Читать книгу Nutrition For Dummies - Carol Ann Rinzler - Страница 12

Technically speaking, nutrition is the science of how the body uses food. In the broader sense, it is nourishment — the process of providing food and the study of what that food offers. In fact, nutrition is life. All living things, including you, need food and water to live. Beyond that, you need good food, meaning food with the proper nutrients, to live well. If you don’t eat and drink, you’ll die. Period. If you don’t eat and drink nutritious food and beverages your body may pay the price:

 Your bones may bend or break (not enough calcium).

 Your gums may bleed (not enough vitamin C).

 Your blood may not carry oxygen to every cell (not enough iron).

And on, and on, and on. Understanding how good nutrition protects you requires a familiarity with the language and concepts of nutrition.

Knowing some basic chemistry is helpful. (Don’t panic: Chemistry can be a cinch when you read about it in plain English.) A smattering of sociology and psychology is also useful, because although nutrition is mostly about how food revs up and sustains your body, it’s also — as I explain in Chapter 15 — about the cultural traditions and individual differences that explain why you like the food you like.

You’ve heard “You are what you eat” before. As a matter of fact, it’s the first sentence at the top of this chapter. But it bears repeating, because the human body is built with the nutrients it gets from food: water, protein, fat, carbohydrates, vitamins, and minerals.

Nutrition’s primary task is to figure out which foods and beverages (in what quantities) are required to construct and maintain every one of your organs and systems. To do this, nutrition concentrates on food’s two basic attributes: energy and nutrients.

 Energy is the ability to do work. The amount of energy in food is measured in calories, the amount of heat produced when food is burned (metabolized) in your body cells. You can read all about calories in Chapter 5, but for starters, all you need to know is that food is the fuel on which your body runs. Without enough food, you don’t have enough energy. No surprise there.

 Nutrients are the natural chemical substances your body uses to build, maintain, and repair tissues. They also make it possible for cells to send messages back and forth to conduct essential chemical reactions such as the ones that make it possible for you toBreatheMoveEliminate wasteThinkSeeHearSmellTasteand do everything else common to a healthy living body.