Transcript Nutrition Chapter 1 Inroduction to Nutrition

Introduction to Nutrition
Chapter 1
Learning Objectives
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Explain what nutrition is and why it should be important to
you on a personal level, and as a culinary/foodservice
professional.
Identify three food groups we don’t eat enough of, and two
food groups we eat too much of.
Define flavor and explain how it involves all five senses.
Discuss five factors that influence what you eat.
Define kilocalories; identify the three factors that influence
the number of kcalories you use every day; and explain the
effect of the following on basal metabolic rate: gender,
age, exercise, and growth.
Name the six classes of nutrients and their characteristics.
Learning Objectives (cont’d)
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Give two examples of foods that are nutrient dense and two
that are empty kcalorie foods. Explain why you chose these
foods.
Describe four characteristics of a nutritious diet.
Identify a given food as a whole food, processed food,
enriched or fortified foods, and/or organic food.
Explain what is meant by Recommended Dietary Allowance,
Adequate Intake, and Tolerable Upper Intake Level of a
nutrient.
Explain how food is digested and absorbed in the
gastrointestinal tract.
To run a sustainable facility, list five things chefs are doing in
the kitchen and five things managers are doing in the dining
room and production areas.
Nutrition and You
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More then just diet
◦ Must also maintain a healthy weight, engage in physical activity,
get enough sleep and not smoke
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Nutrition
◦ The science that studies how nutrients interact with your body,
physically and mentally
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Nutrients
◦ the nourishing substances in food that provide energy and
promote the growth and maintenance of the body.
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Looks at how nutrients and other substances in food
relate to health and disease.
Explores why you choose the foods you do – in other
words, the type of diet you eat.
Diet and Disease
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Our choice of diet strongly influence whether we will get
certain diseases such as:
◦ Heart disease
◦ Cancer
◦ Stroke
U.S. Epidemic: Overweight and Obesity
◦ 72% of men and 64% of women are overweight or obese.
◦ 32% of children ages 2 to 19 years are overweight or
obese.
Diet and Disease
What contributes to obesity? Diet and inactivity.
 What can obesity lead to? Diabetes, heart disease, high
blood pressure.
 Eating healthy can reduce your risk of:
◦ Heart disease
◦ High blood pressure
◦ Diabetes
◦ Several types of cancer
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Healthy Foods*
Fruits
Vegetables
Whole grains Beans and peas
Fat-free of low-fat
dairy
Lean meats,
poultry
Seafood
* All with minimal solid fat, sugar, or sodium
Nuts and seeds
How the US Diet
Compares to Recommendations
Why You Eat the Foods You Do
Flavor
 Other aspects of food (cost, convenience, nutrition)
 Demographics
 Culture and religion
 Health
 Social and emotional influences
 Marketing and the media
 Environmental concerns
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Flavor
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Includes taste, smell, texture or mouthfeel, temperature,
and sounds.
Flavor is a combination of all five senses (taste, smell,
touch, sight, and sound).
The most important consideration when choosing
something to eat is taste.
◦ You have about 10,000 taste buds on your tongue, cheeks,
throat, and roof of the mouth.
◦ Taste buds for each sensation are scattered around the mouth.
◦ Children under six have more taste buds, and adults over 50 start
to lose taste buds.
◦ Young children have more taste buds, so they can often be picky
eaters.
Five Primary Taste Sensations
Sweet
Sour
Salty
Bitter
Umami
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Umami
◦ Umami provides a savory, sometimes meaty, sensation.
◦ Umami taste receptor is very sensitive to glutamate—an
amino acid found in protein such as meat, fish, and milk,
and in the flavor enhancer MSG.
◦ Umami flavor increases when salt is added (ketchup, soy
sauce, fish sauce).
The heat of hot peppers is felt not by the taste buds but by
pain receptors in the mouth that sense heat.
Smell
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Smell is very important to taste.
◦ Most of taste is actually based on what we smell
◦ This explains why when we are stuffy, we cannot taste
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Receptors in your nose can distinguish among about
10,000 scents.
