scenario).

Food Sources of Protein

Most people get enough protein for their basic needs without really trying, since meat is a common part of most people's diets.

Most foods contain at least a small amount of protein, but the foods that contain the most protein are meat and dairy products. Beef, poultry, fish, milk, eggs, and cheese are all great sources of complete protein. Soy, beans, and nuts are also good sources of protein. Notice that a high-protein diet can be completely vegetarian by using the dairy options. Vegans can obtain necessary proteins by eating enough plants but will have difficultly getting a diet we call high protein.

Protein has a fairly small caloric value compared to other macronutrients. Each gram of protein only contains about 4 calories. Protein is the most filling of all the macronutrients. This makes it really useful for dieting. Our rapid weight loss programs tend to focus on obtaining adequate protein.

Carbohydrates

All sugars and starches are carbohydrates, or carbs for short. Carbs have only one use in the human body: fuel. In fact, carbohydrates are the body's universal fuel, usable by basically every tissue in the body. It can be stored in modest amounts as glycogen (water glucose) in your liver and muscles. Glycogen is used for immediate energy needs like steady glucose for the brain and muscular contraction.

Having said that, your body doesn't really need a specific amount of carbohydrates. If there aren't any carbs around, all of the body's tissues can get their fuel from other sources. Because of this, there isn't really a nutritional requirement for carbohydrates. In moderation, they are useful and good for lots of reasons, but your body can do without them for fairly long periods of time without much trouble. (The only exception to this is for those who do really intense exercise, such as bodybuilding or sprinting.)

Food Sources of Carbohydrates

When we talk about what kinds of food contain carbohydrates, it's helpful to divide them into two categories: starchy sources and fibrous sources.

The main type of fibrous carb source is vegetables. They contain a lot of fiber and only a little carbs. These foods are very low in calories and can safely be considered fiber-foods rather than carb-foods. Almost all vegetables fit in this category, with a few exceptions.

The main type of starchy carb source is . . . well, everything else. We're mostly talking grains and grain products like bread, pasta, and rice. A few vegetables also belong here, like potatoes, corn, carrots, and peas (notice they're some of the more popular--and yummier--veggies).

Of course, many treats and candies contain loads of sugar, and that makes them a major source of carbohydrates in most people's lives.

Carbohydrates provide about the same number of calories as protein. Each gram of pure carbs contains about 4 calories.

Since your body can go without carbohydrates for fairly long periods of time, carbs are the most obvious choice to cut when you go on a diet. This is especially true for certain people with sensitivity to carbohydrates. A more moderate technique involves swapping certain starchy and sugary carb sources for other more healthy (fibrous) sources.

Fat

Fat is perhaps the most versatile of the three macro-nutrients. Like carbohydrates, fat can be used for immediate energy needs. Together with protein, it can be used to build things in the body, like cell membranes. It can also be stored for long-term energy. That's basically what body fat is--stored energy.

Fat was once the whipping-boy of the nutrition world, but one thing modern science has taught us is that not all fats are the same. Some have more negative effects, while some are positively vital to your health.

Trans-fatty acids. These are the bad guys. Their effect on human health is completely negative. Trans-fatty acids are a man-made invention and are found in most processed foods. A good example is margarine.
Saturated fats. Some are good and some are bad, depending on who you ask. They're found mostly in animal products. Good saturated fat examples are butter and the rim of fat around a steak. However, you don't need these in your diet, since your body has plenty of stored saturated fats all on its own.
Monounsaturated fats.These are generally neutral from a health perspective, and can be considered healthy. They are found in virtually all foods that have any fat at all so you typically already get a good amount in your diet. A good example is olive oil.
Polyunsaturated fats.There are two main types--omega-3 and omega-6. Omega-3 fat is amazingly beneficial to human health, while omega-6 fat can be bad for you in high quantities--especially if you're not getting enough omega-3. A good source of omega-3 fat is fish or krill oil.

