Dietary

Assessment of dietary and nutrient intake
methods, limitations, application, food composition tables
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Introduction •Dietary assessment involves: omeasures quantity and quality of individual foods consumed one to several days or assessing pattern of food use during the previous days/months oconversion of amounts of foods into nutrients: uses food analysis (duplicate portions), food composition tables or nutrient databases tables or nutrient databases oevaluation of dietary intakes: comparison with recommended nutrient intakes •it is 1 of the 4 methods used to assess nutritional status  (other methods will be taught in HN 105, semester 2)
Biochemical assessment
Anthropometric assessment
Clinical/physical examination 2
Introduction
Dietary assessment •compared to the other 3 methods, it identifies the first stage of a nutritional deficiency •dietary intake of one or more nutrients is inadequate because of a: oprimary deficiency: low levels in the diet osecondary deficiency: conditioning factors interfering with digestion, absorption, transport, metabolism of nutrients (e.g. diseases, certain drugs, dietary components)
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Introduction Biochemical assessment measures levels of a nutrient or its metabolite in body fluids or other components that relate to nutritional status •can identify primary and/or secondary deficiencies otissue stores most sensitive to depletion become gradually depleted of nutrients, their metabolic products gradually depleted of nutrients, their metabolic products in body fluids or tissues (Static tests) ofailure of physiological or behaviouralfunctions dependent on that specific nutrient (Functional tests) e.g. change in activity of nutrient-dependent enzymes, taste acuity for zinc status, production of abnormal metabolite, etc
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Introduction Anthropometric assessment involve measurements of physical dimensions i.e. growth (weight, height or length [child <24mo.], head, chest, waist and hip circumferences, armspanor half span (for older people)and gross body composition i.e. fat, fat-free mass (mid-upper arm circumference, skin-fold thickness) mass (mid-upper arm circumference, skin-fold thickness) •basis: chronic imbalances between energy and protein intakes modify pattern of physical growth and relative proportions of tissues e.g. fat, muscle, total body water •can detect moderate, severe degrees of malnutrition •measurements vary with age, sex, degree of nutrition •provide information on past nutritional history 5
Introduction Principles of Anthropometric measures Weight regularly calibrated electronic scales, spring scales are less reliable; weigh in light clothes, no shoes read to the nearest 100 gm (0.1kg) Height Height portable infant/child/adult wooden length board with a movable head piece subject stands erect, bare footed on a stadiometer with a movable head piece. The head piece is leveled with skull vault record to the nearest 0.5 cm.(or length)
Introduction
Principles of Anthropometric measures Length portable infant/child/adult wooden length board with movable head piece; subject lies in supine (recumbent) position (child <24 mo.), bare footed record to the nearest 0.5 cm record to the nearest 0.5 cm Head circumference subject stands relaxed, left side facing the measurer, line of vision is perpendicular to the body; non-stretch tape is placed  just above supra-orbital ridges covering most prominent bulge over the occiputwhich gives maximum circumference; record to the nearest millimeter 
Introduction Principles of Anthropometric measures Waist circumferenceis measured at the level of the umbilicus to the nearest 0.5 cm. Subject stands erect with relaxed abdominal muscles, arms at the side, and feet together, measurement should be taken at the end of a normal expiration Hip circumferencemeasured at the point of greatest circumference around hips & buttocks to the nearest 0.5 cm subject should be standing and the measurer should squat beside him •both measurements should taken with a flexible, nonstretchable tape in close contact with the skin, but without indenting the soft tissue
Introduction
Clinical assessment uses medical history and physical examination to detect signs associated with malnutrition i.e. observations made by a qualified examiner and symptoms i.e. manifestations reported by the patient •signs & symptoms are often non-specificand only develop during advanced stagesof nutritional develop during advanced stagesof nutritional depletion; diagnosis of a nutritional deficiency should not rely exclusively on clinical methods •changes believed to be related to inadequate nutrition can be seen or felt in superficial epithelial tissue, especially skin, eyes, hair, buccalmucosa, in organs near the surface of the body (e.g. thyroid glands)
