Wardlaw's Perspectives in Nutrition Ch. 1

Nutrition

the science of food; the nutrients and the substances therein; their action, interaction, and balance in relation to food and disease; and the process by which the organism ingests, digests, absorbs, transports, utilizes and excretes food substances.

Essential Nutrient

substance essential for health that the body cannot make or makes in quantities too small to support health. (About 50 considered essential)

3 criteria for determining essential nutrients

1. It has to have a specific biological function (can test for it)

2. Removing it from the diet leads to decline in human biological function

3. Adding the original substance back before permanent damage occurs restores biological function to normal.

Functional Categories of Nutrients

1. Those that primarily provide energy (Macro)

2. Those that are important for human growth and development and later maintenance

3. Those that keep the body running smoothly.

6 categories of nutrients

Macro: 1. Carbohydrates 2. Proteins 3. Lipids 4. Water

Micro: 5. Vitamins 6. Minerals

Macro vs Micro Nutrients

Macro= needed in large amounts

Micro= needed in small amounts

Functional Nutrients - Energy Providing

1. Most carbohydrates

2. Proteins

3. Most lipids (fats and oils)

Functional Nutrients- Promote Growth and Development

1. Proteins

2. Lipids

3. Some vitamins

4. Some minerals

5. Water

Functional Nutrients- Regulates Body Process

1. Proteins

2. Some lipids

3. Some vitamins

4. Some minerals

5. Water

Leading Causes of death in US? Which ones does diet play a role?

1. Heart Disease (Diet related)

2. Cancer (Diet related)

3. Cerebrovascular Disease (stroke) (Diet related)

4. Chronic Obstructive Lung Disease

5. Accidents

6. Diabetes (Diet related)

7. Influenza and Pneumonia

8. Alzheimers (Diet related)

9. Kidney Disease (Diet related)

10. Blood borne infections

11. All other deaths

How in energy measured in food?

Kilocalorie (kcal); the amount of heat energy it takes to raise the temperature of 1000g of water 1 degree. Generally written calorie with a little c. Any calorie on a food label (even written with a big c) is a kilocalorie.

What are the values of energy yielding food, including alcohol?

Carbohydrates: 4 g

Proteins: 4g

Lipids: 9g

Alcohol: 7g

Organic vs Inorganic (nutritional science)

Organic: contains carbon atoms bonded to hydrogen atoms in the chemical structure.

Inorganic: DOES NOT contain carbon atoms bonded to hydrogen atoms in the chemical structure.

Primary Food Sources of Carbohydrates

Primary sources: Fruits vegetables, grains, and beans.

Subcategories of Carbohydrates

Simple: table sugar (sucrose), blood sugar (glucose), fruit sugar (fructose), milk sugar (lactose)

Complex (polysaccharides): starch in grains, glycogen in our muscles, potatoes., legumes, fiber.

Proteins

Formed by the bonding of amino acids (sub-unit). Contain nitrogen in addition to the carbon, hydrogen and oxygen. Main structural material in the body; components in blood, cell membranes, enzymes, and immune factors.

Lipids. Two common names of fats we eat? Unhealthy fat that should be avoided?

Triglycerides: Major form of fat in food, key energy source and fat storage in our bodies. Made up of fatty acids and glycerol. More bonds to break so great for energy.

Essential Fatty Acids: Linoleic Acid and Linolenic Acid.

Avoid Trans fatty Acids

Water soluble vitamins

-9 total: Vitamins C and B complex (thiamin, riboflavin, niacin, B-6, pantothenic acid, biotin, folate, and B-12)

-More easily excreted from the body via the kidneys/ urine

-Easily destroyed by cooking

-Will tend to stay in water compartments in the body like the blood.

Vitamins

Enable chemical reactions. Provide no usable energy. 13 known essential vitamins- all are organic, 9 are water soluable

Fat Soluble vitamins

A,D,E,K.

-Have to bind to fat in order to be absorbed.

-Will travel to and store in fatty tissues (fat and water don't mix well)

-Liver is a fatty tissue that can collect and store

- More easily stored in the body, therefore greater risk of toxicity.

