Purpose

During 1942 and 1943 the Ministry of Health undertook a vitamin feeding test with elementary schoolchildren in several English towns in order to see the effect upon general health of the daily intake of multivitamin capsules over a lengthy period of time. Supplementary to this experiment, it seemed to be advisable to know exactly how these children were fed, and to estimate the nutritional value to these children of their ordinary weekly diet. The best medium for discovering this latter point was felt to be in the form of a survey. The Ministry of Health requested the assistance of the Wartime Social Survey at this stage, which undertook the dietary survey based upon a random sample. Firstly, of the English towns in which the Ministry of Health was continuing to supplement schoolchildren’s diets, two were chosen for the dietary survey. The towns expressly picked, in that their history was one of widespread unemployment during the depression, were Salford, a cotton town, and Stoke-on-Trent, the centre of the pottery industry. Secondly, a random sample was taken of the schoolchildren involved in the Ministry of Health experiment in these two towns, totalling 426 children.

The survey took place in September 1943 and again in March 1944, coinciding with the Ministry of Health experiment.

The experiment was approached with four aims in view:

The Method

It was not easy to decide what method to use. As one of the aims was to examine the diet of a fairly large number of children, the weighing method seemed rather difficult and cumbersome to be used by the average mother. To take only an inventory of the food eaten was unsatisfactory, as quantitative information on the food intake was needed. To solve this difficulty, Dr. Bransby of the Ministry of Health suggested a method with which he had experimented in 1942, measuring the food intake in homely measures, i.e. spoons, cups, etc.

The informant, in this case the child or his guardian, recorded the food eaten during a week.

The record was taken during the meal or immediately after.

The food was measured, wherever possible, in tablespoons or teaspoons of standard size. Foods such as vegetables, breakfast cereals, jam, sugar, milk etc. were easily measured in this way.

The size of other foods, such as meat, cheese, potatoes, tomatoes, cakes, pudding, was measured by comparing the actual size with the photographs on a chart, shown on the next page in a reduced scale.

Bread was measured in slices. The investigator collected about 8 slices on different days and at different meal-times. Each of these slices was weighed and the average weight for one slice was calculated.

Fat to be used as breadspread for the week was set aside; the amount was either weighed or estimated with the help of the investigator. If at the end of the week any fat was left, it was subtracted; if more was used, it was added to the original amount.

Food supplements such as Cod Liver Oil and Fruit Juices were recorded separately. Sweets and Chocolates were recorded in their weights or in bars of chocolate, number of sweets, together with a description of the kind of chocolate or sweets.

If the child took schoolmeals, this was also noted on the form.

Menus for each day during the period of the experiment were obtained from the schools. The schools were also asked to arrange for the measuring of food helpings each day, of a number of boys and girls of different age-groups.

The Informant kept his records on a single form of the following pattern:-

Form

Name of Informant:

Day of Week:

Food eaten during the day:

Breakfast: __________

Dinner: __________

Tea: __________

Supper : __________

Snacks: __________

He recorded the foods and their measure opposite each meal. Foods eaten in between meals were defined as “Snacks”. For each day of the week a separate form was used.

At the end of the week the information was transferred to a form such as the one used in the March Inquiry (shown on page 7) which is arranged in a way more suitable for analysis but too complicated to be handled by the Informants.

The investigation was carried out by 24 interviewers of the Wartime Social Survey, At their first visit they explained the purpose of the investigation and tried to obtain co-operation. If they succeeded, the procedure was explained and the Informant was asked to begin recording the next day.

The Investigator visited each Informant at least every other day, in many cases every day. Thus, as much supervision as possible was given to ensure the accuracy of measuring and recording.

Calculation of Nutrient Values

The nutrient intake of each child was calculated from the total amount of food he or she ate during the week. The weights used for the Standard Units of measure were found by experiment. The nutrient content of these weights was calculated from the values given in the “Chemical Composition of Food” (McCance & Widdowson 1940), supplemented by the values submitted to the Sub-Committee on Food composition of the Accessory Food Factors Committee of the Medical Research Council. (The weights used for the standard measurements, and the nutrient values given to the food are shown in Appendices 1 and 2).

In addition, samples of green vegetables were collected from homes and schools and analysed for their Vitamin C. content. The values obtained were averaged and this average was used for the evaluation of Vitamin C. content in green vegetables.

The translation of foods into their nutrient content was carried out on Hollerith machines. The principles of conversion of foodstuffs into nutrients using Hollerith machines do not differ from conversions carried out by hand. The great advantage of using mechanical means is the speed with which results can be obtained. The procedure is described in detail in Appendix 5.