Nutrition, part 2 Because 1 part isn t enough!
4. Calories and Caloric Intake Calories per gram of our Macro and Micro nutrients Macro Carbohydrates: 4 cal/g Fats: 9 cal/g Proteins: 4 cal/g Micro Vitamins: Nil Minerals: Nil
What s the amount of calories in this? Pasta Bolognese Macronutrient Mass Total Calories Carbohydrates 75 g Protein 20 g Fat 8 g Total -
What s the amount of calories in this? Chicken Broth Macronutrient Mass Caloric Intake Carbohydrates 0.9 g Protein 1.4 g Fat 1.3 g Total -
5. The Food Groups There are four main food groups 1. Fruits and vegetables 2. Grain products 3. Milk and alternatives 4. Meat and alternatives
5 a) Fruits and vegetables Good source of fibre, potassium, vitamin A (healthy skin, fights infections) and vitamin C (protects gums and teeth) Main macro-nutrient in fruits and vegetables is carbohydrates Suggested serving size per day Teenagers (14-18): 7 (females) 8 (males) Adults (19+): 7-8 (females) 8-10 (males)
5 b) Grain products Good source of fibre, vitamin B12 (helps to make DNA), iron and magnesium (key in energy production and enzyme function) Main macro-nutrient in grains are carbohydrates and protein Suggested serving size per day Teenagers (14-18): 6 (females) 7 (males) Adults (19+): 6-7 (females) 8(males)
5 c) Milk and alternatives Good source of calcium, Vitamin D (helps keep healthy bones and teeth), zinc and magnesium Main macro-nutrient in milk and alternatives are protein and fat Suggested serving size per day Teenagers (14-18): 3-4 (females) 3-4 (males) Adults (19+): 2 (females) 2 (males)
5 d) Meat and alternatives Good source of iron, Vitamin B and zinc (growth, fighting infections) Main macro-nutrient in meat and alternatives are protein and fat Suggested serving size per day Teenagers (14-18): 2 (females) 3 (males) Adults (19+): 2 (females) 3 (males)
6. Food labels, what do they mean? Food labels help determine what foods you should eat They have the breakdown of all nutrients, along with the suggested daily value on them Foods that do not require nutrition labels Fresh fruits and vegetables Fresh meat Fresh fish
6. Food labels, what do they mean? To figure out which food is better for you to eat, you need to compare the nutrition facts **You have to make sure the serving sizes are the same - If they are not, you need to determine the conversion factor
Fibre One Cereal Compare values without milk Compare the following traits Calories Total fat Sodium Total Carbohydrates Sugar Protein
Fibre One Cereal More calories: More fat: More sodium: More carbs: More sugar: More protein:
7. The digestive system System whose role is to break down and transform food into nutrients that can be used by the body for fuel Four main functions of the digestive system 1. Ingestion and propulsion of food (take in and push food along) 2. Digestion of food (break down food into smaller parts) 3. Absorption of food (take in broken down food) 4. Elimination of waste (get rid of what body doesn t use)
7. The digestive system There are two types of digestion Mechanical: Physically breaking down food into small substances o Chewing: crushing and grinding food, by the teeth in the mouth o Churning: muscle contractions in the stomach mixing food with gastric juices Chemical: Chemicals in secretions (like saliva and gastric juices) breaking down complex molecules into simple ones which can be absorbed by the body
Organ Function Mouth Pharynx Esophagus Stomach Liver Pancreas Small Intestine Large Intestine Begin to mechanically and chemically break down food, produces saliva to break down starches (complex carbohydrates) Carry food to esophagus during swallowing Carry food to stomach during swallowing by peristalsis Continue to mechanically and chemically break down food, produces gastric juices to break down proteins Produces bile to break down fats in the small intestine Produces pancreatic juices to break down fats, proteins and carbohydrates in the small intestine Continue to chemically break down food, produces intestinal juices to break down fats, proteins and carbohydrates, absorbs nutrients Absorbs water
7. The digestive system Digestion starts in the mouth Teeth chew the food into smaller parts Saliva from the salivary gland start to break down starch Food is called bolus at this stage Chewed bolus (food) is swallowed into the esophagus. The esophagus pushes bolus down by peristalsis contractions into the stomach
7. The digestive system In the stomach Churning mixes food and secretions together, continuing the mechanical breakdown and chemical breakdown Gastric juices start to break down protein Food is called chyme at this stage Chyme then enters the small intestine after 2.5 to 3 hours in the stomach Note: Pepsin in gastric juices require a ph of 2-3 to work properly. So, your stomach makes hydrochloric acid so it can break down protein!
Figure 1: A unemployed stomach
7. The digestive system In the small intestine Intestinal juice and pancreatic juice breaks down fats, protein and carbohydrates Bile breaks down fats Broken down macronutrients (carbohydrates glucose, lipids/fats fatty acids, proteins amino acids) are absorbed by villi in the small intestine Peristalsis contractions pushes chyme through the small intestine and into the large intestine
7. The digestive system In the large intestine DIGESION IS FINISHED Water from chyme is absorbed The waste and left overs is called feces at this point The rectum stores the feces until it is expelled, where it exits the body through the anus