1. The Role of Nutrition in Our Health1
The Role of Nutrition in Our Health

2. What Is Nutrition? Food refers to plants and animals we eat
Nutrition is the science that studies food:
How food nourishes our bodies
How food influences our health

3. Why Is Nutrition Important?
Proper nutrition supports wellness
Wellness is more than the absence of disease
Physical, emotional, and spiritual health
Active process
Critical components of wellness
Nutrition
Physical activity

4. Why Is Nutrition Important?
Healthful diet can prevent disease
Poor nutrition causes deficiency diseases: scurvy, pellagra
Nutrition plays a role in osteoporosis and cancer
Nutrition is associated with chronic diseases: heart disease, stroke, and diabetes

5. Why Is Nutrition Important?
Obesity is a growing problem:
Eating more calories than expended
Risk factor for heart disease, stroke, type 2 diabetes, and some forms of cancer

6. Why Is Nutrition Important?
Nutrition is a national goal to promote optimal health and disease prevention
Goals of Healthy People 2020
Increase quality and years of healthy life
Eliminate health disparities

8. What Are Nutrients?
Nutrients are chemicals in foods that our bodies use for growth and function
Organic nutrients contain carbon, an essential component of all living organisms
Carbohydrates, lipids, proteins, vitamins
Inorganic nutrients: nutrients that do not contain carbon
Minerals and water

9. Determining Nutrient Needs
Dietary Reference Intakes (DRIs): updated nutritional standards
Expanded on the traditional RDA values
Set standards for nutrients that do not have RDA values
Dietary standards for healthy people only
Aim to prevent deficiency diseases and reduce chronic diseases

10. Determining Nutrient Needs
Dietary Reference Intakes (DRIs) consist of:
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
Dietary Reference Intakes (DRIs) Determination

11. Determining Nutrient Needs
Estimated Average Requirement (EAR)
The average daily intake level of a nutrient to meet the needs of half of the healthy people in a particular life stage or gender group
Used to define the Recommended Dietary Allowance (RDA) of a nutrient

12. Determining Nutrient Needs
Recommended Dietary Allowance (RDA)
The average daily nutrient intake level that meets the needs of 97% to 98% of healthy people in a particular category

13. Determining Nutrient Needs
Adequate Intake (AI)
Recommended average daily nutrient intake level
Based on observed and experimentally determined estimates of nutrient intake by a group of healthy people
Used when the RDA is not available: calcium, vitamin D, vitamin K, and fluoride

14. Determining Nutrient Needs
Tolerable Upper Intake Level (UL)
Highest average daily nutrient intake level likely to pose no risk of adverse health effects to most people
Consumption of a nutrient at levels above the UL increases the potential for toxic effects and health risks increases

15. Determining Nutrient Needs
Estimated Energy Requirement (EER)
Average dietary energy intake to maintain energy balance in a healthy adult
Defined by age, gender, weight, height, and level of physical activity

16. Determining Nutrient Needs
Acceptable Macronutrient Distribution Ranges (AMDR)
Ranges of energy intakes from macronutrients that are associated with reduced risk of chronic disease while providing adequate intakes of essential nutrients
If nutrient intake falls outside this range, there is a potential for increasing our risk for poor health

18. Assessing Nutritional Status
Nutrition professional must have a thorough understanding of the client’s current nutritional status
Weight
Ratio of lean body tissue to body fat
Intake of energy and nutrients
Foundation of recommended dietary and lifestyle changes
Baseline for evaluation

19. Malnutrition
Nutritional status is out of balance: too much or too little of a particular nutrient or energy over a significant period of time
Undernutrition: too little energy or too few nutrients over time, causing weight loss or a nutrient-deficiency disease
Overnutrition: too much energy or too much of a given nutrient over time, causing obesity, heart disease, or nutrient toxicity

20. Physical Examinations
Physical exams are conducted by trained healthcare providers
Tests depend upon client’s medical history, disease symptoms, and risk factors
Typical tests include vital signs, lab tests, heart and lung sounds
Nutritional imbalances may be detected by examining hair, skin, tongue, eyes, and fingernails

21. Health History Questionnaire
Tool to assist in cataloging history of health, illness, drug use, exercise, and diet
Socioeconomic factors (education, access to shopping/cooking facilities, marital status, ethnic/racial background)
Energy and nutrient intake questionnaires

22. Dietary Intake Tools Techniques to assess nutrient and energy intakes:
Diet history
Twenty-four-hour dietary recall
Food frequency questionnaire
Diet records
Strengths and limitations

