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