Nutrition Assessment The science of determining nutrition status

1. Nutrition AssessmentThe science of determining nutrition status 1

2. Determine Your Nutritional Health The warning signs of poor nutritional health are often overlooked. Use this checklist to find out if you or someone you know is at nutritional risk. 2

3. I don't always have enough money to buy the food I need. 4 • I eat alone most of the time. 1 • I take 3 or more different prescribed or over-the-counter drugs a day. 1 • Without wanting to, I have lost or gained 10 pounds in the last 6 months. 2 • I am not always physically able to shop, cook and/or feed myself. 2 SCORES: 0–2 = good; 3–5 = moderate nutritional risk; 6 or more = high nutritional risk.

4. The Determine checklist, is based on these warning signs of poor nutrition: Disease Eating poorly Tooth loss, mouth pain Economic hardship Reduced social contact Multiple medicines Involuntary weight loss or gain Need for assistance in self-care Elderly (age > 80) The Nutrition Screening Initiative, a project of the American Academy of Family Physicians, the American Dietetic Association and the National Council on Aging, Inc., and funded in part by a grant from Ross Products Division, Abbott Laboratories.

5. Nutrition Assessment is a comprehensive approach completed by a registered dietitian for defining nutritional status using medical, social, nutritional and medication histories, physical examination, anthropometric measurements and laboratory data. The American Dietetic Association, Council on Practice, 1994

6. How To Assess Nutritional Status? Stages of deficiency Assessment method Inadequate food intake • Dietary evaluation Impaired absorption, utilization or transport Increased requirement, destruction or excretion • Biochemical & Anthropometry evaluation Decreased tissue levels • Biochemical evaluation Altered physiology/biochemical functions • Clinical evaluation Signs & Symptoms of deficiency

7. Methods of Nutrition Assessment A B C D nthropometric methods iochemical methods linical methods ietary methods Can be used alone, but more effectively in combination to provide an accurate picture of an individual’s nutrition status; Not based on a single determination but on a group or series of measurements & observations.

8. Nutritional Anthropometry Measure 1. variations of the physical dimensions (length, weight, proportions) 2. gross composition (fat mass, fat-free mass) of the human body at different age levels and degrees of nutrition. Jelliffe,1966

9. Nutritional Assessment Indices Constructed from 2 or more raw anthropometric measurements & are ratios. E.g. • Head circumference-for-age • Height-for-age • Weight-for-age • Weight-for-height • Weight changes A very widely used height -weight index is body mass index (BMI)

10. Weight (in kilogrammes) (Height)2(in metres) BMI = Body Mass Index • For adults >20 yrs (not for pregnant / lactating ) • high correlation with estimates of body fatness, a reliable indicator of obesity (adjusted by sex, race and age) • At the same BMI, female tend to have more body fat than male. • At the same BMI, older people, on average, tend to have more body fat than younger adults. • Does not distinguish excess fat from muscularity as the source of excessive body weight, so • Highly trained athletes may have a high BMI because of ↑ muscularity rather than ↑ body fatness. • For children 2-20 years, use BMI for age

11. Body Mass Index

12. Evaluating Indices & Data Of Nutritional Assessment Classification: “at risk” or “not at risk” • E.g. disease risk for type 2 diabetes, hypertension & CVD • Waist Circumference (NIH): high risk in adult males > 102 cm • adult females > 88 cm (NIH) • Systems available • Reference limits from appropriate reference data: “at risk” of malnutrition • 2 SD above & below median reference data • below 3rd / 5th percentiles or above 97th / 95th percentiles (e.g. growth charts) • 2. Cut-off points • E.g. WHO cutoff points for anemia (Hb < 120 g/L)

13. Advantages Procedure Simple, safe, non-invasive Applicable to large sample size Equipment – portable, inexpensive Unskilled personnel/minimal training Evaluate changes in nutritional status over time Limitations Insensitive – cannot detect disturbance over short periods of time Unable to distinguish between specific nutrient deficiencies Lack of appropriate standards to compare results Anthropometry

14. Biochemical Assessment • Lab measurements done on available body tissues, usually blood or urine Measures • Nutrients • Nutrients metabolites • Substances that contain the nutrient (e.g. Hb for iron) • Enzymes that require the nutrient (e.g. transketolase for thiamin) • Substances that result from abnormal metabolism from a deficiency of the nutrient (e.g. elevated pyruvate levels in thiamin deficiency)

15. Biochemical Assessment • Provide the most objective and quantitative data on nutritional status • Can detect sub-clinical deficiency = uncovers early signs of malnutrition before alterations in anthropometric measures or clinical signs/symptoms of a deficiency disease appear • Sufficiently accurate to use as a validation method in dietary surveys • May be influenced by non-nutrition factors like disease or medication use

16. Clinical Assessment

17. Clinical Assessment • Consists of a routine medical history + nutrition-focused physical examination to detect signs and symptoms associated with malnutrition • Most useful during advanced stages of nutritional depletion, usually when overt signs already present • Many physical signs are non-specific  need to interpret together with laboratory, anthropometric and dietary data to identify the specific nutritional deficiency

