Chapter 10: Food For Life
10.1: Assessing Nutrients
Page 198
Science 14 and 10-4 with Mrs. M
This week
• Today 10.1 and 10.2• Tuesday 10.3 digestive system• Wednesday 10.4• Thursday Review – Food log due (One day log)• Friday Test
10.1: Assessing Nutrients
• How do diet and lifestyle affect circulatory and digestive systems?
How do diet and lifestyle affect circulatory and digestive systems?
• Food influences body functions• You need nutrition in order to live
Nutrition
• Nutrition is a branch of science that studies foods and how the body uses them
• Nutrients are substances found in foods
• The nourishment and energy help the body to maintain its cells, tissues, and organs, and to support growth and development
Malnutrition
• Malnutrition occurs when essential nutrients are missing from a diet.
• It can occur when people eat too little. • It can also occur if people eat enough volume
but make poor food choices and are therefore missing important nutrients
Malnutrition
• Malnourished people often suffer from high levels of sickness and disability
• They also have shorter life spans• Those who lack an adequate supply of food
may die from starvation• Children who lack proper nutrients may not
grow properly and may suffer from brain damage
What nutrients do we need?
• Carbohydrates• Proteins• Fats• Vitamins• Minerals• Water
What nutrients do we need?• Carbohydrates: in the form of sugars and
starches are the primary source of energy for your body
What nutrients do we need?
• Proteins: build body tissue, regulate chemical activity, and supply energy
Nutrients• Fats: are stored in the body for use as an
energy source when carbohydrates are in short supply
Nutrients• Vitamins: are organized according to whether they
can be absorbed in fat or water
• Minerals: help carry out life functions. Minerals include calcium, phosphorus, magnesium, iron, and iodine
• Water: is essential for life because it is used in every life function. The water you take in through food and drink needs to balance the water that is eliminated from your body.
Canada’s Food Guide
Food Pyramid
10.2 Analyzing Diets
• Diet: the amount and type of food you eat
• Mixed diet: eating a wide variety of foods
• Canada’s Food Guide classifies food into four different groups
How much food do you need?
• The amount of food you need depends on:– Your age– Your body size– Your activity level– Your gender
Five guidelines
• Eat a variety of foods• Eat a lot of whole grain cereals, breads, fruits,
and vegetables• Choose low fat dairy products, lean meats,
and foods prepared with little or no fat• Participate in regular physical activity• Limit the intake of salt, sugar, alcohol, and
caffeine
Food Labels
• Advertising• Preparation directions• Nutrition information– Ingredients– Percentage of Recommended Daily Intake
Different types of diets
• Vegetarian• Vegan• Raw food• Paleolithic• Fads
Cleanses
• To give your body a break and deal with excess toxins
• May feel more fatigued during a cleanse
Lab
• Liver friendly foods
Liver-friendly foods
• Apples• Grapefruit• Broccoli
Apples
• Stimulate saliva to prevent tooth decay• Detox liver• Fibre– Controls weight– Avoid hemorrhoids– Prevent gallstones– Reduce cholesterol for a healthier heart
Grapefruit
• Detoxify liver• Strengthen immune system• Reduce risk of kidney stones• Boost metabolism• Fight gum disease• Prevent cancer• Reduce stress• Antioxidant• Vitamin C
Broccoli
• Detoxify liver by stimulating it with a toxin• Reduce osteoarthritis• Reduce cancer risk
10.3 Digestive System: Mining the Nutrients
Page 207
• Mechanical Digestion: teeth and stomach break food into small pieces
• Chemical Digestion: chemicals known as enzymes break down food particles
• Absorption: molecule-sized products move into blood stream
Digestive System
• Food = chemical energy• Body uses nutrients for energy, growth, and
repair• Different nutrients are digested in different
areas
Location of Digestion
• carbs: saliva, small intestine
• proteins: stomach• fats: small intestine• water and chemicals:
absorbed from stomach and in large intestine
More on nutrition in Chapter 10
• carbohydrates (sugars and starches)
• proteins• fats• vitamins• minerals• water
Nutrients
Digestive System• Mouth– mechanical digestion and saliva
• Esophagus– Transport by peristalsis
• Stomach– Stomach acid for protein digestion
• Small Intestine– With help from the pancreas, bile duct and gall bladder– Absorption of nutrients by microvilli
• Large Intestine– Final absorption of nutrients and water
Digestion: Mouth
• Teeth for mechanical digestion• Saliva for chemical digestion of starches
(carbohydrates)
Mouth
• Chewing: mechanical digestion • Saliva contains amylase, an enzyme that
breaks down carbohydrates• Creates a bolus to be swallowed
Digestive System
Esophagus
• Transport• Peristalsis
Digestive System
Stomach• Sphincters• Gastric juice containing enzymes and acid• Hydrochloric acid (HCl) is very strong acid
Digestive System
Digestion: Stomach
• Moves and mixes contents for mechanical digestion
• Mixes food with gastric juices (stomach acid) to form a pasty fluid
• Enzymes digest proteins to amino acids
Small Intestine• Duodenum where stomach acid is neutralized• Digest carbs, proteins, and fats
Digestive System
Digestion: Small Intestine
• Enzymes for chemical digestion only• Absorption of nutrients by microvilli
Small intestine• Carbohydrates: enzymes further break down
carbohydrates into sugars. These sugars are in a form that can be absorbed as the liver and pancreas neutralize the gastric juices
• Protein: enzymes split the proteins into simpler components (amino acids) into the bloodstream
• Fat: the liver produces bile which breaks fat into smaller particles. Enzymes from the pancreas can digest these smaller particles. Then fats can be absorbed
Large Intestine• Absorption of water, vitamins, minerals• Storage then elimination/excretion of waste• Feces are mostly dead bacteria and
undigested food, like fiber
Digestive System
Digestive System Summary:• Mouth– mechanical digestion and saliva
• Esophagus– Transport by peristalsis
• Stomach– Stomach acid for protein digestion
• Small Intestine– With help from the pancreas, bile duct and gall bladder– Absorption of nutrients by microvilli
• Large Intestine– Final absorption of nutrients and water
10.4 The Role of Diet
• What role does diet play in your life?
Evaluate Your Choices
• Do you think you eat a healthy diet?• Is your diet balanced?• Do you skip meals?
Choosing too many fats
• Your body has to work harder to digest fats• Excess fats in your digestive system may cause
you to feel uncomfortable or to throw up• High fat diets can cause fatigue and lack of
energy• Cholesterol from fatty foods blocks arteries• Over time, fats cause weight gain
Atherosclerosis
• Bad cholesterol LDL• Good cholesterol HDL
• Plaque that blocks the arterieshttps://www.youtube.com/watch?v=fLonh7ZesKs
• Bad for health• Can cause stroke and heart attack
Saturated fats
• Saturated fats are BAD• Trans-fats are sometimes bad• Unsaturated fats are GOOD
What is healthier?
• Burger, fries, milkshake
• Spaghetti, salad, glass of milk
This or That Trivia
White Meat or Dark Meat
French fries or Fried Potatoes
Fruit Punch or Cranberry Juice
Fruit Cup or Fresh Fruit?
Butter or Margarine?
Debatable! … Just reduce your intake of any butter or margarine