Principles of NutritionPrinciples of Nutrition

NutritionNutrition

Linked to overall good health Diet includes sufficient amounts of

nutrients to carry out normal tissue growth, repair, and maintenance of the body

NutrientsNutrients

Essential – Carbohydrates– Fats– Proteins– Minerals– Vitamins– water

Non-essential– Body makes

High Nutrient DensityHigh Nutrient Density

Nutrient density and calorie content not related (low calories; high nutrients)

Refers to foods rich in nutrients relative to the energy content

Should be as close to the original product

– Grapes vs. grape juice vs. grape drink

Essential NutrientsEssential Nutrients

Fuel nutrients

– Carbs, fats, proteins

– Source of calories for the body

– Carbs = high octane fuel

– Carbs and fats primarily source of energy for physical activity

CarbohydratesCarbohydrates

From plants Primary energy providers Simple vs. complex Transformed in the body to the form of

glucose 55%-60% of total caloric intake

– 4 calories/gram

Simple CarbohydrateSimple Carbohydrate

Contain one or two sugars in each molecule

Monosaccharides (glucose, fructose, galactose)

Disaccharides (sucrose, lactose, maltose)

Empty calories (no nutritional value)

Complex CarbohydratesComplex Carbohydrates

Polysaccharides Starches, dextrins, glycogen Rice, cereal, beans, breads, etc.

FiberFiber

Indigestible portion of fruits, veggies, grains

Form of complex carbohydrate Can be soluble or insoluble

FatsFats

Sources of fats

– Vegetable oils

– Animal oils

– Butter

– Cheese 1 gram of fat contains 9 calories

– Highest of any nutrient

Saturated FatSaturated Fat

Animal products and by-products Typically solid at room temperature Will lead to total serum cholesterol

levels No more than 10% of daily total caloric

intake Primary culprits in CAD

Unsaturated FatUnsaturated Fat

Subdivided into monounsaturated and polyunsaturated fats

Monounsaturated fats are more desirable as they tend to lower the “bad” cholesterol and not the “good” cholesterol (may protect against heart disease)

ProteinsProteins

Essential for maintenance and repair of all body tissues, enzymes, and some hormones

Not the preferred energy source

Functions of ProteinsFunctions of Proteins

Carry oxygen (hemoglobin)

Fight disease (antibodies)

Catalyzes reactions (enzymes)

Movement (actin/myosin)

Connective tissue (collagen)

Clotting of blood (prothrombin)

Messenger (hormones)

Proteins Cont.Proteins Cont.

Amino acids– 20 found in food; 9 are essential

Animal products=complete proteins Plant products=incomplete proteins 12-15% of daily caloric intake Creatine: effectively builds mm; long

term effects unknown; found in fish; easily obtained through diet

VitaminsVitamins

13 vitamins, none manufactured by the body

Regulators of body processes No caloric value Can be either fat-soluble or water-

soluble

Fat-Soluble VitaminsFat-Soluble Vitamins

Vitamins A, D, E, and K Bind to fat molecules and are absorbed

in the small intestine Excessive amounts of vitamins can be

toxic

Water-Soluble VitaminsWater-Soluble Vitamins

All B complex vitamins and C Cannot be stored in the body

MineralsMinerals

Approx 25 minerals Essential to body processes Stored in liver and bones Aid in mm contractions and physical

activity

Sodium and PotassiumSodium and Potassium

Transmission of nerve impulses Aids in heart functioning

IronIron

Helps in oxygen transport (hemoglobin) Anemia=insufficient iron consumption

– Blood volume is below normal

– Fatigue Found in red meats

CalciumCalcium

Most abundant in body

Formation of bones, teeth, blood clotting, and mm contraction

Osteoporosis Supplementation

WaterWater

Most essential nutrient Body is 70% water 8 glasses daily More needed if activity is in heat

Nutrient RecommendationNutrient Recommendation

RDA=recommended daily allowance Nutrient requirement for any vitamin or

mineral is the amount needed to prevent diseases

Food Guide PyramidFood Guide Pyramid

SupplementsSupplements

Most supplements are not necessary if eating a well balanced diet

Body processes foods better than pills 1-a-day multivitamin Medical conditions

– Anemia, osteoporosis, female athlete triad

Food for PerformanceFood for Performance

Carbohydrate loadingIf exercising > 1 hour per day,

70% of calories should come from carbohydrates

Re-supply system with carbohydrates within an hour of prolonged activity

CaffeineCaffeine

CNS stimulant Increases

– Alertness– Nervousness– Irritability– Increased heart rate– Headaches– Decreases fatigue

Nutrient Content DescriptorsNutrient Content Descriptors

Free Low Lean Extra lean High Good source

Reduced Less Light More Healthy Fewer

Pgs. 259-260