DIETARY ASSESSMENT By Lalita Bhattacharjee Nutritionist Training on Assessment of Nutritional Status 18-22 December 2011 Date : 21 December 2011 Venue: FPMU Meeting Room The Training is organized by the National National Food Policy Capacity Strengthening Programme (NFPCSP) . The NFPCSP is jointly implemented by the Food Planning and Monitoring Unit (FPMU), Ministry of Food and DisasterManagement and Food and Agriculture Organization of the United Nations (FAO) with the financial support of the EU and USAID.
Whoever was the father of adisease, an ill diet was the mother!
OUTLINE Introduction Determinants of food intake and nutritional status National and household food consumption surveys Assessment of individual food and nutrient intakes and nutrient adequacy Food frequency questionnaires, Rapid methods of dietary assessment Validation and Reliability Recommended dietary intake and evaluating nutrient intakes Conclusion
OPTIMAL NUTRITIONALSTATUS Source: Mahan and Stump, 2000
DIETARY ASSESSMENT ANDNUTRITIONAL ASSESSMENT : KEY TERMS A DIETARY ASSESMENT : comprehensive evaluation of a persons food intake. It is one of the established methods of nutritional assessment. Dietary assessment techniques range from food records to questionnaires and biological markers. NUTRITIONAL ASSESSMENT : more comprehensive and includes determining nutritional status by analyzing the individual’s brief socio economic background, medical history, dietary, anthropometric, biochemical, clinical data and drug – nutrient interactions NUTRITIONAL STATUS : measurement of the extent to which an individual’s physiologic need for nutrients is being met NUTRIENT INTAKE : depends on actual food consumption which is influenced by factors such as economic situation, eating behaviour, emotional climate, cultural influences, effects of disease states on appetite and the ability to absorb nutrients NUTRIENT REQUIREMENTS : are determined and influenced by age, sex, BMR, physiological status, activity patterns, physiologic
Dimensions and methods forassessing food security and undernutrition Methods Availability Access to Consumption Utilization of food food of food of nutrients FAO Method Household income& expenditure surveysIndividual food consumption/intake surveysAnthropometry Qualitative measures of food security
Development of clinical deficiency withcorresponding dietary, biochemical and clinical evaluation
Methods of assessing dietaryintake National food supply data Household data Individual data (Food records, 24 hr dietary recall, FFQs, diet histories, food habit questionnaires, combined methods RAP - rapid assessment procedure ( focus groups to gather information on food behaviours, beliefs and intakes)
National and household food consumption Food consumption data collected at national, HH or individual levels Individual intake data required for assessing nutrient adequacy Food supply and HH data can provide useful information Food consumption assessment at national level based on FBS ( per capita availability, no individual variation in food intake) Food supply data useful
(En%) of cereals and rice to Bangladesh dietSource/Year Energy Cereal (g) Rice (g) intake (kcal) En % En % 452 440HIES 2005 2238 70% 68% 442 416HIES 2010 2318 66% 64%
DIETARY ASSESSMENT PRINCIPLESAdequacy : a diet that provides enough energy and nutrients to meet the needs according to the recommended dietary intakes/allowances (for healthy and active life)Balance : a diet that provides enough, but not too much of eachtype of food ( adequacy of basic food groups)Variety : a diet that includes a wide selection of foods within eachfood group (dietary diversity/ includes biodiversity – species, varieties, cultivars)Nutrient Density : a diet that includes foods that provide the most nutrients for the least number of calories (nutrient dense foods)Moderation : A diet that limits intake of foods high in sugar and fat (nutrient intake goals/guidelines)
Methods of obtaining dietaryintake dataMethod Advantages DisadvantagesNutrient intake analysis Allows actual observation May yield inconsistent and of food intake subjective estimates of food consumption; possible variation in portion sizeDaily food record or diary Provides daily record of Variable literacy skills of food consumption; can participants; requires provide information on ability to measure or judge quantity of food; how food portion sizes; actual food is prepared; and timing of intake possibly influenced meals and snacks by the recording process; questionable reliability of recordsFood frequency Easily standardized; can Requires literacy skills; be beneficial when does not provide meal considered in combination pattern data; requires with usual intake; provides knowledge of portion sizes overall picture of intake24 Hour Recall Quick, easy Relies on memory
Assessment of individual intakes Dietary records Record all foods and beverages consumed over a specific time period (3-4 d) Amount consumed determined by weighing with a scale or measuring volume using standard cups and spoons Specific/special foods may be recorded (fat, vitamin A, iron rich) Total energy intake will require all foods to be recorded.