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Introduction Examples of physical signs indicative of malnutrition Normal appearanceSigns indicative of malnutrition
Hair:shiny; firm; not easily plucked
lack of natural shine; hair dull, dry; thin and sparse; hair fine, silky, and straight; color changes (flag sign); can be easily plucked
Gums:healthy, red, ‘spongy’ bleed easily, collapse of gums
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Gums:healthy, red, do not bleed, not swollen
‘spongy’ bleed easily, collapse of gums
Skin:no signs of rashes, swellings, dark or light sports
dryness of skin (xerosis); sandpaper feel of skin (follicular hyperkeratosis); flakiness; swollen and dark; red swollen pigmentation of exposed areas (pellagrous dermatosis); black and blue marks resulting from skin bleeding; lack of fat under skin
Methods I.Food Balance Sheets(national level) II.Household consumption and family budget III.Individual dietary data

choice of dietary method depends on purpose, timescale, population characteristics, resources i.National food planning and administration ii.Epidemiological surveys (relation between nutrition ii.Epidemiological surveys (relation between nutrition (diet) and health iii.Toxicological studies (food exposure to biochemicals, toxins, other contaminants) iv.Metabolic studies (fate of nutrients in the body) adequacy vs. requirements = amount of food eaten food supply = produced, purchased, price of food, incomes chronic diet condition = past intakes, dietary pattern 11
Methods I.Food Balance Sheets(FBS): assess food available for consumption at national level) •indicate diversity and adequacy of food supply •published by FAO annually, 95 food commodities are covered; give trends & comparisons; identify countries/regions most likely to be at greatest risk for low nutrient intakes •calculated from annual food production, changes in food stocks, •calculated from annual food production, changes in food stocks, imports, exports and other food uses within the country oAvailable (production+import+stocks+……. oUses (export+seed+feed+manufacture+waste+losses+nonfood+…… oPer capital food supply: available food (kg)/population oDaily supply (g/day): divide by 365 days oDaily energy supply: multiply amount of daily supply by food composition values 12
Methods Limitations of Food Balance Sheets •quality differs depending on sources of data •not easy to quantify food waste, food traded across countries and other food uses (e.g. local brew) •lack information on how food supplies are •lack information on how food supplies are distributed between population groups •not suitable for analysis of quality of diet relative to nutrient recommendations •data may be inflated for political reasons (actual food available is low vs. authority wishes for food to be available)  13
Methods II.Household consumption and family budget •amount of food available for consumption in the household; food consumption per capitais calculated irrespective of age, sex •not easy to measure consumption outside of home and food distribution by individuals  and food distribution by individuals  Methods used (mostly over 7 days, or longer): a.food account: daily record of all foods brought into the household (produced, purchased, gifts) during a specific period; no records of foods consumed outside the home, waste/spoiled/discarded/pets; respondent burden is low; inexpensive; diet not altered  14
Methods II.Household consumption and family budget b.inventory: record acquisitions + changes in food inventory i.e. food (+ weight) available (including reserves/stored) at beginning and end of study period, number + age of persons is recorded, wastage factor 10% of edible portions is applied if wastage factor 10% of edible portions is applied if not collected separately; high respondent burden, normal pattern distorted

Methods II.Household consumption and family budget c.list-recall: interviewer uses a list of major food items (likely to be consumed) in a structured questionnaire to help respondents recall amount, price or value of all foods used in household within specified period; more info is collected: age, sex, no. of meals eaten at home & info is collected: age, sex, no. of meals eaten at home & away, income, SES; one assessment used d.household food record: interviewer/caretaker weighs foods available for consumption over 1 week, detailed description, cooking methods, ingredients+amountsin composite dishes & final dish, adjustments (visitors, foods outside home); more accurate, high respondent burden, normal pattern may be altered 16
Methods
