digestive system
DESCRIPTION
Digestive System. Macromolecules. Carbohydrates Preferential metabolism Complex Starch from grains and vegetables Simple Mono (fruits) & Disaccharides (sugar, dairy) Cellulose (structural polysaccharide) roughage. ATP!. Atkins. - PowerPoint PPT PresentationTRANSCRIPT
Digestive System
Macromolecules
• Carbohydrates– Preferential metabolism• Complex
Starch from grains and vegetables• Simple
Mono (fruits) & Disaccharides (sugar, dairy)• Cellulose (structural polysaccharide)
roughage
ATP!
Atkins• Not enough Carbs
(note: brain cannot metabolize fatty acids –albumin! BBB)
• Body starts burning fatty acids• Produces ketones (acidic)• Lowers pH • Low insulin= ketoacidosis/ diabetic coma
(medical emergency)– Nauseau, vomiting, dehydration, LOC
Lipids• Energy Source/ Cell membranes– Fats• Triglycerides (most common)• Stored (adipose)
• Phospholipids• Cholesterol• Metabolized:
Triglycerides –(duodenum)Fatty acids + Glycerol
Saturated UnsaturatedAnimalsFatty Plants
SeedsNutsOils (plants)
Fats/ Lipids• Free Fatty acids
•Glycerols
•Combine to form Triglycerides
Cholesterol
• Only from animal sources• Needed in cell functions– Body produces approx. 100 mg/day– Consumption should be < 200 mg/day
• Good vs. Bad Cholesterol– HDL pick up fatty acids from around body– LDL and VLDL stick to arteries around body
Fats needed for…
• Energy Storage• Absorption of vitamins (A, D, E, K)
• Stored directly after consumption
*
Digestion of Fats into intestines
Protein
• needed for– Enzymes!– muscle– immune system
– As last resort….ketosis for higher priority muscles
Sources
• Meat• Fish • Dairy
Amino Acids•20 amino acids total
• 9 essential amino acids
• 11 non essential amino acids
When broken down…
• Ketosis (only when no carbs)– energy production when no energy from glucose
for brain, heart, etc.• protein synthesis for muscles & liver• Energy for muscles, kidney, & adipose
• ↑ insulin, testosterone → ↑ protein synthesis
Calorie:
• Unit of Energy• By Definition:– Amount of heat required to raise temperature of
1 gram of water by 1 degree celsius
LOOKING AT CALORIES:
• Proteins= 4 calories/ gram• Carbohydrates= 4 calories/ gram
• fat= 9 calories/ gram– So much more efficient storage!
Finding %:
• Can take grams and divide by total grams to find % in food item
• Ideal % for intake:– 30% carbohydrates– 40% proteins– 30% fat
Diet• one-third of children and more than two-thirds of
adults in the United States are overweight or obese
• What is a "Healthy Diet"?The Dietary Guidelines describe a healthy diet as one that
– Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products
– Includes lean meats, poultry, fish, beans, eggs, and nuts; and
– Is low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars.
Dietary guidelines:
• Enjoy your food, but eat less. • Avoid oversized portions. • Make half your plate fruits and vegetables. • Switch to fat-free or low-fat (1%) milk. • Compare sodium in foods like soup, bread, and
frozen meals – and choose the foods with lower numbers.
• Drink water instead of sugary drinks.
BMR
• Rate body expends energy at rest• Affected by:– Sex– Temperature– Size– Hormone activity
BMI
• Measure of body fat based on a height/ weight ratio
• Inaccurately used in medical field• Limitations:– Athletes– Age– elderly
Food Pyramid
• Designed as a guide to determine how much of certain foods should be consumed
• Move away from standard 2000 cal diet but suggests government guidelines of recommended allowances
Vitamins• Organic• Classified by solubility
Vitamins
• A: production of visual pigments• D: skin, promote Ca/ P absorption (bone
growth/ remodeling)• E: antioxidants• K: (prothrombin) blood clotting• B: metabolism of proteins, lipids, & carbs• C: collagen; metabolize AA, Fe absorption
Minerals
• Ca; P: bones & teeth• Fe: blood• CaPO4- bones• Na, Cl, K- Blood