An Overview of Nutrition

1. An Overview of Nutrition Chapter 1

2. Chapter 1 Objectives • Describe how various factors influence personal food choices. • Name the six classes of nutrients • Identify which are organic. • Identify a major use of each nutrient. • Identify which provide energy and calculate the energy available from foods. • Explain the scientific method. • Explain the role of nutritional genomics in the science of nutrition. • List the strengths and weaknesses of research designs. • Define the four categories of the DRI (EAR, RDA, AI, UL) and explain their purposes. • Explain how the EER is used to maintain energy balance. • Discuss the AMDR and how they relate to a healthy diet. • Use the DRI to assess a healthy individual. • Explain how the four assessment methods are used to detect energy and nutrient deficiencies and excesses. • List the four parts of a nutritional assessment and apply them to individuals to detect malnutrition. • List the major methods used to survey the nutritional status of populations. • Identify several risk factors and explain their relationships to chronic diseases. • Recognize misinformation and describe how to identify reliable nutrition information. • Identify accurate sources of nutrition information. • List the 8 red flags that identify nutrition misinformation.

3. Introduction • Daily food choices • Benefit health • Harm health • Chronic disease • Diet = what we eat • Foods and beverages

4. Food Choices • Choices are highly personal • Complex interaction of genetic, social and behavioral motives • Personal preference = #1 • Taste: sugar, salt, fat • Genetics, hormones • Ethnic or regional heritage and tradition • Habit

5. Food Choices • Social interactions • Availability, convenience, and economy • Benefits of home-cooked meals • Positive and negative associations • Emotions • Boredom, depression, anxiety, stress

6. Food Choices • Values • Religious beliefs, political views, environmental concerns • Body weight and image • Nutrition and health benefits • Functional foods = foods that provide health benefits beyond their nutrient contributions • Examples: tomato (lycopene), orange juice (calcium), margarine (sterols)

7. The Nutrients • Water • Inorganic • No energy • Minerals • Simplest nutrient • Inorganic • No energy • Vitamins • Organic • No Energy • Carbohydrates • Organic • Energy • Proteins • Organic • Contains nitrogen • Energy • Lipids/Fats • Organic • Energy

8. Elements in the Six Classes of Nutrients

9. Energy-Yielding Nutrients • Amount of energy in food • Depends on composition • Using nutrients for energy • Breaking of bonds • Storage of excess energy • Metabolism • Materials for building body tissues • Regulation of bodily activities

10. Energy-Yielding Nutrients • Provide kcalories • Carbohydrate = 4 kcal/g • Protein = 4 kcal/g • Fat = 9 kcal/g • Alcohol • Not a nutrient • Yields energy = 7 kcal/g • Macronutrients vs. micronutrients

11. The Vitamins • Thirteen organic vitamins • Water-soluble vitamins • Fat-soluble vitamins • Facilitate energy release • Almost every bodily action requires assistance from vitamins • Vulnerable to destruction • Heat (vit C), light (riboflavin)

12. The Minerals & Water • Minerals • Do not yield energy • Sixteen essential minerals • Indestructible • Causes of mineral losses from foods • Bound and unable to be absorbed (phytates), leach into water (sodium) • Water • Medium for nearly all body activities

14. The Science of Nutrition • Foundation in several other sciences • Biology, biochemistry, physiology • Tremendous growth • Sequencing of human genome • Nutritional genomics: nutrient-gene-disease

15. Conducting Research • Use of scientific method • Systematic process for conducting research • Research studies • Controls • Randomization • Sample size • Placebos • Double-blind experiments

16. OBSERVATION & QUESTION Identify a problem to be solved or ask a specific question to be answered. HYPOTHESIS & PREDICTION Formulate a hypothesis—a tentative solution to the problem or answer to the question—and make a prediction that can be tested. EXPERIMENT Design a study and conduct the research to collect relevant data. RESULTS & INTERPRETATIONS Summarize, analyze, and interpret the data; draw conclusions. HYPOTHESIS SUPPORTED HYPOTHESIS NOT SUPPORTED THEORY NEW OBSERVATIONS & QUESTIONS Develop a theory that integrates conclusions with those from numerous other studies. Stepped Art Figure 1-3 p13

