Household food consumption methods measure all food and beverages available for consumption by a household/ family group, during a specified time period. The following methods can be used-food accounts, list recall method, inventory method, food records, telephone surveys, actual chemical analysis of the diet etc.
- Food account Method: A food account consists of a daily record, prepared by the house holder, of all food entering the household, either purchased, received as gifts or produced for household use, during a specified period usually seven days. Quantities of each food item are recorded. Generally no account is taken of food and beverages consumed outside the home or food discarded as plate waste, spoilage or fed to pets. This method is relatively inexpensive.
- Inventory method: The inventory method aims at recording acquisitions and changes in the food inventory of households during the survey period. An inventory is prepared of the weights and type of all food commodities in the house at the beginning and end of the survey period, which is generally for one week.
- Weighment method: This method can be used for weighing of raw as well as cooked foods. In community surveys, usually the raw foods rather than cooked foods are weighed, since it is easy and meets with lesser resistance from the households. Weighing of cooked food however is feasible and can be used for household dietary survey.
Foods are actually weighed using on accurate balance. A balance with standard weights and volumetric measures form the main equipment and a structured diet schedule is the study instrument.
In order to obtain the representative picture of the diet, investigator should keep in mind the following do’s and don’ts.
Do’s:
- Every day make at least two visits. One in the morning and the other in the evening before actual cooking is begun by the house wife.
- Weigh only the edible portions of raw foods.
- Make note of correct age, sex and physiological status and activity of each member in the household, who is partaking meals on the day of survey.
- Account for guests, visitors, pets and the absentees in the computations.
- Collect additional information on socioeconomic status of the household and culinary practices i.e., the way the food is cooked, preserved and consumed.
Don’ts:
- Avoid fast and festival days.
- Do not make false promises of incentives or raise hopes to obtain co-operation from the households.
Results of the weighment method employed at household level are expressed usually as intake of foods in grams per Consumption Unit or per person per day. Foods are converted to nutrients by referring to food composition tables, which provide information on quantities of different nutrients. The nutrient intake thus can be expressed per Consumption Unit (CU) or per capita.
Consumption Unit (CU): On the basis of energy requirement of the body for carrying out its legitimate functions of growth, wear and tear, maintenance of body weight etc, arbitrary calorie coefficient values have been assigned for person’s different age, sex and activity group. The value assigned for adult male during sedentary work is one (unit). The energy requirement (RDA) per CU is 2400 kilocalories. For other age, sex and activity/physiological groups, the values assigned form a fraction of this unit as shown below.
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Group
|
Consumption Units( CU)
|
1
|
Adult male (Sedentary worker)
|
1.0
|
2
|
Adult Male (moderate worker)
|
1.2
|
3
|
Adult Male (heavy worker)
|
1.6
|
4
|
Adult Female (Sedentary worker)
|
0.8
|
5
|
Adult Female (moderate worker)
|
0.9
|
6
|
Adult Female (heavy worker)
|
1.2
|
7
|
Adolescent (12-21 years)
|
1.0
|
8
|
Children ( 9-12 years)
|
0.8
|
9
|
Children ( 7 to 9 years)
|
0.7
|
10
|
Children ( 5 to 7 years)
|
0.6
|
11
|
Children ( 3 to 5 years)
|
0.5
|
12
|
Children ( 1 to 3 years)
|
0.4
|
Consumption units for computing calorie requirement of different groups
Intake per CU per day: This is calculated using the following formula
Intake per CU per day (g or ml) =
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Demerits:
- Calorie co-efficient values used in computation of intakes are considered to hold good only for calories and hence, their applicability to other nutrients like proteins, vitamins etc is not valid.
- Precise consumption level of specific age and physiological groups, within in the family cannot be assessed.
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