If you're like most people, you have a hard time keeping all those fats straight. Here's one way to remember: The un-fats are the unquestioned good fats (mono-un-saturated and poly-un-saturated). The others have questions or are bad.

Food Sources of Fat

Possibly the most important type of fat is a group of fats called omega-3 fatty acids. The omega-3 fats have an enormous number of positive effects on your health. There is a huge body of research showing what omega-3 fats do for you. The best and most convenient source of omega-3 fats in our food is fish.

As for the other fats, they aren't particularly healthy, and they aren't required by the body. Each gram of fat contains 9 calories--more than double that of protein and carbs. That makes fat very efficient at storing energy, but it's also very easy to get too much if you're not being careful.

For dieting purposes, the only type of fat you really need is omega-3. Even if you are eating certain types of fish it is helpful to take an omega-3 supplement.

Other Nutrients

If you understand the role of the "big three" macro-nutrients, you'll do OK. But there are a few other nutrients that you might be wondering about.

Vitamins and Minerals

What about vitamins and minerals? We all know that they're good for us. The number of functions they perform in the human body is literally unnumbered. Scientists are discovering new uses for vitamins and minerals every day. Vitamins and minerals are generally called micro-nutrients, in contrast to the "big three" macro-nutrients. Vitamins and minerals are called "micro" because you only need a very small amount of them. This doesn't mean they're unimportant by any means. You just need less of them.

There are four minerals that are particularly important to people on a low-calorie diet. They are:

Calcium (the major building block of bones)
Magnesium
Potassium
Sodium

Since you need quite a bit more of these minerals than most others, they are sometimes even added to the list of macro-nutrients. Other people call them the macro-minerals. Either way, they're very important to your health, especially on a low-calorie diet.

During rapid weight loss plans it is helpful to take a multivitamin or specialized mineral supplement to make sure you get enough vitamins and minerals, especially the first three "macro-minerals" listed above.

On an everyday diet with a lot of variety you are likely to be getting plenty of vitamins and minerals. You may decide to supplement with a generic multivitamin if you wish.

Fiber

While your body doesn't technically require it, fiber is very healthy and does a lot of great things for you. There are two main types of fiber: soluble and insoluble. You'll find both types of fiber in various vegetables and fruits. The soluble fibers will mix with water, so they take up a lot of space in the stomach and slows digestion both of which help you feel fuller longer. This makes fiber almost as filling as protein. The insoluble fibers don't mix with water, but they do help clean out your bowels which is essential for good digestive health.

Fiber provides a very small amount of calories, about 1.5 to 2 calories per gram. That's less than half the amount of calories found in protein and carbohydrates. Because fiber is so low in calories and because fiber content in most food isn't typically very large, you can essentially ignore the calorie effect of fiber itself.

Considering the low calorie amount and filling power of fiber, it makes an awesome tool for dieters who want to reduce calorie intake without feeling too hungry. (See Power of Fiber) Eating a wide variety of fibrous vegetables and fruits is encouraged and will help you feel full and get plenty of nutrients.

Alcohol

Because alcohol provides calories to the body, it is classified as a type of nutrient, but the body treats it more like a toxin. When you think of alcohol, most people think of alcoholic drinks. But anything can have alcohol in it. Right now, we're talking about alcohol in general, not just drinks.

You probably won't be surprised to hear that your body doesn't need alcohol to function. Every gram of alcohol contains 7 calories, the highest except for fat. It also alters your metabolism in a way that can promote fat gain and overall tends to sabotage weight control efforts.

Water

No list would be complete without mentioning water. Water is obviously crucial for our bodies, and is necessary for food metabolism and overall health. It contains zero calories. It's the main component that allows you to reduce the caloric impact of food you eat (the Calorie Density strategy).

Calories Summary

Fat: 9 calories per gram
Alcohol: 7 calories per gram
Protein: 4 calories per gram
Carbohydrate: 4 calories per gram
Fiber: 2 calories per gram
Water: 0 calories per gram