1. NS 210 – Unit 3 Seminar Measuring Diets and Interview Techniques Jennifer Neily, MS, RD, CSSD, LD Registered/Licensed Dietitian Kaplan University

2. Reasons for Measuring Diet “TO IMPROVE HUMAN HEALTH” 4 Major Uses Of Dietary Intake Data –Assessing and monitoring intake –Formulating and evaluating government and agricultural policy –Epidemiologic research –Commercial purposes

3. Assessing and Monitoring Food and Nutrient Intake Ensuring adequacy of the food supply Estimating the adequacy of dietary intakes of individuals and groups Monitoring trends in food and nutrient consumption Estimating exposure to food additives and contaminants

4. Figure 1 Source: Journal of the American Dietetic Association 2010; 110:1638-1645 (DOI:10.1016/j.jada.2010.08.018 )Journal of the American Dietetic Association 2010; 110:1638-1645 Copyright © 2010 American Dietetic

5. Figure 3 Source: Journal of the American Dietetic Association 2010; 110:1638-1645 (DOI:10.1016/j.jada.2010.08.018 )Journal of the American Dietetic Association 2010; 110:1638-1645

6. Formulating and Evaluating Government Health & Agricultural Policy Planning food production and distribution Establishing food production and distribution Establishing programs for nutrition education and disease risk reduction Evaluating the success and cost-effectiveness of nutrition education and disease risk reduction programs

7. Conducting Epidemiologic Research Studying the relationships between diet and health Identifying groups at risk of developing diseases because of their diet and/or nutrient intake

8. Commercial Purposes Data from national nutrition surveys are used by the food manufacturers to develop advertising campaigns or new food products

9. Measuring Diet Most widely used indirect indicator of nutritional status Estimating intake can be difficult –Weakness of data-gathering techniques –Human behavior –Natural tendency of intake –Limitations of nutrient composition tables and databases

10. Methods for Measuring Intake 24-hour recall Food Record or Diary Food Frequency Questionnaires (FFQs) Diet History Duplicate Food Collections Food Accounts Food Balance Sheets Photographic and Digital Video Methods

11. 24-Hour Recall Strengths –Requires less than 20 minutes –Inexpensive –Easy to administer –Low respondent burden –Can provide detail info on types of food consumed –Probability sampling possible –More objective than dietary history –Does not alter usual diet Limitations –One recall is seldom representative of a person’s usually intake –Underreporting/ overrreporting occurs –Relies on memory –Omissions of dressings, sauces, and beverages can lead to low estimates of energy intake –May be a tendency to overreport intake at low levels and overreport intake at high levels of consumption –Data entry can be very labor intensive

12. Food Record or Food Diary An extensive record of log including brands and portions of all foods eaten over the course of several days or weeks. A diary may include more information like when, where, and with whom.

14. One month “Billy C” client food record

15. Food Record or Diary Strengths –Does not depend on memory –Can provide detailed intake data –Can provide data about eating habits –Multiple-day data more representative of usually intake –Reasonably valid up to 5 days Limitations –Requires high degree of cooperation –Response burden can result in low response rates when used in large national surveys –Subject must be literate –Takes more time to obtain data –Act of recording may alter diet –Analysis is labor intensive and expensive. –Must know portions and be able to estimate

17. Food Frequency Questionnaires (FFQ) Assess energy and/or nutrient intake by determining frequency of intake Usually 150 foods or less. What food and how often May take 7 – 60 minutes depending on complexity of FFQ May provide visual pictures/graphics to help assess portion

18. Food Frequency Questionniares Strengths –Usually self administered –Computer read –Modest demand on respondents –Relatively inexpensive for large sample sizes –May be more representative of usual intake than food diary –Design can be based on large population data –Considered by some as the method of choice for research on diet-disease relationships Limitations –May not represent usual foods or portion sizes chosen –Intake data can be compromised when multiple foods are grouped within single listings –Depend on ability of subject to describe diet

20. Block Questionnaires Very popular in research setting Solid history of validatoin Evidence based results used in hundreds of research studies. Multiple versions: long, short, fruits/veggies, meat, soy, nutrients, adults, children, physical activity

