NUTR 202 1nd Edition Lecture 5 Food Labeling provide information about nutrient compositions help make healthy food choices how particular food item fits into overall meal plan Components of Nutrition Facts Panel Title Serving size is a standardized reference amount Servings per container Calories per serving Calories from fat Amount of nutrients per serving i e total fat cholesterol sodium total carbohydrates fiber protein Percentage of Daily Values DV Daily Values are based on a 2000 calorie diet Serving size influence number of calories and all the nutrient amounts listed Calorie amount is a measure of how much energy you get from a serving size Want to limit saturated fat trans fat cholesterol and sodium Want to get enough of dietary fiber Vitamin A vitamin C calcium and iron Note that daily values are recommendations for a 2 000 calorie diet Ingredient List Lists contents in order from most abundant to least abundant based on weight Required for foods with more than one ingredient These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Helpful for people with allergies or who are avoiding certain ingredients for example animal products Content claims Standard statements established by the Food and Drug Administration FDA that highlight a nutrient or characteristic of a food that might be of interest to consumers such as fat free or low sodium IMPORTANT HEALTHY low in the bad stuff but 10 A C Fe Ca Protein or Fiber FRESH raw never frozen or heated no preservatives HIGH SOURCE 20 or more of Daily Value a k a High Rich Excellent Source GOOD SOURCE 10 19 Daily Value MORE at least 10 of D V a k a Fortified Enriched Added Start of Ch 3 Digestion Before eating brain sends messages you are hungry releasing saliva Shows main goals of digestion processes 3 macronutrients to provide energy and other fxns We ingest food so its digested into small particles absorbed and the food we don t absorb will be eliminated What is process of how food is in your body THROUGH ABSORBTION Ex fiber passes through GI tract not absorbed When we eat food is DIGESTED then useful nutrients are ABSORBED and finally the waste products are ELIMINATED Digestion occurs in the Gastrointestinal Tract GI GI Tract Path Long tube Mouth pharynx esophagus sphincter stomach sphincter small intestine sphincter large intestine rectum anus Digestion is Mechanical and Chemical Mechanical Digestion Breakdown of food into smaller pieces through chewing and or moving it through the GI tract through peristalsis Chemical Digestion Breakdown of the large molecules of food into smaller absorbable molecules It involves digestive juices and enzymes Mucus is secreted from mucosal cells lining the digestive tract Moistens lubricates and protects Enzymes speed up reactions In the dig tract they help breakdown larger molecules into smaller ones Hormones chemicals secreted from cells which travel through the bloodstream to signal cells in another part of the body Digestion Allows us to Absorb Nutrients from Foods small intestine In general Amylase digest carbs Lipase digest fats Protease digest proteins pepsin in stomach Mechanical Peristalsis Muscular contractions in a wavelike manner that moves food through the GI tract and mix it with the enzymes juices Gastrointestinal tract The GI tract is a series of hollow organs joined in a tube from the mouth to the anus Food passes through the digestive tract Accessory organs include the salivary glands liver gall bladder and pancreas Food does not pass through these organs Lumen is the inside part of the digestive tract which still is considered technically outside the body Ingestion Food enters the GI tract not inside the body via the mouth Mechanical and chemical digestion begins Saliva is secreted from salivary glands after the sight smell or presence of food Contains lubricants enzymes and other substances Teeth Chewing Break down food particles Tongue helps mix food and aids chewing Bolus formed Pharynx Responsible of swallowing Part of the digestive system and respiratory system Epiglottis small flap which blocks food from entering wind pipe during swallowing Esophagus Muscular tube that propels food into the stomach through peristalsis Lower esophageal sphincter muscular ring at end of esophagus normally tightly closed relaxes to allow food to pass into the stomach 3 muscle layers long circular and diagonal Circular folds keep it moving chyme is a combination of food and different gastric juices Stomach Temporary storage of food Stomach lining produces gastric juice containing Water Hydrochloric acid pH of HCL is 1 0 1 Kill microrganims 2 unfolds proteins 3 activates pepsin 4 inhibits amylase Pepsinogen 1 Activated into digestive enzyme pepsin Mucus 1 Protects stomach lining from pepsin and hydrochloric acid Churning of stomach muscles to mix food Little absorption Water alcohol aspirin End result CHYME Leaves the stomach to enter the small intestine through a sphincter Pyloric sphincter Stomach emptying is regulated by signals from the small intestines and is affected by meal size and composition SI has circular folds that increase SA villi that have projections vascularized and has microvilli on the villi for additional surface for nutrients to be absorbed 20 ft long Segmentation mixes chyme with digestive juices Peristalsis waves moves food along tract Chemical Digestion Dig enzymes from pancreas and brush border digest most classes of nutrients Absorption Nutrients are absorbed into blood and lymph through enterocytes Diffusion Movement of substances from areas of higher concentration to areas of lower concentration Facilitated diffusion Diffusion through a membrane protein Simple diffusion diffusion across a membrane Osmosis diffusion of water across membrane Active transport Movement of substances across membranes against concentration gradients requires energy membrane protein 1 Simple diffusion example is vitamins and fatty acids lipophilic 2 Osmosis example is water 3 Facilitated diffusion example is fructose 4 Active transport example is glucose amino acids ion Transport Pathways Bloodstream Water soluble nutrients and smaller products of fat digestion are absorbed into capillaries Liver Lymphatic system Larger fats and fat soluble vitamins are absorbed into lacteals The Liver regulates blood nutrients Once the nutrients are absorbed from the small intestine most enter the PORTAL