18. Limitations Of Physical Examination • Non specificity of the physical signs some may be produced by >1 nutrient deficiency or by non-nutritional factors • Multiple physical signs may exhibit multiple physical signs due to co-existing nutrient deficiencies  confusion • Signs may be two-directional occur during the development of a deficiency and/or recovery • Examiner inconsistencies bias

19. Dietary Assessment • To determine an individual or population’s usual dietary intake • To identify potential dietary inadequacies • To provide data on intake of nutrients or specific classes of food • Involves surveys: measures quantity of individual foods consumed in one to several days assesses the pattern of food used during the previous several months

20. Measuring Food Consumption • Assessment methods provide qualitative or quantitative information from food consumption surveys • Data collected at: • National level • Household level • Individual level

21. Methods Of Dietary Assessment Of Individuals • 24-hour recall method • Estimated food records • Weighed food records • Diet history • Food Frequency Questionnaire

22. 24-hour Recall Method • Subjects (their parents or caregivers) are asked to recall exact food intake during the previous 24 hour period • Detailed description of all foods & beverages consumed, including cooking methods and brand names (if possible) are recorded • Quantities of foods consumed are usually estimated in household measures • Photographs, food models & utensils of various types can be used as memory aids and/or to assist in assessing portion size • The interviewer records the information for later coding and analysis

23. 24-hour Recall Method • Conducted in 4 stages using a standardised protocol • 1) recall of foods and drinks consumed • 2) description of foods and drinks consumed • 3) estimation of amounts – food models • 4) review of interview data

24. Success depends on: • subject’s memory • ability of the respondent to convey accurate estimates of portion size consumed • degree of motivation of the respondent • persistence of the interviewer

25. low respondent burden, high compliance low cost ease and speed of use its administration does not alter the usual diet can provide detailed information on types of food consumed ideal for illiterate respondents can be used to estimate nutrient intake of groups reliance on memory  difficult for the elderly and young children estimation errors of food portion sizes occur (can be reduced by using graduated food models) one recall is seldom representative of a person’s usual intake over-report low intakes & under-report high intakes withold/alter information because of embarrassment data entry can be labour intensive Advantages Limitations

26. Food Record / Diary • The respondent records, at the time of consumption, the identity and amounts of all foods and liquids consumed • Period of time usually 3 - 7 days • Includes information on time, place and situation of eating

27. Estimatedfood records • Record - time of consumption for each food • Detail description - brand names, method of preparation • Composite dish - raw ingredients, final weight of dish • Portion size – in household measurement • Convert to gram for analysis

28. Most precise – requires weighing scale • Weigh all foods and beverages consumed by the subject • Details - preparation, brand names • Method is same as estimated food records except the weighing Weighed food records

29. Limitations Advantages • Requires lots of co-operation • Respondent burden  low response rates • Subject must be literate • Time-consuming • Analysis is labor-intensive & expensive • Act of recording may alter diet • Does not depend on memory • Provides detailed intake data • Provides data about eating habits • Multiple-day data is more representative of usual intake

30. Diet History • A detailed dietary assessment • Assess individual’s usual dietary intake over extended period of time (past month or year) • Burke’s original method involved 4 steps: • General info about health habits – smoking, exercise, appetite, use of supplements, food dislikes, intolerances, weight history etc • 24 hr recall - actual intake and general information on the overall eating pattern • Cross check on data with specific questions about preferences/habits e.g. diet changes • 3-day food record (additional means to check the usual intake, many omit this step)

31. Advantages Limitations • Lengthy interview • Requires trained interviewers • Difficult & expensive to analyse • May over-estimate nutrient intake • Requires respondent’s co-operation • Assesses usual nutrient intake • Can detect seasonal changes • Data on all nutrients obtained • Correlates well with biochemical measures

32. Food Frequency Questionnaire Assesses energy/nutrient intake by determining how frequently a person consumes a limited number of foods that are major sources of the nutrient in question Questionnaire consist of a list of individual food/good groups that are important contributors to the population’s intake of energy and nutrients Respondents indicate how many times a day/week/month/year they consume the foods

33. Simple/non-quantitative format • Choice of portion sizes not given, generally use ‘standard’ portion sizes – the amount customarily eaten per serving for various age/sex groups • E.g. how many times one eats dark bread or ice cream Semi-quantitative format • Gives respondent an idea of portion sizes • E.g. how many times one eats a slice of dark bread or ½ cup serving of ice cream Quantitative format • The respondent needs to describe the size of his/her usual serving as small, medium or large relative to a standard serving • The information is then entered into a database which multiples the nutrients content and arrives at an estimated nutrient intake

34. FFQs known as screeners have been developed to assess intake of calcium, dietary fiber, fruits and vegetable, and percent energy from fat. Useful in situations that do not require assessment of the total diet or quantitative accuracy in dietary estimates or when financial resources are limited Commonly used in epidemiologic research investigating the relationship between diet and such conditions as cancer or CVD Can be self-administered and machine readable – cost effective for measuring diet in large epidemiologic studies