23. Diet History Information from interview or questionnaire:
Weight (current and usual weight, goals)
Factors affecting appetite and food intake
Typical eating pattern
Disordered eating behaviors (if any)
Education and economic status
Living, cooking/food purchasing arrangements
Medication and dietary supplements
Physical activity

24. Twenty-Four-Hour Dietary Recalls
Recalls all food and beverages consumed in the previous 24-hour period
Accurate recall includes serving sizes, food preparation methods, and brand names of convenience foods or fast foods
Limitations:
May not be typical intake
Relies on memory
Relies on ability to estimate portion sizes

25. Food Frequency Questionnaires
Determine typical dietary pattern over a predefined period of time
Include lists of foods with the number of times these foods are eaten
Some assess only qualitative information (typical foods without amounts)
Semiquantitative questionnaires assess specific foods and quantity consumed

26. Diet Records
List of all foods and beverages consumed over a specific time period (3−7 days)
Improved accuracy when:
Foods are weighed or measured
Labels of convenience foods and supplements are saved
Challenges to accuracy and sufficient detail

27. Anthropometric Assessment
Common measurements include height, body weight, head circumference in infants, and limb circumference
Require trained personnel and correct tools
Compare standards specific for age/gender
Assess trends in nutritional status/growth

28. Nutrition Deficiencies
Primary deficiency occurs when a person does not consume enough of a nutrient, a direct consequence of inadequate intake
Secondary deficiency occurs when:
A person cannot absorb enough of a nutrient in his or her body
Too much of a nutrient is excreted from the body
A nutrient is not utilized efficiently by the body

29. Deficiency Symptoms
Subclinical deficiency occurs in the early stages; few or no symptoms are observed
Covert symptoms are hidden and require laboratory tests or other invasive procedures to detect
Symptoms of nutrition deficiency that become obvious are overt

30. Scientific Method
To ensure that certain standards and processes are used in evaluating claims, the researcher:
Makes an observation and describes a phenomenon
Proposes a hypothesis (educated guess) to explain the phenomenon
Develops an experimental design to test the hypothesis
4. Collects and analyzes data to support or reject the hypothesis

31. Scientific Method
If the data are rejected, an alternative hypothesis is proposed and tested
If the data support the original hypothesis, a conclusion is drawn
The experiment must be repeatable, so other researchers can obtain similar results

32. Well-Designed Experiment
The sample size (number of people being studied) should be adequate enough to ensure that the results obtained are not due to chance alone
A control group is essential to comparison between treated and untreated individuals
Control for other variables to avoid coincidentally influencing the results

33. Advancing a Theory
A hypothesis that is supported by repeated experiments may be called a theory
A theory represents a scientific consensus (agreement) of why the phenomenon occurs
Theories can be challenged and changed as scientific knowledge evolves

34. Epidemiological Studies
Also known as observational studies:
Involve assessing nutritional habits, disease trends, or other health phenomena of large populations
Determine the factors that may influence these phenomena

35. Model Systems Human studies: Animal studies
Difficult to control for all of the variables
Humans have long life spans
Animal studies
Preliminary information for designing and implementing human studies
Research that cannot be done with humans
Drawbacks: results may not apply directly to humans; ethical implications of animal studies

36. Human Studies
Case control studies are epidemiological studies done on a smaller scale
Compare a group of individuals with a particular condition to a similar group without this condition
Clinical trials are controlled experiments
Experimental group receives the intervention
Control group is not given the intervention

37. Double-Blind, Placebo-Controlled Study
Most likely to produce valid, reliable data
Blinding
Neither researchers nor participants know which group is really getting the treatment
Helps prevent the researchers from seeing only the results they want to see
Placebo: imitation treatment that has no scientifically recognized therapeutic value
Psychosomatic effect or placebo effect

38. Evaluating Media Reports
Discerning truth or fallacy:
Who is reporting the information?
Who conducted the research; who paid for it?
Is the report based on reputable research studies?
Is the report based on testimonials?
Are the claims too good to be true?
Quackery: misrepresentation of a product, program, or service for financial gain

39. Trustworthy Nutrition Experts
Registered dietician (RD)
Licensed dietician meets the credentialing requirements of a given state
Nutritionist has no legal definition
Professional with advanced nutrition degree (master’s—MS, MA; doctoral—PhD)
Physician

40. Government Information Sources
Centers for Disease Control and Prevention (CDC)
National Health and Nutrition Examination Survey (NHANES)
Behavioral Risk Factor Surveillance System (BRFSS)
National Institutes of Health (NIH)

41. Reliable Nutrition Information
American Dietetic Association
American Society for Nutrition Sciences
Society for Nutrition Education
American College of Sports Medicine
North American Association for the Study of Obesity