Six Classes of Nutrients


Six Classes of Nutrients

Nutrition Unit

Lesson 2

What Is Nutrition?

 The study of what people eat and of eating habits and how these affect health status

 Nutrient = substance in food that helps with the body processes, growth and repair of cells, and provides energy.

Calorie : unit of energy produced by food; used by the body

Six Classes of Nutrients








 Needed for:


To build, repair, and maintain body tissues

Regulate body processes

Supply energy

 Help body maintain strength; resist infection

 1 gram of protein = 4 calories

 Protein deficiency may stunt growth or affect tissue and mental development

 Excess protein is stored as fat or burned as energy


Two kinds:

Complete protein – contains all essential amino acids

 Amino acids = building blocks of protein

 Examples: meat, fish, poultry, milk, yogurt, eggs

Incomplete protein – from plant sources that does not contain all of the essential amino acids

 Examples: grains, legumes, nuts and seeds


 Main source of energy for the body

 Includes sugars, starches, and fiber

 Supply 4 grams of energy per gram of food

 Excess carbs are stored as fat

 Includes:

Vegetables, beans, potatoes, pasta, breads, rice, bran, popcorn, and fruit


 Two types:

Simple carbohydrates – sugars that enter the bloodstream rapidly; provide quick energy

 Examples: fruits, honey, milk, processed sugar, cakes, candy, ketchup, spaghetti sauce, and soda pop

 Provide calories, but few vitamins and minerals

Complex carbohydrates – starches and fiber

Most of the calories in diet are complex carbs

Examples: grains (breads/pasta), vegetables

 Starch: food substance made and stored in plants – provide long-lasting energy


 Fiber

Part of grains and plant foods that cannot be digested – also called roughage

Helps move food through digestive system

Helps prevent constipation and other intestinal problems

Foods with fiber make you feel full

Reduces blood cholesterol level and risk of developing heart disease

Includes wheat, bran, cereals, fruit, and vegetables


 Provides energy; helps body store and use vitamins

 One gram of fat = nine calories of energy

 Store and transport fat-soluble vitamins

Fat-soluble vitamin – dissolves in fat; can be stored in the body (ex.: vitamins A, D, E, and K)

 Surround and cushion internal organs

 Give taste and texture to food

 Need fat to maintain body heat, store and use vitamins, maintain energy reserve, build brain cells/nerve tissues


Two Types

Saturated fat – comes from dairy products, solid vegetable fat, and meat and poultry

Usually solid in form

Contribute to person’s cholesterol in blood

 Cholesterol = fat-like substance made by the body and found in certain foods

 Can be lowered by eating fewer saturated fats

(healthy levels lower the risk of heart disease and some cancers)

Unsaturated fat – obtained from plant products and fish

 Usually liquid

 Polyunsaturated fat – sunflower, corn, and soybean oils

 Monounsaturated fat – olive and canola oils


 Helps body use carbs, proteins, and fats

 Two types:

Fat-soluble (A, D, E, and K)

Water-soluble – dissolves in water; cannot be stored by the body in significant amounts

 Examples: B complex, C


 Regulates chemical reactions in the body

 Two types:

Macro : required in amounts greater than 100 milligrams

 Examples – calcium, sodium

Trace : needed in very small amounts; just as important as macro minerals

 Examples – iron, zinc


Involved with all body processes, makes up basic part of blood, regulates body temperature, helps waste removal, cushions spinal cord and joints

Makes up approx. 70% of body mass

Can survive only a few days without water

Dehydration : water content of body has dropped to an extremely low level

 Caused by a lack of water intake, dry environment, fever, vomiting, diarrhea, hot weather, exercise

Important to drink 6-8 12 oz. or more glasses of water a day

Don’t substitute pop and caffeinated drinks – act as diuretics (product that increases the amount of urine excreted)

Signs of Dehydration

 Dizziness

 Fatigue

 Weakness

 Dry mouth

 Flushed skin

 Headache

 Blurred vision

 Difficulty swallowing

 Dry, hot skin

 Rapid pulse

 Frequent need to urinate