17. Conducting Research • Epidemiological studies: incidence, distribution, control of disease in pop. • Cross-sectional studies • Case-control studies • Cohort studies • Experimental studies: cause-and-effect relationships • Laboratory-based animal studies • Laboratory-base in vitro studies • Clinical trials

18. Examples of Research Designs Fig. 1-4 (pg 14)

19. Examples of Research Designs Fig. 1-4 (pg 14)

20. Analyzing Research Findings • Correlations – only show association • Positive correlation • Not necessarily a desired outcome • Negative correlation • No correlation • Cautious interpretations and conclusions • Accumulation of evidence

21. Publishing Research • Peer review • Research has validity • Findings are preliminary when published • Not meaningful by themselves • Findings need to be replicated

22. Parts of a Research Article

24. Dietary Reference Intakes • Standards defined for: • Energy • Nutrients • Physical activity • Collaborative effort of U.S. and Canada • Recommendations apply to healthy people • May be different for specific groups

25. Dietary Reference Intakes • Estimated Average Requirements (EAR) • Average amount sufficient for half of population • Recommended Dietary Allowances (RDA) • Recommendations to meet needs of most healthy people • About 98% of population

26. EAR and RDA Compared

27. Dietary Reference Intakes • Adequate Intakes (AI) • Insufficient scientific evidence • AI value set instead of RDA • Expected to exceed average requirements • Tolerable Upper Intake Levels (UL) • Point where nutrient is likely to be toxic • Helps protect against overconsumption

28. Inaccurate vs. Accurate View of Nutrient Intakes

29. Dietary Reference Intakes • Estimated Energy Requirement (EER) • Average dietary energy intake to maintain energy balance • Healthy body weight • Physical activity • No upper level

30. Dietary Reference Intakes • Acceptable Macronutrient Distribution Ranges (AMDR) • Adequate energy and nutrients • Reduce risk of chronic diseases • Range • 45-65% kcalories from carbohydrate • 20-35% kcalories from fat • 10-35% kcalories from protein

31. Dietary Reference Intakes • Estimates apply to healthy people • Needed adjustments • Recommendations – not minimum levels nor optimal levels • Goals intended to be met through diet • Apply to average daily intakes • Each DRI category serves a unique purpose

33. Nutrition Assessment – Individual Level • Deficiency or excess over time leads to malnutrition • Undernutrition and overnutrition • Symptoms of malnutrition • Diarrhea • Skin rashes • Fatigue • Others

34. Nutrition Assessment – Individual Level • Creating a “total picture” of the individual • Historical information • Health status, SES, drug use • Diet history – intake over several days; portion sizes; computer analysis • Anthropometric measurements • Height and weight – track to identify trends • Physical examinations • Laboratory tests

35. Stages in the Development of a Nutrient Deficiency

36. Nutrition Assessment – Population Level • National nutrition surveys • National nutrition monitoring program • Coordinates two major national surveys • Oversample high-risk groups • National health goals • Healthy People • National trends

37. Healthy People 2020 Nutrition & Weight Status Objectives

38. Healthy People 2020 Nutrition & Weight Status Objectives

39. Diet and Health • Food plays vital role in supporting health • Chronic disease – epidemic levels • Multiple factors over multiple years • Leading causes of death

40. Diet and Health • Risk factors • Persist over time • Cluster • Prominence of risk factors • Tobacco • Diet & activity patterns • Others

42. Nutrition Information & Misinformation Highlight 1

43. Nutrition Information & Misinformation • Validity of information • Who is providing information? • Qualifications • Internet • Anyone can publish anything • No guarantees of accuracy • Evaluate websites • Who, When, Where, Why, and What?

44. Nutrition Information & Misinformation • News • Often tell lopsided story • Testimonials • Tight deadlines • Limited understanding • Current and controversial

45. Nutrition Information & Misinformation • Identifying nutrition experts • Physicians & other health-care professionals • Training in nutrition is limited • Registered Dietitian (RD) • Degree and clinical internship • National exam • Maintain up-to-date knowledge • Dietetic Technician Registered (DTR)

46. Nutrition Information & Misinformation • Identifying fake credentials • Accreditation • Diploma mills • Fraudulent businesses • Red flags of nutrition quackery • Misinformation

47. Nutrition Information & Misinformation