Minerals

Inorganic compounds required for body function.

Work in groups of one or more of same atoms (sodium or potassium); or as mineral combinations (calcium with phosphorous compound found in bones)

Can't be destroyed during cooking

Yield no energy. Required for body functions (nervous, skeletal and water balance).

Major Minerals

>100mg required daily

Sodium, Potassium, Chloride, Calcium, Phosphorous

Trace Minerals

<100mg daily required daily

Iron, Zinc, Copper, Selenium

Phytochemicals and Zoochemicals

Functional Foods. Physiologically active compounds NOT essential. In unmodified whole foods. Thought to have health benefits. Foods modified or fortified with phytochemicals also beneficial. Phyto - plant. Zoo- animal.

Phyto: tomato, plant stanols, fruits, vegies, whole grains, legumes; Zoo: fatty fish omega 3 fatty acids, probiotics.

Factors that affect our food choices

Hunger (physical need) vs appetite (psychological desire to accept or reject certain foods)

-flavor, texture or appearance

-culture

-lifestyle

-routines and habits

-food cost and availability

-environment

-food marketing

-health and nutrition concerns, knowledge and beliefs

Energy Uses of Energy Producing Nutrients

Heat Production

Build new compounds

Perform Muscular Movements

Promote Nerve Transmission

Maintain Ion Balance w/ cells- electrolytes

Undernutrition vs Overnutrition

Both malnutrition

Subclinical undernutrition: developing but signs not noticable yet (no overt signs)

Clinical undernutrition: sign can be seen: flaky skin; symptom: change in bodily function not necessarily apparent

Overnutrition: Toxicity or Obesity (excess energy nutrients)

Nutritional Assessment (A,B,C,D,E)

Anthropometric (measurement: height, weight, inches)

Biochemical: concentration of nutrients in blood, feces, urine, enzyme levels

Clinical: Exam for physical evidence of deficiencies

Dietary: food history, 24 hr recall, etc

Environmental: education and economic background

Limitations of Nutritional Assessment

-Many signs and symptoms are not very specific- could be nutritional or unrelated (diarrhea, skin or fatigue)

-Signs and symptoms can take a long time to develop and can seem vague

-A long time between development and clinical evidence (i.e. high cholesterol building to artery issues)

Healthy People 2020

Report issued in 2010 by DHHS, Public Health Service. Provides 10 year goals for improving health.

Main objectives: to help all people attain high-quality, longer lives free of preventable disease, disability, injury, and premature death.

Scientific Method in field of nutrition

1. Observation made and questions asked

2. Hypothesis Generated

3. Research experiments conducted

4. Findings evaluated by other scientists and published

5. Follow up experiments to confirm or extend finding

6. Accept or reject hypothesis

1. Epidemiological studies

2. Case-control studies

3. Migrant Studies

4. Double Blind

5. Placebo Effect

1. The study of disease populations

2. Individuals with like characteristics with disease compared to those without disease.

3. Changes in health of people who move from one place to another.

4. Participants receiving treatment and those who receive placebo. All parties (patients and doctors) unaware of who is in which group.

5. Participants feeling better or improving simply because they are in a study or receiving a new/ different treatment- even when not the actual new drug/ treatment being studied.

Benefits of animal model

A disease in laboratory animals that mimics a human disease. Used when unethical to conduct research on human models. Much of what we about human nutritional needs generated from lab animal experiments. (Most human chronic diseases do not occur in laboratory animals.)

Peer review

Before results published, critically reviewed by other scientists familiar with the subject. Objective is to ensure only the most unbiased, objective findings from carefully designed and executed research studies are published.

Reliable Sources of Nutritional Information

Apply basic nutrition principals

Evaluate the claims critically

Examine the scientific credentials of author

Examine the study cited (published? reputable journal?)

Beware of hype

Supplements

DSHEA (Dietary Supplement Heath and Education Act of 1994). Supps do NOT require FDA approval. Do NOT need to be proven effective if "reasonably safe" with a history of use.