III.Individual dietary data •Recall of past food intakes: 24-hour food recall, Food frequency questionnaire (FFQ), semi-quantitative food frequency questionnaire (sFFQ), Dietary history •Recording of present food intake: Weighed food records, Estimated food records records, Estimated food records Additional information to collect which may influence diet: food production, prices, marketing and distribution; food situation (availability, accessibility), socio-economic status, demography (birth order), culture [beliefs, habits], morbidity, etc18
Methods
III.Individual dietary data Major steps in assessment: •Record past or present food intakes •Convert amounts of foods into nutrients use food analysis (duplicate portions), food use food analysis (duplicate portions), food composition tablesor nutrient databases •Evaluate dietary intakes compare intakes with recommended energy and nutrient intakes (adequate/inadequate?); dietary intake figures alone can never prove whether people are adequately fed 19
Methods
24-hour food recall •trained interviewer asks the subject to recall all foods & drinks consumed in the previous 24 hours ofoods/meals/ingredients are described, portions/amounts consumed are estimated oestimation tools include household or standard measures (mugs, cups, calibrated spoons, cups, bowls, measures (mugs, cups, calibrated spoons, cups, bowls, cylinders), food models, life-size photographs or drawings of different portion sizes
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Methods
24-hour food recall •requires: i.list of edible portion of foods(portion that can actually be eaten e.g. 0.68 [68%] of ripe banana is edible) ii.cooked-to-raw conversion factors (change due to cooking) e.g. raw rice 85g, cooked rice 189g, raw-cooked factor 85/189=0.45, cooked-raw rice 85/0.45=189g iii.weights and measurements of foods and preparations shows average weight of different sizes of foods and preparations available in the study communities used when you can not weigh preparations for which it is not possible to obtain ingredients list 21
Methods
24-hour food recall •quick, easy, depends on short-term memory •multiple 24-hour recalls on non-consecutive, representative days are needed to assess usual intake (i.e. evenly distributed days: wkday-wkend, ill-well, festival-normal) •subject given no prior warning of interview •subject given no prior warning of interview •recall is by interview (in person, by telephone) in a quiet, relaxed atmosphere, preferably athome to ensure accurate estimation of portion size using household utensils •interviewer should ask neutral questions, need to be aware of combinations of food likely to be eaten together in order to probe for items not mentioned
Methods Additional questions may include: •was intake unusual? In what way [illness, recovery, festival, celebration, etc]? •intake of vitamin/mineral supplements? Which ones? How frequently? •where was food eaten [home, canteen, school, etc]? •where was food eaten [home, canteen, school, etc]?
Methods Exercise: Please tell me what you ate and drank yesterday from the time you woke up to the time when you went to sleep. Probe: •Time (e.g. 0800, etc) and meal occasion (e.g. breakfast, snack, lunch, supper) •Type of meal (e.g. bean stew, porridge, etc) or fluid (e.g. orange juice, soda, etc) orange juice, soda, etc) •Ingredients used to prepare the meal or added to alreadyprepared meal (e.g. refined maize flour, sugar, etc) •Amount(in household measure) of ingredients used to prepare the meal/fluid or added to meal/fluid •Amount(in household measure) of total meal/fluid prepared, served to child, consumed and left uneaten 25
Methods Results of 24-hour food recall can be used to: oDetermine nutrients intake (requires calculations) oAssess dietary diversity scores (DDS): FAO (2010) guidelines for measuring household DDS and individual DDS •categorisemeals/ingredients into 15 or 16 food groups; find total number of groups
Type of food or meal1=Yes0=No Cereals e.g. maize, sorghum, finger millet, pearl millet, wheat Vitamin A-rich (red/yellow/orange) vegetables & tubers e.g. pumpkin, carrots, orange-fleshed sweet potatoes Other roots, tubers e.g. cassava, potatoes, g/bananas
Dietary diversity (FAO 2010 guidelines) Cereals e.g. maize, sorghum, finger millet, pearl millet, wheat Nuts and oilseeds e.g. ground nuts, sunflower, pumpkin seeds Vitamin A-rich (red/yellow/orange) vegetables & tubers e.g. pumpkin, carrots, orange-fleshed sweet potatoes Animal milk, milk products Eggs Other roots & tubers e.g. cassava, potatoes, sweet-potatoes, gr/bananas Organ meats e.g. liver, kidney Flesh meats e.g. beef, pork
Green leafy vegetablesOther vegetables and fruits e.g. tomato, onion, eggplant Vitamin A-rich (red/yellow/orange) fruits e.g. mangoes, papaya, 100% fruit juice made from these Fish, sardines, or other sea foods Oil, fat, ghee used for cooking Legumes e.g. beans, peas, cowpeas, pigeon peas, green grams, soya bean Sugars/sugary products,honey, sweetened drinks, sweets, chocolates, cookies, cakes Spices, condiments, beverages e.g. salt, coffee, tea, alcoholic beverages
