12 Diet Survey

Dr. Mallikarjuna Rao

Contents:

1. Introduction
2. Need for the diet survey
3. Units of diet survey
4. Methods of Diet survey
5. Assessment of Dietary Intake (Household/individual level)
6. Individual Dietary Intake Survey (24-hour Recall) Summary

Learning Objectives:

•  To discuss the various types of diet survey;
•  To plan and organize diet survey; and
•  To conduct diet survey at different levels.

1. Introduction

Adequate food and sound nutrition are essential for good health. Not only are they crucial for human survival but also key factors in the prevention and recovery from illness. They are prerequisite for improving quality of life of people. Since diet has far reaching influence on health, it is essential to have an idea of the dietary pattern of the community. Information on food consumption patterns is also essential for assessing the food needs of population groups at national/regional level.

2. Need for diet survey

It helps to assess the consumption pattern of the people both in terms of quality and quantity. It also helps to know the inadequacies in the existing dietary pattern and formulate suitable intervention strategies. To find association between diet and disease, such as nutritional deficiency disorders and diet related chronic diseases including diabetes, hypertension, obesity etc,

3. Units of diet survey

The population units to be covered for diet survey may be classified under the following headings, namely at:

• National or regional level- studies covering large groups of population/the entire country or region.
• Institutional  level-  homogenous  groups  of  population  residing  tin  institution  like  hostels, hospitals, jails etc.,
• Family /individual level

4. Methods of Diet survey National level

To carry out the surveys at the national level, the usual method employed is by computing ‘Food Balance Sheets’. By food balance sheets (FBS) we mean the quantities of various foods available for consumption at the retail level per head of population calculated from the total net supply figures.

The data from FBS thus tell us the food available at country (national) or regional level, but not the food actually consumed by the people.

Institutional level: e.g. Hostel, Orphanage, Hospital, Jail.

Two methods may be employed at the institutional level and they are:

• Inventory method (Food list method)
• Actual weights (raw and cooked)

Inventory method: This method is often employed in institutions like hostels, army barracks, orphanages, homes for the aged etc., where homogenous groups of people take their meals form a common kitchen. In this method the amounts of foodstuffs issued to kitchen as per the records maintained by the warden, are taken into consideration for computation of consumption. No direct measurement or weighing is done. A reference period of one week is desirable.

Stocks at the beginning of the week – stocks at the end of the week

Total No. of inmates partaking the meal× No. of days

Actual Weights: In this method the total raw foods ready for cooking are weighed taking into consideration the wastage of food. In the same way the total food cooked are also weighed. This procedure is repeated for at least seven days.

To assess the intake per person per day the following procedure is adopted:

5. Assessment of Dietary Intake (Household/individual level)

Household Diet survey

Household diet survey provides information on food and nutrient intakes of that household for a given day, preferably for previous 24 hours (recall method). Raw equivalents of all the ingredients used for preparation of foods on the reference day are weighed and recorded. Also demographic particulars of the individuals who have participated in the meal/s are also recorded. The intake of various food stuffs are computed and expressed as average per CU/day, as follows:

                                                                      Total Raw amount used (g)

Average Intake per C.U/day (g) =   —————————————————-

                                                                  Total C.U of HH (Consuming the food)

Consumption Units of individuals

The energy requirement of an adult male, aged 20 to 39 years, weighing 60 Kg., doing sedentary work (Reference Indian adult man) is taken as “one consumption unit” and calorie co-efficient for others are proportionately worked out on the basis of age, sex, physiological status and activity as indicated below:

6. Individual Dietary Intake Survey (24-hour Recall)

Individual intake diet survey is carried out for the previous 24 hours. This provides scope for assessing intra family distribution of food, and there by compute food & nutrient intake of individuals by age, gender, physiological status and activity.

General Guidelines for carrying out diet survey in the community

The housewife, who cooks and serves food to the family, will be the respondent. The purpose of the visit and the importance of the survey must be explained to her before initiating the survey, so as to elicit factual information. The investigator gets familiarized with the local measures used and their corresponding weights and volumes.

In the 24-hour recall diet survey, the all the foods consumed by the family members during the previous day consumed including those cooked in the house as well as those from out side, should be recorded.

