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Nutrition. Digestion – chemical process of breaking down food Begins with your first bite of food Saliva – contains enzymes that begin breaking down food (amylase) . Continues in the stomach and ends in the small intestine
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Digestion – chemical process of breaking down food • Begins with your first bite of food • Saliva – contains enzymes that begin breaking down food (amylase)
Continues in the stomach and ends in the small intestine • All food is broken down into small molecules that are then absorbed and used by the body • Usually glucose, fats, and proteins
Energy • Food gives us energy so we can do our daily activities • What do you do in a day?
BMR – basal metabolic rate • Even when we rest we still use energy • What is consuming energy at this time?
Daily intake of energy containing compounds • Fats – 9 Cal/gram • Carbs – 4 Cal/gram • Protein – 4 Cal/gram • How much do you need to bring in? • Energy in food = energy used + energy stored
How much energy do you need? • A typical person needs 10 Cal/lb of weight • If you are very active you need 1.6x this amount of Calories • If you have low activity you only need 1.3x this amount
Sugars • Remember glucose, glycogen, amylose and amylopectin? • What happens with cellulose, pectin, and plant gums? • The later are called dietary fiber.
Dietary fiber is either soluble or insoluble • Soluble fiber is pectin and the gums • Insoluble fiber is the cellulose
Lipids • Fats, we get them in meats, fish, vegetables and dairy products. • It is recommended that 20-35% of our diet contain fats • But too much fat and cholesterol can lead to atherosclerosis
HDLs and LDLs • Lipids bind with protein to become water soluble • LDLs carry lipids from the liver throughout the blood stream to cells these can lead to plaque build ups • HDLs are the good cholesterol because they carry excess cholesterol to the liver and convert it to bile.
Diets higher in soluble and insoluble fiber help increase the HDL content of your body. Usually we have 65% LDL and 25% HDL and 10% other cholesterol floating around
Proteins • Meat, fish, eggs, cheese, and beans are high protein foods • These are necessary to provide amino acids for our own proteins • We rarely see protein deficiencies in our diets but developing countries do fairly often
Vitamins and Minerals • Our bodies need vitamins and minerals in addition to carbohydrates, lipids, proteins, and nucleic acids • A vitamin is an organic chemical that assists in biochemical reactions • A mineral is an inorganic chemical that has a variety of roles in the body.
Fat soluble • Vitamin A – found as beta carotene but converted to the vitamin during digestion • More than 200mg in a single dose can cause vomiting, fatigue and headaches • Vitamin D - created by exposure to the sun, we don’t need any in our diets usually. • Deficiency can lead to rickets • Excess causes calcium buildup and can appear on the tympanic membrane causing deafness
Vitamin E – antioxidant and helps maintain cell membrane stability • No known overdose problems but taking excess is not advised • It is the only vitamin that breaks down when frozen • Vitamin K – blood clotting • Overdoses are very bad and can lead to clots in the blood
Water soluble • Vitamin B and C • There are 8 different B vitamins all of which work together so excess or deficiencies in one lead to problems with all • B6 is the most active, used in over 60 reactions • Excess can lead to nerve damage or paralysis (more than 60x the daily recommended dose)
Vitamin C – supports the immune system in fighting off bacteria, viruses, also works to minimize toxic substances and drugs • It is also needed for collagen which is used in connective tissues like cartilage
Food Additives • What do we add to food?
Nutrition • Our diets consist primarily of carbohydrates. • Insulin is the protein that moves glucose from the blood stream into the cell
Dietary diseases • Diabetics have difficulty releasing enough insulin or any at all depending on the severity of diabetes. • If no glucose is moved into your cells then you will not make ATP
Hypoglycemia – basically the opposite of being diabetic • The body responds to excess glucose in the body by releasing too much insulin which drops glucose levels well below normal