Food Diary : DAYMeal Foods ( list Amount How Where eaten ) eaten prepared (home, work, etc)BreakfastSnackLunchTeaDinnerFood supplements : Name…… (cans/d)Vitamins/minerals supplement :….
Assessment of individual intakesDiet history• Collection of information on frequency of intake of various foods and usual meal pattern• Entails detailed listing of foods and beverages consumed at each eating session• 3 d - diet record as an independent check on food intake• Methods of preparation
Assessment of individual intakes : 24 dieta Get an accurate and complete listing of all food/drink individual consumed within last 24 hrs Specifically: What food/drink was consumed? How much was consumed? Time it was consumed? How was it prepared? How was it served? Details of food (e.g low fat, 1%, whole, milk powder, preparation, )
Assessment of individual intakes24 hour recall : Recall all the foods and beverages consumed the previous day or 24 hours prior to the interview Interviewers should be knowledgeable about foods available in the market Regional and ethnic preparations and methods Interview conducted face –to-face, structured w/o probing questions Estimates of portion size are made using standardized cups and spoons Record of food amounts converted into nutrient intakes using food composition tables
Assessment of individualintakesFood frequency questionnaire (FFQ) Report usual frequency of consumption of each food item from a list of food items in reference to a specified period (past wk/mo/yr) Face to face interview, telephone or by self administration Describes dietary patterns or food habits not nutrient intake Semi quantified tools can obtain information on portion size using household measures
FFQ - Examples : For each item indicate with a check mark the category that best describes the frequency with which you usually eat that particular food; complete questionnaire might contain more than 100 items Food item > 1/d 1/d 3-6 1-2/wk 2/mth or Never times/wk lessBeefFishLiverPoultryEggsDried beansGreen leafyvegetablesEnter other foods not listed thatare eaten regularly1.-------------2. -------------3. -----------
Example of semi quantitative FFQFood Medium Serving How often ? serving S M L D W M Y NApples, apple 1 or ½sauce cupBanana 1 mediumPapaya ¼ mediumWater melon 1 sliceOrange 1 mediumBel juice 6 oz glassCoconut water 4 oz glass
Relative risk of lung cancer according to categories of baseline carotenoid and fruit + vegetable intake Quintile of nutrient or Median Relative risk intake/d (n)Carotenoids (mcg)1 ( < 2770) ( 397) 2170 1.002 ( 2770-3786) (364) 3281 0.943 (3787 – 4988) (320) 4344 0.804 (4989 – 6792) (276) 5777 0.705 ( > 6792) (287) 8577 0.72 P for trend < 0.0001Fruits + vegetables (g)1 ( < 116 ) 407 80 1.002 ( 116-176) 362 147 0.883 ( 177 – 241 ) 326 207 0.794 ( 242 – 332) 293 280 0.715 ( > 332) ( 256) 415 0.64 Amer J Epidemiol (2002) 156: 536 -547
Estimating average intake of nutrients Specification of portion size – standardized portions (Willet ) Description of portion size – small, medium, large (Block) Information on frequency and serving size allows for estimating nutrient intakes Food list should contain foods that contribute to majority of the nutrients/specific in the diet (represent 75% of the nutrient intake –selected nutrients) % adequacy of food groups % adequacy of RDA for energy and nutrients including micronutrients Used in epidemiological research to study diet disease relationships
Rapid methods for community dietary assessment Dietary assessment of development of culture - HHs with children under 5s specific relevant food usage list Rapid assessment survey (focus group interviews, Linking food intake data with weighing /measuring of selected target group children & mother interviews IYCF practices, Derive mother’s BMI from Social customs and food standard tables beliefs, behaviours & intakes Key informants – community leaders, local shop owners or health personnel Small clusters of women 5-6 women sufficient for FGD
