Nutrition for Life

Chapter 9 Nutrition for Life Learning Outcomes: Describe tips for eating right based on the Dietary Guidelines for America Describe the functions and sources of protein Describe the functions, types, and sources of carbohydrates Describe the functions of fats and health implications of excess fat intake Describe the functions of vitamins and how to obtain them Describe the functions of minerals and how to obtain them Describe the nutritional roles of water and electrolytes and the risks of excess sodium intake

Eat to Live – Don’t Live to Eat

Nutrients Essential – body cannot produce, required for proper function and structure of the body and ultimately survival Six classifications of nutrients proteins, carbohydrates, fats - energy supplying vitamins, minerals, and water

Proteins (4 cal/gr) 10-15% of diet Basic building blocks of body tissues muscle, bone, hair, blood, fingernails, antibodies, enzymes, hormones Composed of 22 amino acids 9 essential amino acids: must be obtained from food or dietary supplements Sources Complete proteins: animal sources (meat & dairy) Incomplete proteins (lacking 1+ essential amino acid) Need variety Excess protein stored as fat

Carbohydrates (4 cal/gr) 55-70% of diet Provide body with its major and first energy source Types: Simple carbohydrates (sugars) (1/4 of total carbs) “Empty calories” – lacks nutrient density #1 source of excess sugar – Pop/Soda Complex (starches) nutrient dense, steady flow of energy, found in vegetables, cereals and grains Dietary fiber – helps with digestion, lowers risk of colorectal cancer, cardiovascular disease, diabetes Recommended 20-35 grams a day Sources: whole grains, fruits, vegetables, legumes

Fats (9 calories per gram) 20-35% of diet Essential roles in the body: nourish skin, aid in absorption of certain vitamins, help in formation of cell membranes and hormones, provide stamina, insulate the body Most concentrated source of energy - Most Americans consume excessive amount contributes to obesity, heart disease, certain types of cancer

Types of Fat Saturated Fats – animal and tropical oils Greater risk of raising blood cholesterol levels (LDL) Increases risk of cardiovascular disease/cancer Should comprise 10% or less of diet Unsaturated Fats – plant sources Polyunsaturated – soybean, corn, safflower, sunflower Lowers total cholesterol and LDL, but may also lower HDL Monounsaturated – olive, canola, avocado, peanut Lowers total cholesterol and LDL Trans-fats - produced by hydrogenating vegetable oils raises blood cholesterol as much as saturated fats

Cholesterol A natural fat-like substance in the body cells of humans and animals that is used to produce hormones and cell membranes. Body produces all we need – body converts dietary cholesterol into blood cholesterol, excess can result in formation of fatty deposits in artery walls LDL “bad cholesterol” is what allows build-up HDL “good cholesterol” clears away deposits, sending them to the liver will they are processed and excreted from the body Limit dietary cholesterol, trans fat, saturated fat – choose a healthier alternative

Cholesterol

Vitamins Organic substances needed in minute amounts to serve vital roles in metabolism, growth, and maintenance of bodily processes Fat-soluble vitamins: A,D,E,K Carried by fats we eat, stored in liver and fatty tissues until needed – excess can lead to toxicity Water-soluble vitamins: B Complex, C Travel freely in bloodstream, not stored, excess is excreted in urine and sweat You can get all the vitamins you need from a balanced diet – food is better than supplements

Health Benefits of Vitamins Prevents vitamin deficiency syndromes (rare in U.S.) Reduce health risks Vitamin D – osteoporosis Vitamin B6 – relieves symptoms of PMS, asthma, enhances immune system Folic Acid – prevention of neural tube defects Antioxidants prevent or inhibit oxidation reducing the build-up of free radicals – linked to cancer and age-related disease such as cataracts, heart disease, stroke Vitamin C, Vitamin E, and Beta-carotene Phytochemicals and flavonoids

Consume from foods – absorbed by the body easier Minerals Inorganic compounds obtained from food that assist in the formation of bones and teeth, transmission of nerve signals, and the manufacture of hemoglobin Consume from foods – absorbed by the body easier Key Minerals: Health risks with too little or too much Calcium – bone health, prevention of osteoporosis Build-up bone density now Iron – forms part of the make-up of hemoglobin Deficiencies can lead to anemia, weakness, reduced physical performance, immunological functioning - women at higher risk

Water and Electrolytes Water – most important nutrient transports nutrients, removing wastes through the blood, regulating body temperature water depletion can lead to heat exhaustion, heatstroke Electrolyte: conducts electricity sodium, potassium, chloride – principle ones Sodium: attracts water into blood vessels, helps maintain normal blood volume and blood pressure excess intake increases blood pressure less than 1 tsp. of salt (added or in processed food) a day recommended