35. can be self-administered machine readable modest demand on respondents inexpensive for large sample sizes more representative of usual intake than a few days of diet records design can be based on large population data Considered by some to be the method of choice for research on diet-disease relationships may not represent usual foods or portion sizes chosen by respondents intake data can be compromised when multiple foods are grouped with single listings depends on ability of subject to describe diet Limitations Advantages

36. Food Consumption Data • To calculate nutrient intakes of individuals or population groups if quantitative methods were used to collect data • Calculation of nutrient intakes: • Manual calculations using food composition tables • Computer calculation using nutrient databases stored in computer • Nutrient data banks or computer-stored nutrient databases are from food composition tables transferred to and maintained on a computer

37. Food Composition Tables • Printed tables contain lists of thousands of foods with the quantities of each nutrient (values) in a standard amount (e.g. 100g) for each food • Nutrient values are based on a quantitative analysis of samples of each food • Data is representative of the average composition of a particular foodstuff on a year-round, nationwide basis • Values expressed in terms of the nutrient content of the edible portion of the food per 100g and /or per common household measures

38. Uses Of Food Composition Tables • To compare the nutritive value of one food with another • To calculate nutritive value of any diet so as to compare that diet with the RDA • To plan diets that must meet specific requirements e.g. 250mg sodium or 100g protein, etc • To provide a ready reference to answer questions that people ask about foods. Proper use of the tables can counteract much nutritional misinformation

39. Limitations Of Food Composition Tables • Errors in data - random e.g. due to natural variability in the composition of the foods / processing techniques -systematic e.g. sampling procedures or method of analysis of the foods • Limited range of foods covered • Recipe variations • Effect of storage on nutrient content • Incorrect/ambiguous description of individual food item e.g. prawn paste, flat bread • Inconsistencies in terminology used to express certain nutrients

40. Nutrient Analysis a) Manual calculations • select appropriate food composition table • record each type of food listed during the recall • calculate the edible portion : grams or household measures • convert into decimal fraction • multiply the nutrient values from food composition table • total

41. b) Computer calculations • Completeness depends on range of listed food & availability of nutrient values • Steps • select appropriate database / nutrient • calculate edible portion consumed • enter data • check input data for transcription errors • total, averages & comparisons to RDAs can be displayed

42. Reference values that are quantitative estimates of nutrient intakes to be used for planning and assessing diets for apparently healthy people The Dietary Reference Intakes (DRIs)

43. The Dietary Reference Intakes (DRIs) Include 4 reference intakes • EAR • NRI • AI = adequate intake, an observational standard that is used when insufficient data is available to determine RDA • UL = tolerable upper intake level, highest level of daily nutrient intake that is likely to pose no risk of adverse healthy effects to almost all apparently healthy individuals in the general population

44. EAR UL RNI Safe range of intake

46. Indices of Diet Quality Nutrient density • Refers to a food’s vitamin & mineral content relative to its energy contenti.e. a nutrient dense food is one that is a good source of vitamins & minerals but relatively low in energy • Expressed as the amount of a nutrient per 1000kcal • E.g. the deep fried broccoli will have many of the same vitamins & minerals as the steamed one but the sauces & oil will add extra calories • Nutrient density allows easy & quick evaluation of quality of foods & diets independently of serving size

47. Nutrient Adequacy Ratio (NAR) • represents an index of adequacy for a nutrient based on the corresponding RDA for that nutrient • NAR = subject’s daily intake of a nutrient age-specific RDA of that nutrient Example: Sally, a 15 year old teenager, has an average daily intake of 12 mg iron. The RNI for iron for teenage girls (14-16 years) is 18 mg/day. NAR = 12/18 = 0.67 Mean adequacy ratio = sum of NARs for all evaluated nutrients divided by the number of nutrients evaluated.A composite indicator for micronutrient adequacy, allows evaluation of overall adequacy of selected nutrients in thediet. Nutrient intake considered adequate if NAR > 0.67

48. Average intake for nutrient X +2 SD -2 SD Standard deviation or Z score • a measure of an individual’s nutrient intake in relation to the distribution of nutrient intakes of the group • does not evaluate nutrient intakes in relation to the recommended nutrient intakes • useful in longitudinal studies Intake values for nutrient X

49. Index of Nutritional Quality (INQ) • INQ = nutrient per 100 g food / RDA for the nutrient energy per 100 g food / energy requirement • Example: Is egg or cheddar cheese a better source of protein? Data: 100 g cheddar cheese has 25 g protein, 403 kcal 100 g eggs has 12.4 g protein, 141 kcal For ♂ 18-30 years, NRI for protein = 65g, energy = 2100 kcal/day) INQ (egg) = 12.4/65 INQ (c cheese) = 25/65 141/2100 403/2100 = 2.84 = 2.00

50. INQ = 1 indicates that the food is an adequate source of the nutrient INQ = 2-6 indicates that the food is a good source of the nutrient INQ > 6 indicates that the food is an excellent source of the nutrient →Both are good sources of protein, with eggs first, second cheddar cheese • Excellent rating for a single nutrient does not reflect equivalent rating for other nutrient