1. Chapter 18.1a
Nutrition

2. Why do you eat?
You need food to carry out your daily activities. The nutritional value of food is very important. You want food that provide a good amount of nutrients.
Nutrients are substances in food that provides energy and materials for cell development, growth, and repair.

3. Energy Needs You body needs energy for every activity it performs.
How much energy you needs depends on body mass, age, and activity level.
This energy comes from foods you eat.
We measure the amount of energy in food using a Calorie. A Calorie is the amount of heat necessary to raise the temperature of 1 kg of water 1 ˚C.
A raw carrot may have 30 Cal – that means your body has 30 Cal of energy available to use.

4. Classes of Nutrients
6 kinds of nutrients are available from food – proteins, carbohydrates, fats, vitamins, minerals, and water.
Organic nutrients are proteins, carbohydrates, vitamins, and fats.
Inorganic nutrients are water and minerals (they do not contain carbon).
Carbohydrates, fats, and proteins must be broken down for our bodies to use them, water, vitamins, and minerals do not require digestion.

5. Proteins
Proteins are used for replacement and repair of body cells and for growth. They are large molecules that contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
Proteins are made of amino acids. Different foods contain different amounts of proteins.
You body needs amino acids to make thousands of proteins in your cells. There are 8 essential amino acids that your body cannot make and you must get from food.
Eggs, milk, cheese, and meat contain complete proteins (all essential amino acids).
Incomplete proteins are missing one or more essential amino acids.

6. Carbohydrates
Carbohydrates are the main source of energy for your body. Each carb is made of carbon, hydrogen, and oxygen atoms. Energy holds the atoms together and when they are broke apart that energy is released and can be used.

7. There are 3 types of carbohydrates: sugar, starch, and fiber.
Sugars are simple carbohydrates – this table sugar, fruits, honey, and milk
Starch and fiber are complex carbohydrates.
Starch is found in potatoes and food made from grains like pasta.
Fiber is found in the cell walls of plants – whole grain breads and cereals, beans, peas, and other veggies and fruits are good sources of fiber.

8. You should choose snacks that have nutrients in them
You should choose snacks that have nutrients in them. Foods high in sugar and fat can have a lot of Calories that supply energy, but they do not give you all of the nutrients your body needs.

9. Fats
Fats, or lipids, are very important because they supply energy and help your body absorb vitamins.
Fat tissue cushions internal organs. Cell membranes are made of fat.
A gram of fat can release 2x the amount of energy as a gram of carbohydrate.
Excess energy you get from food you eat is converted and stored as fat to use for later.

10. Fats are classified as unsaturated and saturated based on chemical structure.
Unsaturated fats are liquid at room temperature. Vegetable oils and fats found from seeds are unsaturated.
Saturated fats are found in meats, animal products, and some plants and are usually solid at room temp.
Saturated fats can cause high cholesterol. This can cause deposits to form on the inside walls of your blood vessels and that blocks the blood supply and increases blood pressure. This can cause heart attack and stroke.