An individual’s nutritional status reflects the degree to which physiologic needs for nutrients are being met. The balance between nutrient intake and nutrient requirements for optimal health is shown in the figure. Nutrient intake depends upon actual food consumption, which is influenced by factors such as economic situation, eating behaviour, emotional climate, cultural influences, effects of various disease states on appetite, and the ability to consume and absorb adequate nutrients. Nutrient requirements are also influenced by many factors –including physiologic stressors such as infection, chronic or acute disease, fever, trauma; normal anabolic states of growth, pregnancy, or rehabilitation; body maintenance and well being; and psychological stress. When adequate nutrients are consumed to support the body’s daily needs and any increased metabolic demands, the person develops an optimal nutritional status. Appropriate assessment techniques can detect a nutritional deficiency in the early stages of development, allowing dietary intake to be improved through nutritional support and counselling before a more severe condition develops.
Most commonly, nutrient density is defined as a ratio of nutrient content (in grams) to the total energy content (in kilocalories or joules) ; Nutrient-dense food is opposite to energy-dense food (also called "empty calorie" food). According to the Dietary Guidelines for Americans 2005, nutrient-dense foods are those foods that provide substantial amounts of vitamins and minerals and relatively few calories. Fruits and vegetables are the nutrient-dense foods, while products containing added sugars, processed cereals, and alcohol are not.Second, nutrient density is defined as a ratio of food energy from carbohydrate, protein or fat to the total food energy. To calculate nutrient density (in percent), divide the food energy (in calories or joules) from one particular nutrient by the total food energy in the given food.Third, nutrient density is understood as the ratio of the nutrient composition of a given food to the nutrient requirements of the human body. Therefore, a nutrient-dense food is the food that delivers a complete nutritional package.
The relationship between anthropometric and dietary energy inadequacy is not symmetric as ill health can cause growth failure in the presence of adequate food access. Food intake often will be reduced owing to poor appetite in sickness even in the presence of adequate food supply; however in a stable situation, people will not be of adequate body size with inadequate food energy even if health is good. The implications are illustrated in the table. Treating this association by placing individuals in categories depends crucially on the cut offs and implies that the cut off of – 2 z score for W/A used in the illustration is related to energy intake below requirement ( i.e hunger). In this case the cut off may be approximately correct. Crucially in a steady situation there should be no one in inadequate energy – adequate weight category (note bottom left cell is equal to 0). It is not possible to maintain an adequate weight with inadequate energy. This may help relate the indicators to each other to some extent, referring again to the table. DES indicators should go in the same direction as anthropometric indicators. Need for combination of methods support individual dietary intake surveys, including qualitative methods from HIES surveys and other HH surveys such as DHS and UNICEF – MICS surveys
Topic 21 diet diversity
INTRODUCTION TO NUTRITION ANALYSIS : POLICY PARAMETERS Lalita Bhattacharjee Nutritionist Training Workshop on Analysis of Data for MeasuringAvailability, Access and Nutritional Status Assessment of Nutritional Status 14 -26 January 2012
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 stressors (infection, disease) and psychological stress
OPTIMAL NUTRITIONALSTATUS Source: Mahan and Stump, 2000
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)
WHAT IS DIETARY DIVERSITY Dietary diversity isa qualitativemeasure of foodconsumption thatreflects householdaccess to a varietyof foods and isalso a proxy fornutrient adequacyof the diet ofindividuals
HHDDS and IDDSMeasures no. of different food groups consumed over a given reference period i.e. 24 hours/1 dayHDD is also a proxy for HH socio economic status, whereas IDD is purely a proxy measure of an individual’s quality of diet.
WHEN TO MEASURE DIETARYDIVERSITYObjective TimingAssessment of the typical diet of When food supplies are stillHHs/individuals adequate (may be 4-5 mo after the main harvest)Assessment of the FS situation in During periods of greatest foodrural, agriculture based communities shortage, such as immediately prior to the harvest/immediately after emergencies or natural disastersAssessment of FS situation in non- At the moment of concern to identifyagricultural communities a possible food security problemMonitoring of FS/N programmes or Repeated measures to assessagricultural interventions such as impact of the intervention on thecrop/livelihood diversification quality of the diet, conducted at the same time of the year as te baseline (avoid interference due to seasonal factors)
Foods/food groups HDDS WDDS 9-group WDDS 13-group IYCF DD Q Food Group Q Food Group Q Food Group Q Food Group 1. Cereals 1,2 Starchy staples 1,2 Starchy staples 1,2 Starchy staples 2. White tubers & roots 4 Dark green leafy 4 Dark green leafy vegetables vegetables 3,4, Vegetables 3,6 Vitamin A rich fruits 3 Vitamin A rich 3,4,6 Vitamin A rich fruits & 5 & vegetables vegetables vegetables 5,7 Other fruits & 6 Vitamin A rich 5,7 Other fruits & vegetables fruits vegetables 5 Other vegetables 6,7 Fruits 7 Other fruits 8,9 Meat 8 Organ meat 8 Organ meat 11 Fish and other sea 9,11 Meat and fish 9,11 Meat and fish 8,9,1 Flesh foods food 1 10 Egg 10 Egg 10 Egg 10 Egg 12 Legumes, nuts & 12 Legumes, nuts & 12 Legumes, nuts & 12 Legumes, nuts & seeds seeds seeds seeds 13 Dairy 13 Dairy 13 Dairy 13 Dairy 14 Oils & fats 15 SweetsPracticalCondiments & 16 Exercise 3: Use of dietary diversity in food security and nutrition surveillance – Jillian L. Waid beverages
Methods for data analysis Cut offs :Not universally defined FANTA 2: Less than 5 ( out of 9 or 13 food groups) is inadequate Programmatically : Goal to raise the mean overall to the mean of the top third of the respondents
HDDS CalculationStep 1: Assign 1 if the food group/item consumed; 0 not consumed. Sum all the scores for various food groups. Sum will be between 0-12.Step 2: The average HDDS for the sample population Sum HDDS Total no. of households Setting HDDS Threshold: Option 1: From a baseline survey take the HDDS for the richest income tercile (33%) Option 2: From a baseline survey take HDDS of the upper tercile of diet diversity (33%)
Different Types of Childhood Malnutrition Normal height for ageChildren Wasted Stunted Underweight Normal Low weight for height Low height for age Low weight for age
Why is nutrition not improving? Knowledge: do people know what foods they should consume by age, sex, occupation, physiological status? Do families have the resources/motivation to convert knowledge to practice If food intakes (energy and nutrients) are adequate, could there be intervening factors e.g. illness Pre-disposing factors: maternal undernutrition seasonal food/income shortages, migration, illness outbreaks, hygiene/sanitation, emergencies Importance of under 2’s
Illustration of association between dietary adequacy and anthropometryPrevalence of % with % with Total underunder inadequate adequate ornutrition diet diet adequate% <-2SDs 20 10 30 nutrition% > -2SDs 0 70 70Total sample 20 80 100Note: 10% have adequate diets but are still undernourished due to other causes Source : Mason, 2002 in “Measurement and Assessment of Food Deprivation and Undernutrition”, FAO