Presentation on theme: "DIETARY ASSESSMENT By Lalita Bhattacharjee Nutritionist Training on Assessment of Nutritional Status 18-22 December 2011 Date : 21 December 2011 Venue:"— Presentation transcript:
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 Disaster Management and Food and Agriculture Organization of the United Nations (FAO) with the financial support of the EU and USAID.
Whoever was the father of a disease, 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 NUTRITIONAL STATUS Source: Mahan and Stump, 2000
DIETARY ASSESSMENT AND NUTRITIONAL ASSESSMENT : KEY TERMS A DIETARY ASSESMENT : comprehensive evaluation of a person's 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 individuals brief socio economic background, medical history, dietary, anthropometric, biochemical, clinical data and drug –nutrient interactions NUTRITIONAL STATUS : measurement of the extent to which an individuals 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 stressors (infection, disease) and psychological stress
Dimensions and methods for assessing food security and under nutrition MethodsAvailability of food Access to food Consumption of food Utilization of nutrients FAO Method Household income & expenditure surveys Individual food consumption/ intake surveys Anthropometry Qualitative measures of food security
Development of clinical deficiency with corresponding dietary, biochemical and clinical evaluation
Methods of assessing dietary intake 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
SHARE OF FOOD GROUPS AS % OF DIETARY ENERGY SUPPLIES Source: Adapted from FBS, FAO, 2010
Relative dietary energy contribution (En%) of cereals and rice to Bangladesh diet Source/YearEnergy intake (kcal) Cereal (g) En % Rice (g) En % HIES 20052238 452 70% 440 68% HIES 20102318 442 66% 416 64%
DIETARY ASSESSMENT PRINCIPLES Adequacy : a diet that provides enough energy and nutrients to meet the needs according to the recommended dietary meet the needs according to the recommended dietary intakes/allowances (for healthy and active life) intakes/allowances (for healthy and active life) Balance : a diet that provides enough, but not too much of each type of food ( adequacy of basic food groups) Variety : a diet that includes a wide selection of foods within each food group (dietary diversity/ includes biodiversity – species, varieties, cultivars) food group (dietary diversity/ includes biodiversity – species, varieties, cultivars) Nutrient Density : a diet that includes foods that provide the Nutrient Density : a diet that includes foods that provide the most nutrients for the least number of calories most nutrients for the least number of calories (nutrient dense foods) (nutrient dense foods) Moderation : A diet that limits intake of foods high in sugar Moderation : A diet that limits intake of foods high in sugar and fat (nutrient intake goals/guidelines) and fat (nutrient intake goals/guidelines)
Methods of obtaining dietary intake data MethodAdvantagesDisadvantages Nutrient intake analysisAllows actual observation of food intake May yield inconsistent and subjective estimates of food consumption; possible variation in portion size Daily food record or diaryProvides daily record of food consumption; can provide information on quantity of food; how food is prepared; and timing of meals and snacks Variable literacy skills of participants; requires ability to measure or judge portion sizes; actual food intake possibly influenced by the recording process; questionable reliability of records Food frequencyEasily standardized; can be beneficial when considered in combination with usual intake; provides overall picture of intake Requires literacy skills; does not provide meal pattern data; requires knowledge of portion sizes 24 Hour RecallQuick, easyRelies 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 : DAY MealFoods ( list )Amount eaten How prepared Where eaten (home, work, etc) Breakfast Snack Lunch Tea Dinner Food supplements : Name…… (cans/d) Vitamins/minerals supplement :….