Reference day of diet survey should not be a festival day or a day of celebration of any kind in that family, as the food consumption pattern on these days would be different from the normal. In such a case, the diet survey should be carried out in the next house.

Name, age, sex and other particulars of all the members, who have taken part in meals on that day should be entered in the proforma, chronological order. Particulars of guests, if any, who participated in the meals, should be included and the names of those family members who did not participate in the meals should be deleted.

If any child, pregnant & lactating women have participated in the supplementary feeding Programmes such as ICDS MDM, etc., on the reference day, the particulars of the same (such as the name/type/quantity consumed by each beneficiary) should be recorded. Efforts should be made to elicit information regarding the composition of the supplement from the ICDS worker concerned with that programme, in that village.

Discourage presence of neighbours as spectators at the time of collecting the dietary information, so that the housewife gives correct information.

A set of standardized cups and grocer’s balance are used to record the intakes. The cups are numbered from 1 (largest cup) to 12 (smallest cup). The cups are used to help the housewives to recapitulate the volumes of the preparations cooked and served to the individual members in the family.

Some Important Steps for carrying out Individual Intake Diet Survey:

Record all the food preparations that were made at home or bought from outside and consumed on the previous day from early morning till night.

To start with, information of meal pattern, the menu and the raw ingredients used for each preparation used, information on leftover food, if any, any and their subsequent consumption on the same day, should be recorded.

Record the names of all the ingredients and the raw amounts of each foodstuff used for each of the preparation. As far as possible, obtain the equivalent quantities of raw foods (such as cereals/pulses etc.) available in the house and weigh them in the grocer’s balance (supplied with the kit) and record the weights to nearest grams. This should be done after entering the menu of food preparations for whole day.

The total cooked volume of each of the preparations is recorded in terms of standardized cups. For this purpose the housewife may be asked to fill the vessel in which the preparation was made with water to the level up to which food was prepared. The volume of the cooked food is assessed by measuring this water with the standardized cups provided.

The quantity of each preparation consumed by each individual is assessed in terms of standard cups and is recorded accordingly.

Intake of preparations, such as roti/chapati, eggs, etc., is assessed by noting the total number of pieces cooked and number consumed by each individual.

Standard cups/spoons are used to assess the quantities of cooking oil, spices, sugar, etc.

Record the quantity of “left over” foods, if any, under “left over” column, with remarks such as, “consumed later in lunch/dinner,” or “next day” or “given to others” as the case may be.  If the leftover food is consumed later in the day, the same has to be entered under.

“Menu” column and particulars of individual quantities consumed should be recorded.

Whenever “left over” food of previous day is consumed by a household on the reference day, enter the particulars such as name of preparation, the ingredients and the raw quantities used, total cooked volume”, and individual quantities consumed on the reference day.

Ensure that the variation between the total quantity of food reportedly prepared and the total of the quantities distributed among the members, including the left-over, is less than 10%. In case of larger variation, repeat the entire exercise.

Example of volume of a standardized set of cups and spoons* is given below. It may be noted that the cups can be standardized in the respective institutions:

Computation of Individual Intakes of Raw Food Equivalents

Calculation of raw food equivalents

Intake of raw equivalents of different foods in each preparation by individuals is calculated as follows:

Food and Nutrient Intakes of Individuals

The average daily intakes of different foods by individuals will be calculated according to different age/sex, physiological status and physical activity groups. The median daily intake of various nutrients will be computed using food composition tables in ‘Nutritive value of Indian Foods. The intakes will be compared with ‘Recommended Dietary Allowances for Indians’ (RDI) suggested by the ICMR Expert Group.

Summary

A dietary assessment is a comprehensive evaluation of person’s food intake. Estimation of dietary intake focus on the amount food consumed by an individual or groups and can be used to assess adequacy of diet to meet the food and nutrient requirement. It also establish the presence of a link between dietary factor and a given health outcome and also to monitor the response of patient to manipulation of the diet in clinical setting.

Different units of diet survey include 1. At National level 2. At Institutional level 3. At family or individual level. Investigator has to select appropriate method for the purpose and target group of the study. Ultimately all survey methods are dependent on motivation, compliance and ability of subjects to report accurately their habitual food intake. Dietary assessment methods work best in combination with other methods for the assessment of nutritional status.