Texture or Mouthfeel
Textures that people like:
 Crispy
 Juicy
 Creamy
 Tender
 Firm
 Crunchy
Textures people generally
don’t like:
 Tough
 Crumbly
 Lumpy
 Soggy
 Watery
Textures influence whether you like the food, and
also tells you whether the food is fresh.
Sight and Sound
You eat with your eyes.
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Color is very important
◦ it tells you about the flavor and quality of food.
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For eye appeal, consider color, size, shape, consistency,
and arrangement.
Eye appeal is especially important for cold foods.
◦ Cold numbs the taste buds and therefore taste is muted
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Sounds—the sizzle of fajitas—stimulate appetite along
with sight.
Other Aspects of Food
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Food cost
◦ We live on a budget and prices can fluctuate
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Convenience
◦ Time is always a factor
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Availability
◦ Seasonal items
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Familiarity
◦ What we grew up eating
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Habits
◦ Cereal for breakfast, popcorn at the movies, chicken soup when
sick
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Nutrition
◦ Stronger nutritional labeling
Culture and Religion
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Culture is the behaviors and beliefs of a certain social,
ethnic, or age group
◦ What foods are eaten where, weddings
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Religion can affect day-to-day food choices.
◦ Kosher and Halal, Lent, etc
Other Influences on What You Eat
Health concerns (such as dieting)
 Social influences (peer pressure)
 Emotional influences (comfort foods)
 Marketing and the media
 Environmental concerns
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What are Kilocalories?
A measure of the energy in food
 One kilocalorie raises the temperature of one kilogram
of water one degree Celsius.
 Abbreviated as kcalorie or kcal.
 When you hear “calorie,” it is really a kilocalorie.
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◦ 1 kilocalorie = 1000 calories
◦ If we were to use true “calories” the numbers would be
cumbersome to keep track of
 Instead of a 2000 kcal diet, we would have a 2,000,000 calorie diet
Number of Kcalories Needed
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The number of kcalories needed is based on three
factors:
1. Basal metabolism (about two-thirds of total energy
needs for individuals who are not very active)
2. Physical activity can range depending on activity
3. Energy used to digest and absorb food (about 10% of
total energy needs)
BMR depends on:
Gender
Height
Age
Temperature
Growth
Fever and stress
Exercise
Smoking and caffeine
Sleep
Physical activity accounts for 25 to 40 percent of your
total energy needs.
What Are Nutrients?
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Carbohydrates
(4 kcal/g)
Fats (9 kcal/g)
Proteins (4 kcal/g)
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Vitamins
Minerals
Water
No kcalories in vitamins, minerals, or water.
Alcohol supplies 7 kcal/g but is NOT a nutrient
because it does not promote growth or
maintenance of the body.
Macronutrients vs.
Micronutrients
Macronutrients
The body needs these in
greater amounts, usually
measured in grams or
ounces
 Carbohydrates
 Fats
 Proteins
Micronutrients
The body needs these in
smaller quantities, usually
measured in micrograms
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Vitamins
Minerals
Carbohydrates
A large class of nutrients, including:
◦ Sugars
◦ Starch
◦ Fibers
 Sugars and starches function as the body’s primary
source of energy.
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Fats and Oils
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Fats and oils provide a
rich source of energy.
Examples:
◦ Butter
◦ Margarine
◦ Vegetable oils
◦ Mayonnaise
◦ Salad dressings
Protein
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Only about 15% of total kcalories should come from
protein.
Protein is part of every cell, tissue, and organ in the
body.
Animal foods are good sources of proteins.
Proteins are present in smaller quantities in plant foods
such as grains, beans, and vegetables, but they are not
complete
Vitamins and Minerals
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Non-calorie nutrients found in a wide variety of foods
that are essential to:
◦ regulate body processes.
◦ maintain the body.
◦ allow growth and reproduction.
