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Chapter 1- Nutrition, Food for Health
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How healthy is the typical American diet?
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Does not align with recommended limits or goals. Americans eat excessive
amounts of energy-dense foods and insufficient amounts of nutrient-dense foods.
Processed and convenience foods:
● are easily obtainable but may not provide the necessary nutrients.
● contain an elevated level of calories, sodium, and fat.
50% of the population.
● does not consume sufficient amounts of foods that provide necessary nutrients.
Classes of nutrients
● Macro and Micronutrients
● Essential nutrients are nutrients we need that we can’t make enough. “YOU
HAVE TO EAT IT TO GET IT.”
● Macronutrients consist of Carbohydrates (4 cal/gm), Protein (4 cal/gm), and
Fat (9 cal/gm); Micronutrients consists of vitamins and minerals.
Classes of nutrients: macronutrients
● Macronutrients are needed in the body in Large amount each day.
● The amount of energy is measured in Kilocalories
● Kilocalorie is abbreviated calorie or kcal.
Energy-yielding nutrients:
● Energy-yielding nutrients include carbohydrates (58% required daily), proteins
(12% required daily) and fats (30% required daily).
● Energy-yielding nutrients are also called macronutrients.
Macronutrients provide energy…
● Macronutrients provide energy to the body
Carbohydrates include sugars…
● Carbohydrates include sugars and starches.
Fiber belongs in the category…
● Fiber belongs to the category of carbohydrates but does not provide energy.
Classes of macronutrients: Lipids
● Lipids are “fats” and “oils”.
● Lipids are a concentrated form of energy.
● Lipids = the most energy dense or most calories per gram of all macronutrient
● Triglyceride the main type of fat that is found abundant in the body. Lipids
contain 9 kcalories.
Classes of nutrients: Proteins
● Proteins are required for growth, maintenance and repair of the body.
● Proteins contain 4 kcalories/gram
● Proteins can also supply energy.
● Meat, fish, poultry, dairy products, legumes, and grains can provide protein
● Proteins are made of different combination of amino acids.
● Hemoglobin is a protein found in Red blood cells.
Classes of nutrients: micronutrients
● Micronutrients include vitamins and minerals.
Classes of nutrients: Water
● Water makes up approximately 60% of the healthy human body
Regulating body processes
● All the reactions that occur in the body are called metabolism.
● Water helps to regulate temperature.
● Protein, vitamins, and minerals help to speed up or slow down metabolic
reactions.
Nutrient intake and health: Food availability
● Geography
● Transportation and Mobility
● Available income
● Food storage and preparation equipment
Cultural and personal background
● Religious dietary laws
● Ethnic menu Preferences
● Social acceptability
● Personal preference
● Psychological and emotional factors
● Health concerns
The Scientific Method
● Advances in nutrition are made using the scientific method.
● The scientific method uses an unbiased approach to examine the interaction of
food, nutrients, and health.
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The steps in the scientific method are observation, hypothesis,
theory.
What makes a good experiment?
A well-conducted experiments requires:
● Quantifiable Data
● Appropriate Experimental Population
● Proper Controls
Ways to maintain Proper Control:
● Control groups act as a standard comparison.
● Placebos are identical in appearance to the actual treatment but no therapeutic
value.
● Single blind study: subjects do not know which treatment they are receiving.
● Double-blind study: neither the subject nor the investigators know which
treatment is being received.
● The peer review system allows for scientific interpretation of experimental
results. Research is published in peer review journals and other legitimate
publications so other professionals can refer to them and critique.
Types of nutrition research studies
● Observational studies can include epidemiology and correlation.
● Human intervention studies are also known as clinical trials.
● Laboratory studies are conducted in research facilities such as hospitals or
universities.
Human intervention studies are also known as clinical trials.
Identifying reliable nutrition information
● Does the information make sense?
● Where did the information come from?
● Is the information based on well-designed, accurately-interpreted research
study?
● Who will benefit when you purchase this product?
● Has this product stood the test of time?
Where did the information come?