Strengths and limitations of dietary assessmentmethodsMethod Strengths LimitationsFood record Does not rely on memory; open ended High participation burden; requires literacy; may alter intake behaviour ( ?? community use )24 hr recall Immediate recall period, easy to obtain Relies on memory; requires skilled information; since interviewers interviewer; does not reflect the usual dietary intake ; tendency to over report administer tool & records the low intakes and under report high responses, literacy is not a intakes ( need for food list, std menu problem, respondent burden minimal; types; need for community based does not alter intake behavior; wide training ) memory; requires complexFFQs Inexpensive ; preferred for nutrients range of use Relies on with high day-to-day variability; does calculations to estimate frequencies; not alter intake behavior; lower requires literacy, doe not quantify respondent burden; epidemiological intake ( need for exhaustive food research to study diet-disease list; need for manual tally type relationships calculations)Food habit Rapid &low cost; does not alter intake may rely on memory; may requirequestionnaire behaviour trained interviewer ( need for food list; std menu types; community based training) Relies on memory; may requireDiet history No literacy needed; trained interviewer ( need for food list & community based training
Validation and Reliability of dietarymethods Validity - how well it measures what it purports to measure (accuracy) Reliability – how well it agrees on retesting under the same conditions (consistency) Assessment of reliability is feasible , validity poses a problem Gold standard established – dietary record/direct observation of subject’s consumption Reference for validation
SOURCES OF ERROR IN DIETARY ASSESSMENT METHODS (INDIVIDUAL INTAKES)Source of Weighed food Estimated 24 hr recall Dietary historyerror records food weight and FFQs recordsFCT /recipe + + + +booksFood coding + + + +Wrong weight _ + + +of foodsReporting error _ _ + +Variation of + + + _diet with timeWrong _ _ _ +frequencyModified ± ± _ _eating patternResponse bias ± ± ± ±Sampling bias + + + Ferro –Luzzi in FAO, 2002 Source: Anna +
Ranges of nutrient intake goals (WHO/FAO, 2003) Dietary factor Goal (% of total energy ) Total fat 15-30% Saturated fat < 10% PUFA 6-10% Trans fatty acids < 1% Total CHO 55 -75% Free sugars 10% Protein 10-15% Cholesterol <300mg/d Na Cl <5g/d Fruits and vegetables at least 400 g/d Total dietary fibre From foods (40g/d)Non starch polysaccharides (NSP) From foods (whole grains, F&V)
Easy way to count your calories(Measures providing 100 kcal Cereals : 30 g ( 1/5 cup) Egg : 60 g ( 1 medium size) Bread : 40 g ( 2 slices) Chicken : 90 g ( 3 small Pulses : 30 (2 Tbsp) pieces) Leafy vegetables (sak): 250 g Mutton: 85 g ( 2 small bunches) Fish (lean) 100 g Other vegetables : 400 g (4 Fish (fatty) 60 g cups) Shrimp : 30 g Potato : 100 ( 1 cup) Prawn : 100 g Nuts/oilseeds : 20 g (handful) Sugar : 25 g ( 5 tsp) Fruit : 150 g/ 1-2 fruits Spices : 40 g ( 6 tsp) Milk/Curd :150 ml ( 1 cup) Oil/ghee : 10 g (2 tsp) Butter milk (ghol) : 670 ml ( 4 Butter : 15 g (1 Tbsp) cups) Channa/paneer/cheese : 30 g (1 pkt)
Conclusions Need to use core indicators linked to food security & nutrition outcomes; Identify food and nutrition vulnerability through information on food consumption patterns Need to obtain information on intra household distribution of food for accurate assessment of individual intakes; Differential nutritional status associated with differences in morbidity or illness or other factors within HHs provides valuable information on food distribution Knowledge of HH food allocation patterns and underlying reasons for food / diet related behaviour, so that effectiveness of nutrition interventions can be improved.
Conclusions Choice of method : Information needed, resources available Food/nutrients of primary interest, group/vs individual data, absolute /vs relative intake , population characteristics Include statistical expertise while designing survey and questions Can provide qualitative data on dietary intake of HH Can be combined with other methods to obtain individual quantitative data When absolute vs relative estimates are required, food record, 24 dietary recall are methods of choice For day –to-day variability – FFQ useful DD – dietary patterns/habits/semi qualitative can be quantified Dietary assessment is essential to identify populations at risk Useful for informing and developing appropriate policies