digestion pt2 pg 5-6

Energy and Nutrition require

development grown and repair

nutrients are

chemicals form the environment that we need to live

Macronutrients

• Carbohydrates, lipids, proteins

Micronutrients

Vitamins, minerals

Essential nutrients

Amino acids, water, some minerals, oxygen

Energy Requirements Needs vary by individual

Degree of muscular activity
Body temperature
Rate of tissue and body growth
Basal Metabolic Rate (BMR) – greatest energy requirement

BMR

measures the rate at which the body expends energy under basal conditions

ex of bmr

When awake, at rest
After an overnight fast
In a comfortable, controlled environment

BMR indicates

the amount of energy used to support activities of the brain, heart, lungs, liver, and kidneys

Energy Balance

Occurs when caloric intake equals expenditure from the BMR and muscular activity

Positive energy balance

Caloric intake exceeds expenditure

Tissues store excess nutrients

Increase in body weight

Negative energy balance

Caloric expenditure exceeds intake
Stored minerals are mobilized from tissues Weight loss

Appetite Control

Eating is

a homeostatic mechanism

Desire for food is driven by things such as

smell, taste, texture, and neural signals

Appetite is

the drive the compels us to seek food

Insulin regulates

fat stores by stimulating adipocytes to convert glucose to glycogen

Eating stimulates

adipocytes to secrete the hormone leptin

Leptin suppresses appetite

and stimulates metabolic rate

Ghrelin and neuropeptide Y

enhance appetite

Complex carbohydrates include polysaccharides

Starch from plant foods Glycogen from meats Cellulose

Simple carbohydrates

Disaccharides, Monosaccharides

Disaccharides

Milk, cane sugar, beet sugar, and molasses

Monosaccharides

Honey and fruits

Most glucose is oxidized in glycolysis

and Forms ATP

Glucose

required for neurons to function

Excess glucose

Forms glycogen Stored in liver and muscles