NUTRIT

ION

CHAPTER 1

5 LESSON 1

• Why do you eat?

• Why does your body need each of the six groups of nutrients?

• Why is eating a balanced diet important?

A Calorie (Cal) is the amount of energy it takes to raise the temperature of 1 kg of water by 1°C.

All foods give your body energy to use.

The amount of energy in food is measured in Calories.

Why do you eat?

The amount of energy a person needs depends on factors including weight, age, activity level, and gender.

Why do you eat? (cont.)

• Food is made of nutrients—substances that provide energy and materials for cell development, growth, and repair.

The six groups of nutrients are proteins, carbohydrates, fats, vitamins, minerals, and water.

Each nutrient has a different function in the body, and they are all needed for homeostasis.

A protein is a large molecule that is made of amino acids and contains carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.

Groups of Nutrients

Combinations of 20 different amino acids make up the proteins in the body.

Groups of Nutrients (cont.)

Proteins relay signals between cells, protect against disease, provide support to cells, and speed up chemical reactions.

Groups of Nutrients (cont.)

Carbohydrates are molecules made of carbon, hydrogen, and oxygen atoms and are usually the body’s major source of energy.

Carbohydrates are commonly starches, sugars, or fibers.

Fats, or lipids, provide energy and help your body absorb vitamins.

Groups of Nutrients (cont.)

Fats are a major part of the cell membrane and help insulate the body against cold temperatures.

Fats are often classified as either saturated or unsaturated.

A diet high in saturated fats can increase levels of cholesterol, which can increase the risk of heart disease.

Groups of Nutrients (cont.)

Vitamins are nutrients that are needed in small amounts for growth, regulating body functions, and preventing some disease.

Minerals are inorganic nutrients—nutrients that do not contain carbon—which help the body regulate many chemical reactions.

Groups of Nutrients (cont.)

Your body needs water for chemical reactions to occur.

Your body takes in water when you eat or drink and loses water when you sweat, urinate, and breathe.

When lost water is not replaced, you can become dehydrated.

Groups of Nutrients (cont.)

Nutritious foods come from the major food groups, which include grains, vegetables, fruits, oils, milk products, and meats and beans.

A healthful diet includes carbohydrates, proteins, fats, vitamins, minerals, and water.

Healthy Eating

Food labels help you determine the amount of protein, carbohydrates, fats, and other substances in food.

Healthy Eating (cont.)