Assessment of individual intakes Diet 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
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 intakes : 24 dietary recall
Assessment of individual intakes 24 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 individual intakes Food 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/d1/d3-6 times/wk 1-2/wk2/mth or less Never Beef Fish Liver Poultry Eggs Dried beans Green leafy vegetables Enter other foods not listed that are eaten regularly 1.------------- 2. ------------- 3. -----------
Example of semi quantitative FFQ FoodMedium serving ServingHow often ? SMLDWMYN Apples, apple sauce 1 or ½ cup Banana1 medium Papaya¼ medium Water melon1 slice Orange1 medium Bel juice6 oz glass Coconut water4 oz glass Boroi½ bati
Relative risk of lung cancer according to categories of baseline carotenoid and fruit + vegetable intake Quintile of nutrient or intake/d (n) MedianRelative risk Carotenoids (mcg) 1 ( < 2770) ( 397)21701.00 2 ( 2770-3786) (364)32810.94 3 (3787 – 4988) (320)43440.80 4 (4989 – 6792) (276)57770.70 5 ( > 6792) (287)85770.72 P for trend < 0.0001 Fruits + vegetables (g) 1 ( < 116 ) 407801.00 2 ( 116-176) 3621470.88 3 ( 177 – 241 ) 3262070.79 4 ( 242 – 332) 2932800.71 5 ( > 332) ( 256)4150.64 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 HHs with children under 5s Rapid assessment survey (focus group interviews, selected target group interviews IYCF practices, Social customs and food beliefs, behaviours & intakes Key informants – community leaders, local shop owners or health personnel Small clusters of women 5-6 women sufficient for FGD development of culture -specific relevant food usage list Linking food intake data with weighing /measuring of children & mother Derive mothers BMI from standard tables
Strengths and limitations of dietary assessment methods Relies on memory; may require trained interviewer ( need for food list & community based training No literacy needed; Diet history may rely on memory; may require trained interviewer ( need for food list; std menu types; community based training) Rapid &low cost; does not alter intake behaviour Food habit questionnaire Relies on memory; requires complex calculations to estimate frequencies; requires literacy, doe not quantify intake ( need for exhaustive food list; need for manual tally type calculations) Inexpensive ; preferred for nutrients with high day-to-day variability; does not alter intake behavior; lower respondent burden; epidemiological research to study diet-disease relationships FFQs Relies on memory; requires skilled interviewer; does not reflect the usual dietary intake ; tendency to over report low intakes and under report high intakes ( need for food list, std menu types; need for community based training ) Immediate recall period, easy to obtain information; since interviewers administer tool & records the responses, literacy is not a problem, respondent burden minimal; does not alter intake behavior; wide range of use 24 hr recall High participation burden; requires literacy; may alter intake behaviour ( ?? community use ) Does not rely on memory; open endedFood record LimitationsStrengthsMethod
Validation and Reliability of dietary methods 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 subjects consumption Reference for validation
SOURCES OF ERROR IN DIETARY ASSESSMENT METHODS (INDIVIDUAL INTAKES) Source of errorWeighed food records Estimated food weight records 24 hr recallDietary history and FFQs FCT /recipe books ++++ Food coding++++ Wrong weight of foods _+++ Reporting error__++ Variation of diet with time +++_ Wrong frequency___+ Modified eating pattern ±±__ Response bias±±±± Sampling bias++++ Source: Anna Ferro –Luzzi in FAO, 2002
Dietary factorGoal (% of total energy ) Total fat15-30% Saturated fat< 10% PUFA6-10% Trans fatty acids< 1% Total CHO55 -75% Free sugars10% Protein10-15% Cholesterol<300mg/d Na Cl<5g/d Fruits and vegetablesat least 400 g/d Total dietary fibreFrom foods (40g/d) Non starch polysaccharides (NSP)From foods (whole grains, F&V) 20g/d Ranges of nutrient intake goals (WHO/FAO, 2003)
Easy way to count your calories (Measures providing 100 kcal Cereals : 30 g ( 1/5 cup) Bread : 40 g ( 2 slices) Pulses : 30 (2 Tbsp) Leafy vegetables (sak): 250 g ( 2 small bunches) Other vegetables : 400 g (4 cups) Potato : 100 ( 1 cup) Nuts/oilseeds : 20 g (handful) Fruit : 150 g/ 1-2 fruits Milk/Curd :150 ml ( 1 cup) Butter milk (ghol) : 670 ml ( 4 cups) Channa/paneer/cheese : 30 g (1 pkt) Egg : 60 g ( 1 medium size) Chicken : 90 g ( 3 small pieces) Mutton: 85 g Fish (lean) 100 g Fish (fatty) 60 g Shrimp : 30 g Prawn : 100 g Sugar : 25 g ( 5 tsp) Spices : 40 g ( 6 tsp) Oil/ghee : 10 g (2 tsp) Butter : 15 g (1 Tbsp)
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 and programmes to improve nutritional status