NTDT Chapter One: The Science of Nutrition

What is the leading cause of Death in the U.S?

Heart Disease

Nutrition

The science of food. The nutrients and the substances therein; the process by which the organism ingests, digests, absorbs, utilizes and secretes food.

Nutrients

Substances essential for health that the body cannot make or makes in quantities too small to support life.

What are the characteristics of an essential nutrient?

1. Has a specific biological function
2. Absence from the diet leads to a decline in biological function
3. Adding missing substances back to the diet before permeant damage occurs restores normal biological function

What are the energy yielding nutrients?

1. Carbs
2. Lipids
3. Fats

What are the nonenergy yielding nutrients?

1. Vitamins
2. Minerals

What are the functional categories of nutrients?

1. Provide energy: most carbs, proteins, most lipids
2. Promote growth and development: proteins, lipids, some vitamins and minerals, and water
3. Regulate body processes: proteins, some lipids, some vitamins, some minerals and water

What are macronutrients and examples?

-Nutrients needed in large amounts
EX: Carbs, lipids, proteins and water

What are micronutrients and examples?

-Nutrients needed in small amounts
EX: Vitamins, minerals

What are carbs made of and where can they be found?

-CHO
-Found in fruits, veggies, grains and beans
-4 kcal/gram
-Simple (table and blood sugar) complex (starch, glycogen and fiber)

What are Lipids made out of, what can they be found in and what are some characteristics of them?

-CHO
-Insoluble in water
-9 kcal/gram
Fats are lipids that are solid at room temperature
Oils are liquid at room temperature

What are triglycerides?

-Major form of fat in the body
-Major energy source for the body
-Composed of three fatty acids attached to a glycerol backbone

What is the difference between saturated and unsaturated fat?

Saturated:
-Mainly found solid at room temp
-Mainly found in animal sources
-Raise blood cholesterol levels
-Can lead to cardiovascular disease
Unsaturated:
-Mainly found in liquid at room temp
-Mainly found in plant sources
-Healthier than saturated fats

What are essential fatty acid?

Unsaturated fatty acids that must be supplied by the diet
-EX: Linoleic acid, Alpha-linoleic acid

What important roles do essential fatty acids have in the body?

-Being structural components of cell walls
-Regulating blood pressure
-Regulating nerve transmission
-Can be found in vegetable oil and fish

What are trans fatty acids?

-Unsaturated fats that have been processed from cis form to trans form
-Primary found in deep fried foods, backed snack goods, and solid fats
-pose a health risk
-Intake should be minimized

What are the main components of proteins and their characteristics?

-CHON
-Found in: Blood, bone, muscle, cell membranes. enzymes, immune factors, chicken etc.
-4 kcal/gram
-formed from bonding of amino acids

What is the main function of vitamins and its different forms?

-Function: enable chemical reactions to occur; helps release energy but does not provide energy
Fat soluble: A,D,E and K; more likely to accumulate and cause toxicity

Water soluble: Vitamin C and B; more likely to get destroyed while cooking, excreted from body more readily

What are minerals and their two major groups?

-Inorganic substances, not destroyed by cooking, yield no energy; required for normal body function

Major minerals: needed in gram amounts daily

Trace minerals: needed in less than 100 mg daily

What is are the functions of water and its characteristics?

-Needed in the largest quantity of all nutrients
-Several vital function: solvent, lubricant, transports nutrients, regulates body temperature
Sources: food and drink; byproduct of metabolism

What are phytochemicals and zoochemical?

Phytochemicals:
-Physiologically active compounds found in plants that may provide health benefits.
EX: Saponins (garlic, onion), Monoterpenes (oranges)
Zoochemical:
-Physiologically active compounds found in foods of animal origin that may provide health benefits.
EX: Sphingolipids (meat and dairy products)

Neither are considered to be essential nutrients.

What are functional foods?

Foods rich in phytochemicals and zoochemicals Provide health benefits beyond those supplied by the traditional nutrients it contains Functional Food

Categories:
-Conventional foods: unmodified whole foods
-Modified foods: fortified, enriched, or enhanced foods -Medical foods: food, formula, or supplement under medical supervision to manage a health condition
-Special dietary use foods: That help meet a special dietary need.

What are fermented foods and an example?

- Rely on bacteria, yeast or fungi to convert natural sugar or starch to acids which preserve the food.
-Can be used as a probiotic and may offer health benefits
EX: yogurt

What are fermented foods energy sources and uses?

