An Overview of Nutrition

1. An Overview of Nutrition Chapter 1

2. Food Choices • Choices are highly personal • Social or behavioral motives • Personal preference • Taste • Sweet and salty • Genetics • Habit • Ethnic heritage or tradition

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

4. Food Choices • Values • Religious beliefs, political views, environmental concerns • Body weight and image • Nutrition and health benefits • Functional foods • Examples

5. The Nutrients • Water • Hydrogen & oxygen • Inorganic • Minerals • Simplest nutrient • Inorganic • Vitamins • Organic • Carbohydrates • Organic • Proteins • Organic • Contains nitrogen • Lipids (fats) • Organic

6. The Nutrients

7. Nutrient Composition of the Body

8. 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

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

10. 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 • Examples

11. The Minerals & Water • Minerals • Do not yield energy • Sixteen essential minerals • Indestructible • Causes of mineral losses from foods • Water • Medium for nearly all body activities

12. The Science of Nutrition • Foundation in several other sciences • Biology, biochemistry, physiology • Tremendous growth • Sequencing of human genome • Nutritional genomics

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

14. The Scientific Method

15. 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 Fig. 1-3, p. 12

16. Conducting Research • Epidemiological studies • Cross-sectional studies • Case-control studies • Cohort studies • Experimental studies • Laboratory-based animal studies • Laboratory-base in vitro studies • Clinical trials

17. Conducting Research

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

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

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

21. 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

22. Dietary Reference Intakes

23. 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

24. Dietary Reference Intakes

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

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

27. 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

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

29. 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

30. Nutrition Assessment – Individual Level

31. Nutrition Assessment – Individual Level

32. 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

33. Diet and Health • Food plays vital role in supporting health • Chronic disease – epidemic levels • Multiple factors over multiple years • Leading causes of death • Risk factors • Presence or absence in relation to disease • Tend to persist over time • Tend to cluster

34. Diet and Health

35. Highlight 1 Nutrition Information and Misinformation

36. 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?

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

38. 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)

39. Nutrition Information & Misinformation