● Published in peer-reviewed journals and other legitimate publications so other
professionals can refer to them and critique.
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Chapter 2- Nutrition Guidelines
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Applying the Science of Nutrition: Dietary reference intakes
The original dietary standards were the RDAs (Recommended Dietary Allowances)
DRIs have been developed for five (5) nutrient group:
1. calcium, phosphorus, magnesium, vitamin D and fluoride = for bones
2. B vitamins (eg. folic acid) and choline = for metabolic processes
3. vitamin C, vitamin E, selenium (mineral) and beta-carotene (vitamin A) =
are antioxidants (enzymes) that help fight free radicals.
4. Energy and macronutrients = provide energy or calories
5. Electrolytes and water = electrolytes are minerals like calcium, potassium,
sodium, chloride
The DRI’s need not be consumed every day but should be consumed on most days, as
an average intake.
Food values
● Food labels list the amounts of certain macro and micronutrients.
● These nutrients are expressed as Daily Value.
Daily value is the amount of a nutrient in a food shown as a percentage of the
recommendation for a person consuming 2000 kcalorie diet.
Exchange List for Meal Planning
● The Exchange Lists for Meal Planning is a food group system used to plan
diets and menus to meet specific energy and macronutrient needs.
● Developed by the American Dietetics Association and American Diabetes
Association.
● Can be used to plan weight loss, weight gain and healthy diets
Assessing Nutritional Health
● Nutritional assessments can help individuals determine if their intake is healthy.
Dietary intake can be assessed through:
❏ 24 hour recall
❏ Food diary or food intake record
❏ Food frequency questionnaire
❏ Diet history
Analyzing Nutrient Intake
● To get a generalized nutritional “snapshot”, individual nutrient intake can be
compared to recommended intakes.
Nutrient analysis tools can include:
● MyPyramid
● Food labels
● Nutrient content tables
● Computer programs
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Chapter 3- Digestion, Absorption, and
Metabolism
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Overview of the digestive system
● Digestion inside the G.I. tract is assisted by digestive secretions.
● Mucus: material produced by the goblet cells. Mucus moistens, lubricates and
protects the G.I. tract.
● Enzymes: protein molecules that speed up chemical reactions. Enzymes are not
changed during reactions.
Digestion and absorption
The mouth is the entry point for food into the digestive tract.
● Saliva contains Salivary Amylase which helps to breakdown carbohydrates,
and Lysozymes which help to inhibit bacterial growth in the mouth.
The brain is involved in digestion and absorption.
● The brain's response to sights and sounds of food is called the Cephalic
Response.
The gallbladder, liver, and pancreas (accessory organs) are involved in digestion
and absorption.
● The Liver produces bile then secretes it to the gallbladder where it is stored.
● The Gallbladder releases bile to the small intestine.
● The Pancreas produces enzymes and hormones which help with digestion. The
pancreas also secretes bicarbonate ions which neutralize the acid from the
stomach and small intestine.
Water, nutrients and fecal materials may spend up to 24 hours in the large intestine.
Transport of nutrients
Absorption is when nutrients are absorbed from the small intestine into the blood or
lymph. They are transported by one of 3 (three) ways:
1. Diffusion: where molecules such as water can flow across a membrane through
osmosis.
2. Carrier transport: where molecules have to be carried across the a membrane
by a protein transport molecules.
3. Active transport: where molecules have to be carried across a membrane by a
protein transport molecule and require energy
The primary energy source used in the body is ATP (Adenosine Triphosphate)
The hepatic portal Circulation
● Once the nutrients are in the blood, they move via the hepatic portal vein to the
liver.
❖ The prefix Hep often refers to the liver.
❖ The liver determines nutrient needs.
Metabolism of nutrients
Catabolic pathways release energy...
Elimination of metabolic wastes
● The body gets rid of the waste products through several means:
— exhaling (respiratory system)
— feces (digestive system)
— sweat (integumentary system)
— urine (urinary system)
The Kidneys are essential organ for elimination.
— The kidneys filter metabolic waste products out of the blood