Methods Food frequency questionnaires (FFQ, sFFQ) •from a list of food items(questionnaire) subject is asked to indicate how frequentlythey were eaten (+ quantity) for a specific period[day, week, month] •FFQs differ by 1)  food lists [if interested in total diet or specific nutrient-rich foods], 2)  response intervals [for specific nutrient-rich foods], 2)  response intervals [for specifying frequency of use per day, week, month] •foods can be grouped on the basis of principal nutrients •if food list is limited, it will not reflect total food intake •if food list is too extensive, it may be tedious to complete 
Methods Food frequency questionnaires (FFQ, sFFQ)
Methods Food frequency questionnaires (FFQ, sFFQ) •not costly, easy to use [interview, self-administered] •needs updating of new food products (e.g. cultural, commercial) to keep up with changing dietary habits •need to be validated against a reference measure of known accuracy and pre-tested before study known accuracy and pre-tested before study •FFQ is considered descriptive, qualitative tool
Methods Food frequency questionnaires (FFQ, sFFQ) Limitations:memory bias due to long-term recall of food use •respondent burden due to number & complexity of foods listed and quantification procedure; longer food lists and longer recall period may lead to overestimation of intakes •questionnaire can be too long and errors can occur in estimating serving size(sFFQ) •quantification of portion sizes may be less accurate •development & testing of food list takes much time

Methods
Dietary history trained interviewer estimate total food intake & usual meal pattern over a long period of time (1 mo., 6 mon., 1yr) i.interview on usual daily pattern with quantities in household measures ii.cross checking/verifying information in (i) using detailed list of foods iii.interview food intake in the past 3 days To be successful, subjects need a regular dietary pattern and a good memory; this may hinder getting a representative sample Data can assess relative average intakes of groups of people
Methods Dietary history: Limitations •labourintensive, time consuming •high respondent and interviewer burden •usual food intake & amounts may be inaccurate •need well trained interviewer •memory bias due to long recall •memory bias due to long recall •respondents must be highly cooperative •compared to other methods, it over-estimates intake
Methods Weighed food records and Estimated food records •describes individual current intake; considered to be gold standard methods for food intake •in weighed records, respondent is taught to weigh (using a scale) and record food and its  weight before eating and left-overs before eating and left-overs omay not be feasible in population studies •in estimated records, respondents do not weigh but keep records of portion sizes of foods they eat on ≥ 1 days oportion sizes described in household measures
Methods Limitations of weighing/estimated food records •respondents must be literate, highly cooperative, conditions must allow weighing/records •normal eating habits may be changed by recording process •time consuming, high respondent burden due to record •time consuming, high respondent burden due to record keeping •foods eaten away from home may be less accurately reported
Limitations of dietary methods Each method has strengths & limitations •it is essential to consider purpose/objectives, precision (sample size, number of days to be studied), resources ocombination of two methods is more informative ogeneral guide: no more detailed, no more burdensome, no more expensive than necessary •limitations arise due to sampling bias, response bias, •limitations arise due to sampling bias, response bias, use of food composition tables instead of food analysis data oerrors associated with the nature of the method & abilities of respondents are difficult to control: portion size estimation, recall/memory error, day-to-day variation 
Limitations of dietary methods www.chempapy.blogspot.com•it is important to clarify detailed format of selected method (i.e. standard procedures) •it is crucial to conduct a pre-test or pilot study before the main study
Application •Define objectives, choose dietary assessment method, consider type of respondents •Prepare data collection tools [e.g. questionnaire, conversion factors, food weights, etc] •Plan for equipment, etc [collect, hire, purchase] •Train on the method’s standard procedures •Train on the method’s standard procedures •Pre-test and/or validate the tools •Interview [show respect, explain importance of the task, aim to gain cooperation] •Enter data in computer, analyse and interpret [various statistical procedures are applied in analysis]