Water
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Inorganic nutrient that makes up just over half of the
body’s weight
Plays a vital role in all bodily and metabolic processes
◦ Supplies the medium in which chemical change of the body
occur
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Aids digestion and absorption, circulation, and
lubrication of body joints
Your body
is about
60% water
and 20% to
25% fat.
Essential Nutrients
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Essential nutrients either cannot be made in the body or
cannot be made in the quantities needed by the body.
◦ Examples are vitamins and minerals.
What is Nutrient Density?
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Nutrient density is a measure of the nutrients provided in
a food per kcalorie of that food.
◦ How many kcalories the food provides versus how many
nutrients it provides
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Empty-kcalorie foods provide few nutrients for the
number of kcalories they contain.
Characteristics of a Nutritious Diet
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Adequate
◦ Provides enough kcalories, essential nutrients and
fiber to keep a person healthy
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Balanced
◦ Provides kcalories, essential nutrients and fiber in
the right proportions
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Moderate
◦ Avoids excessive amounts of kcalories or any
particular food group
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Varied
◦ A wide variety of foods from each food group
How to Recognize Whole, Processed,
Fortified, and Organic Foods
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Whole foods: Foods pretty much as we get them from
nature (eggs, fresh fruits and vegetables, beans and peas,
whole grains, fresh meat, milk)
Processed foods: food prepared using milling, cooking,
freezing, canning, dehydrating, or culturing with
bacteria (bread, cookies, cereals, sauces, soups, baking
mixes, frozen entrees, pasta, snack foods)
Enrichment and Fortification
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Fortification: a food is fortified when nutrients are added
that were not present originally, or nutrients are added
that increase the amount already present.
◦ Example: calcium in orange juice
Enrichment: a food is enriched when nutrients are added
to replace nutrients that were lost in processing.
◦ Example: breads enriched with iron and
several B vitamins
Organic Foods
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Organic food is produced without using most:
◦ Conventional pesticides
◦ Petroleum-based fertilizers or sewage sludge-based
fertilizers
◦ Bioengineering
◦ Ionizing radiation
Organic farms must be inspected annually.
All organically raised animals may not be given
hormones or antibiotics, and must have access to a
pasture.
Labeling of Organic Foods
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100% organic
95% organic
These can use USDA
Organic seal.
70% organic ingredients:
These can use the phrase
“made with organic
ingredients.”
Digestion, Absorption, and
Metabolism
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Digestion: Process by which food is broken down into
its components in the gastrointestinal tract with the help
of digestive enzymes.
Absorption: The passage of digested nutrients through
the walls of the intestines or stomach into the blood,
where they are transported to the cells.
Metabolism: All the chemical processes by which
nutrients are used to support life.
◦ Catabolism- breaking down of substances
 Breaking sugar down to monosaccharaides
◦ Anabolism- building up of substances
 Building bone tissue
What Happens When You Eat?
The
Gastrointestinal
Tract
The Digestive System
Mouth –
Oral Cavity
• Tongue and teeth help chew food (32 adult
teeth)
• Saliva contains digestive enzymes and
lubricates the food to move further along
Tongue rolls chewed food into a ball to be
swallowed.
From Mouth • The food moves from the mouth through the
to Esophagus
pharynx to the esophagus.
• Peristalsis- involuntary motion
Stomach
• Food passes from esophagus into the stomach.
• Stomach holds about 4 cups of food.
• Makes hydrochloric acid that helps in protein
digestion and destroys bad bacteria.
• Fatty foods leave stomach after carbohydrates
and protein.
The Digestive System
Small
Intestine
• Nutrients are still being digested.
• Site of most nutrient absorption.
• Most nutrients pass through villi into blood
vessels—or are transported to the blood.
• Nutrients travel in the blood throughout the
body where they can enter the cells.
Large
Intestine
• Connects small intestine to the rectum.
• Receives waste products of digestion and
passes them on to rectum.
• Absorbs water, some minerals, and a few
vitamins (such as vitamin K) made by
bacteria residing there.