-Energy is needed to perform body functions and do work.
-From carbohydrates, proteins, fats, and alcohol (non-nutrient)
-Measured in kilocalories (Calories)
-With energy, we can:
-Build new compounds
-Move muscles
-Transmit nerve impulses
-Balance ions within cells

What is a calories and a kilocalorie?

Calorie:
-Amount of heat energy needed to raise the temperature of 1 gram of water 1 degree Celsius.
-This is a tiny unit of measurement!
Kilocalorie:
-Amount of heat energy needed to raise the temperature of 1000 grams of water 1 degree Celsius.
-This is a more appropriate unit of measurement for energy found in food

What does the North American diet look like?

Surveys show that North Americans consume:
-16% of energy intake as proteins
-50% as carbohydrates
-33% as fats
Although these amounts are all within healthy ranges, many people are eating more than they need to maintain a healthy weight.

What is wrong with the north American Diet?

-Too many calories are being consumed
-Too much protein from animal sources; too little from plants
-Too many carbohydrates from simple sugars; too few from complex carbohydrates
-Too much fat from animal sources; too little from plants

How can the North American diet be imporved?

-Increase intake of foods rich in vitamins A and E, iron, and calcium
-Decrease intake of sodium
-Moderate intake of sugary soft drinks and fatty foods
-Eat more fruits, vegetables, whole-grain breads, and reduced-fat dairy

What is the difference between hunger and appetitite?

Daily food intake is a mix of our need to satisfy hunger and social and psychological needs.
Hunger:
The physical need for food.
Appetite:
The psychological desire to eat.

Appetite and food choice depend on many factors

What is a desirable health status mean?

Desirable (optimal) nutritional status: The body has enough to support normal functions and build surplus stores
-Adequate liver stores of iron, adequate blood levels of iron-related compounds, and normal functioning of red blood cells

What are the two forms of malnutrition?

Undernutrition:
-Nutrient intake does not meet needs
-Nutrient stores are depleted
-Subclinical: early stage of nutrient deficiency Decline -In iron-related compounds in the blood, which reduces the ability of the red blood cells to carry oxygen to body tissues and, in turn, causes fatigue on exertion, poor body temperature regulation, and eventually pale complexion
Overnutrition:
-Consumption of more nutrients than the body needs
-Most common type in industrialized nations: excess energy intake
-S+S: excess liver stores of iron, which damage liver cells

How can you assess nutritional status?

A nutritional assessment can help determine how nutritionally fit you are.
A nutritional assessment should include:
-Family history and self history
-Anthropometric assessment (e.g., height, weight, skinfold thickness, arm muscle circumference, body composition)
-Biochemical (laboratory) assessment (e.g., compounds in blood and urine)
-Clinical assessment (e.g., physical examination of skin, eyes, and tongue; ability to walk)
-Dietary assessment (e.g., usual food intake, food allergies, supplements used)
-Environmental assessment (e.g., education and economic background, marital status, housing condition)

What are the limitations of nutritional assessments?

-Many signs and symptoms of a deficiency are not very specific:
-Diarrhea, skin conditions, fatigue
-It may take a long time for the signs and symptoms and the clinical evidence of a nutritional deficiency to develop.
EX: Osteoporosis developing later in life although deficiency of calcium may have begun in teen years

What is the importance of being concerned about your nutritional status?

- Increased likelihood of enjoying a long, vigorous life and less likely to develop health problems
-EX: Women following a healthy lifestyle had an 80% reduction in risk of heart attacks:
-Varied diet, rich in fiber, and low in animal and trans fat, and included some fish
-Avoided being overweight • Regularly drank a small amount of alcohol
-Exercised for 30 minutes daily
-Did not smoke

What is the nutrition care process and its steps?

A registered dietitian nutritionist (RDN) will follow the Nutrition Care Process They should:
-Conduct a nutrition assessment
-Diagnose nutrition-related problems
-Create an intervention
-Monitor and evaluate progress

How does our genetics play a role in our nutrition?

Our genes, as well as our lifestyle and diet, affect our health.
-DNA directs how the body uses the nutrients consumed.
-Genes dictate how nutrients will be transformed and reassembled into body structures and compounds.
-Individual genetic risks of a disease are an important factor in determining whether that individual develops a disease
-A mutation is a change in the sequence of the DNA that may increase the risk of certain diseases

What nutritional disease have a genetic link/ are hereditary?

Family history is considered one of the most important risk factors in the development of many nutrition-related diseases:
-Diabetes
-Cancer (breast, colon, and prostate)
-Osteoporosis
-Cardiovascular disease
-Hypertension
-Obesity

How can you exert some control over your diet to avoid hereditary nutritiona diseases?

