Chapter 30.2-Food and Nutrition

Food Energy Measured in calories calorie Dietary Calories Amount of heat needed to raise the temperature of 1 gram of water 1 degree Celsius Dietary Calories Also called kilocalories Equal to 1000 calories Written with capital C

What is Food Used For? Energy Build and repair body tissues There are at least 45 different components in food that the body needs that it can’t make itself These components are called nutrients

Nutrients Water Found in all cells Necessary for chemical reactions Helps maintain body temperature 1 liter of water a day is necessary to replace what is lost Lost through urination, sweating, breathing

Nutrients Carbohydrates Provide about 4 Cal/gram Simple carbs provide quick energy Complex carbs take longer to break down, and provide energy over a longer period of time Complex carbs provide fiber, or cellulose, which helps move waste through the digestive system Complex carbs with lots of fiber are healthiest to eat

Carbs and Stored Energy Carbs that are not immediately used can be stored as a complex carb Converted into glycogen Stored in the liver, muscles, and brain Carbs that are not used can also be turned into body fat

Nutrients Fats Unsaturated fats are the healthiest to eat Provide about 9 Cal/gram Help the body absorb fat-soluble vitamins Are a part of cell membranes Provide insulation and protect organs Can act as hormones Store energy long-term Unsaturated fats are the healthiest to eat

Nutrients Proteins Provide 8 essential amino acids Provide about 4 Cal/gram Are the raw materials for many body parts, especially muscles Also control chemical reactions (enzymes!) Can act as hormones Provide 8 essential amino acids Lean meat is the healthiest to eat (93% fat or less)

Nutrients Vitamins Fat-soluble vitamins Water-soluble vitamins Organic molecules that the body needs in very small amounts Needed for chemical reactions Fat-soluble vitamins A, D, E, K Can be stored in fat tissue Water-soluble vitamins B complex, C Cannot be stored, and are lost through urination

Nutrients Minerals Inorganic molecules that the body needs in very small amounts Many of them are elements Water-soluble, and are lost through sweat, urination, and solid waste

What Should You Eat? A balanced diet is based on Percent Daily Values For a 2000-Calorie diet Calories can change with age, activity level, and age 2200 Cal for female teens, 2800 Cal for male teens A balanced, healthy diet contains: Lean proteins for 8 essential amino acids Complex carbs for energy and fiber Unsaturated fats in small amounts