21. Diet History Strengths –Assesses usually nutrient intake –Can detect seasonal changes –Data on all nutrients can be obtained –Can correlate well with biochemical means Limitations –Lengthy interview process –Requires highly trained interviewers –Difficult and expensive to code –May tend to overestimate nutrient intake –Requires cooperative respondent with ability to recall usual diet

22. Food Accounts Strengths –Suitable for use with large sample size –Can be used over relatively long periods –Gives data on dietary patterns and habits of families and other groups –Less likely to lead to alterations in diet than some other methods –Relatively economical Limitations –Does not account for food losses –Respondent literacy and cooperation necessary –Not appropriate for measuring individual food consumption

23. Food Balance Sheet Strengths –Can give a total view of a country’s food supplies –Indicates food habits and dietary trends –Sued to plan international nutrition policies and food programs –May be the only data available on a country’s food consumption practices Limitations –Accuracy of data may be questionable –Only represents food available for consumption –Does not represent food actually consumed –Does not indicate how food was distributed –Does not account for wasted food

24. Other Interview Techniques Duplicate Food Collection Method Photographic and Video Records Computerized Techniques

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26. Issues in Dietary Measurement Validity –Ability of an instrument to measure what it is intended to measure Reproducibility –The ability of a method to produce the same estimate on two or more occasions How Many Days? –It is important to know how long a dietary intake must be measure before a sufficiently reliable estimate of usual intake is obtained

27. Estimating Portion Sizes Photographs of food Geometric Shapes Measuring Devices Lifelike plastic food models

28. Estimating Portion Sizes… Portion Distortion!

29. FRENCH FRIES 20 Years Ago Today 210 Calories 2.4 ounces How many calories are in today’s portion of fries? National Heart Lung and Blood Institute

30. FRENCH FRIES 20 Years Ago Today 210 Calories 2.4 ounces National Heart Lung and Blood Institute 610 Calories 6.9 ounces

31. How long will you have to walk leisurely in order to burn those extra 400 calories?* *Based on 160-pound person Maintaining a Healthy Weight is a Balancing Act Calories In = Calories Out National Heart Lung and Blood Institute

32. *Based on 160-pound person If you walk leisurely for 1 hour and 10 minutes you will burn approximately 400 calories.* Calories In = Calories Out National Heart Lung and Blood Institute

33. 320 calories How many calories are in today’s turkey sandwich? TURKEY SANDWICH 20 Years Ago Today National Heart Lung and Blood Institute

34. 320 calories TURKEY SANDWICH 20 Years Ago Today National Heart Lung and Blood Institute 820 calories

35. *Based on 160-pound person If you ride a bike for 1 hour and 25 minutes, you will burn approximately 500 calories.* Calories In = Calories Out National Heart Lung and Blood Institute

36. CHICKEN CAESAR SALAD 20 Years Ago Today 390 calories 1 ½ cups How many calories are in today’s chicken Caesar salad? National Heart Lung and Blood Institute

37. CHICKEN CAESAR SALAD 20 Years Ago Today 390 calories 1 ½ cups National Heart Lung and Blood Institute 790 calories 3 ½ cups Calorie Difference: 400 calories

38. Bagel Calorie difference: 210 25 years ago: – 140 calories – 2 inch diameter Today: – 350 - 400 calories – 6 inch diameter

39. Blueberry Muffin Calorie difference: 290 25 years ago: – 210 calories – 1.5 ounces Today: – 500 calories – 4 ounces

40. Chocolate Chip Cookie Calorie difference: 220+++ 25 years ago: – 55 calories – 1.5 inch diameter Today: – 275 - 600 calories – 3.5 - 4 inch diameter

41. Overview of Chapter 3 Research Design Considerations –Correlation Studies –Case Control Studies –Cohort studies Factors that influence selection of dietary methods Different Techniques in Measuring diet –Strengths and Limitations Validating Dietary Methods

42. Stuff you need to know! Always check announcements and your email. Unit 5 midterm coming up. Information posted in Doc Sharing. It’s worth 140 points – 14% of your grade! New sections in Doc Sharing: –APA info, samples and formatting –Turnitin.com and plagiarism