Heredity is not destiny. Individuals can exert some control over the expression of their genes.
Example: If you have a predisposition to premature heart disease, you can delay its onset by:
-Eating a nutritious diet.
-Regularly exercising.
-Controlling your weight.
-Getting medical treatment.

How can you asses your risk for a nutritional disease?

-Assess your risk by creating a family tree of illnesses and deaths.
-High -risk conditions include having more than one first -degree relative with a specific disease

What is gene therapy and is it approved by the FDA?

-Scientists are developing therapies to correct damaged DNA that causes some genetic disorders.
-Normal DNA is isolated.
-Normal DNA is packaged into a molecular delivery vehicle (virus).
-Delivery vehicle is injected into affected cells
-Normal genetic material begins to function. Gene therapy is not yet approved by the FDA.

What is genetic testing and how can it be used?

-Genetic tests analyze a person's genes to determine the likelihood of developing diseases.
-Can be helpful for families afflicted by certain diseases -Recommended to have a genetic counselor evaluate your risk first
-May be done with or without your physician (at home testing is available)

What are the limitations of genetic testing?

-Not possible to identify all people at genetic risk for diseases
-Genetic susceptibility does not guarantee development of a disease
-No way to cure a genetic alteration; can only treat health problems

What is the scientific method and how can it be used to access your diet?

-The research that sets the foundation for nutrition has developed through the use of the scientific method
- The scientific method is a testing procedure designed to uncover facts and detect and eliminate errors.
-This is done by conducting controlled experiments to test hypotheses.
-Research requires an open, curious mind and a questioning, skeptical attitude.
1. Observe, 2. hypothesize, 3. research experiments conducted, 4. findings evaluated by other scientist, 5. follow up experiments, 6. accept or reject hypothesis

What are la animal experiments?

-Laboratory animals are used when scientists cannot test their hypothesis on humans.
-Use of laboratory animal experiments depend on the availability of an animal model

What are human experiments?

-Must be approved by a research review board Requires the researchers to obtain informed consent from participants indicating they understand the study's purpose, procedures and known benefits and risks prior to participating. Experimental approaches used: • -Migrant studies
-Cohort studies
-Case control
-Double-blind studies

What are case control studies?

Individuals who have the condition (case) are compared to those that do not (controls). Strongest studies compare groups that are similar in:
-Age
-Race
-Gender Limitation: Cannot claim cause and effect

What is a blind study?

-Gives more definitive testing of a hypothesis -Experimental group follows a protocol Control group usually receive a placebo In a single-blind study only the participant does not know who is receiving the placebo or the treatment. To help reduce bias:
-Neither study participants nor researchers know who is in which group (double-blind)
-Expected effects of protocol are not disclosed reducing the chance of a placebo effect.

What is the peer review process of experimental results?

Prior to publishing, other scientists review study
-Ensures most unbiased, objective findings are published to peer-reviewed journals:
-American Journal of Clinical Nutrition
-New England Journal of Medicine
- Journal of the Academy of Nutrition and Dietetics

What are follow-up studies?

One experiment is not enough to accept a hypothesis. Results must be confirmed by more experiments. The more evidence supporting a hypothesis, the more likely it is true.

What are systemic reviews?

-Critical evaluation and synthesis of research studies focusing on a specific topic or research question
-Used to help determine which clinical methods are likely to help patients • Organizations:
-Evidence Analysis Library (EAL)
-U S D A Nutrition Evidence Library
- E-Library of Evidence for Nutrition Actions (eLENA)
-The Cochrane Collaboration

How do you properly evaluate Nutrional claims?

.1. Apply the basic principles of nutrition.
2. Be wary of a claim when:
-Only advantages are discussed
-New or "secret" breakthrough
-Claims to "cure" a disease
-Sounds too good to be true
-Extreme bias against medical community
3. Examine the scientific credentials of the individual or organization.
4. Look at the research behind these claims?
-Size of study
-Duration of study
-Type of study
5. Be wary of press conferences and other hype.

What does the FDA do?

-The Dietary Supplement Health and Education Act (DSHEA) of 1994 classified vitamins, minerals, amino acids, and herbal remedies as "foods."
-FDA must prove these products are unsafe to prevent sale.
-A product labeled as a dietary supplement can be marketed in the U.S. without FDA approval.

Why is it important to buy nutrition related products?

To protect your health:
-Scrutinize nutrition-related product labels.
-Be sure there is scientific proof supporting claims.
-Do not use products for purposes not stated on label. The labels are allowed to claim:
-General well-being results
-How product provides benefit
-How it will affect bodily structure or function