Nevertheless , average net family income was appreciably higher in families with several children than in those with only one , many of which were incomplete families of younger parents with lower earnings , and of course with lower tax reliefs and no family allowances .sx The rise in net family incomes between 1954 and 1959 was greatest for childless couples , especially older couples ( probably because of the increase in retirement pensions ) , and somewhat greater in small than in large families .sx Expenditure and Consumption .sx 9 .sx Table 24 gives indices of domestic food expenditure per head and quantities purchased by older and younger couples and families with different numbers of children , with 1954 as the base year .sx The quantity index was calculated by dividing the expenditure index by a price index of the " Fisher Ideal " type , constructed for each group separately .sx The quantity index is thus confined to food purchases and takes no account of changes in free supplies .sx Compared with 1958 , the expenditure index for 1959 showed increases of 4 to 6 per cent for couples without children and those with one child , and much smaller changes for couples with several children .sx The quantity index , which has risen only slowly since 1956 , was almost unchanged in 1959 for couples with two or more children , but rose by 3 per cent in the older two-adult households and by 1-2 per cent for younger childless couples and couples with one child .sx 70 .sx Table 27 gives the total domestic food expenditure and value of consumption per person per week in 1959 in households of different composition .sx Percentage standard errors of these estimates are given in Table 10 of Appendix A. All types of household spent more than in the previous year except families with three children , whose expenditure had risen sharply in 1958 .sx The increases ranged from 2s .sx 7d .sx per person per week in the residual group of households with adolescents but no children and 1s .sx 8d .sx in older two-adult households to 4d .sx in the families with two and with four or more children .sx The value of free food was greatest ( 1s .sx 2d .sx to 1s .sx 4d .sx per person per week ) in the five types of household containing no children , and varied between 9d .sx and 11d .sx in households with children , except in the largest families for which the average was only 5d .sx , as in 1958 .sx In families with three children , the slight fall in expenditure was made good by an increase in the value of free food .sx The value of consumption per person per week in 1959 ranged from 41s .sx 7d .sx for younger childless couples to 19s .sx 5d .sx in families with four or more children ; in 1958 the range was from 40s .sx 3d .sx to 19s .sx 1d .sx 71 .sx Table 27 includes an index comparing the " price of energy " for the various types of household with that for all households in the sample .sx As in 1958 , younger couples paid some 12 1/2 per cent more per calorie than the national average , and families with four or more children 19 per cent less .sx The only substantial change was in families with three children , for whom the index declined from 91 to 88 .sx Table 27 also shows the corresponding values of an index which compares the prices paid by different types of household for the commodities constituting the average household diet in 1959 .sx For all foods the range was from 3.6 per cent above the national average in younger two-adult households to 4.8 per cent below in families with four or more children , compared with +3 .sx 6 to -5 .sx 4 per cent in 1958 and +2 .sx 8 to -2 .sx 6 per cent in 1957 .sx As with the price of energy index , the only noteworthy change was for households with three children , in which the index fell by 1.8 to 97.5 per cent of the average for all households in the sample .sx The price ranges for milk , cheese , sugar , bread and flour were very narrow .sx For most other foods younger childless couples paid the highest average prices and large families the lowest , the price gradients being steepest for carcase meat ( +7 to -7 per cent ) , " other " fish ( +8 to -11 ) , " other " vegetables ( +9 to -9 ) and beverages other than tea ( +12 to -16) .sx 72 .sx Details of expenditure and consumption per head are given in Tables 28 and 29 .sx Most groups obtained slightly less liquid milk than in 1958 , the greatest decrease ( from 5.24 to 5.08 pints per head per week ) occurring in younger two-adult households .sx Table 25 summarizes the changes in consumption of liquid milk ( including welfare and school milk ) between 1954 and 1959 by this group and by classified households containing children or adolescents .sx Consumption by younger childless couples declined throughout this period , but that of the smaller families was maintained except for the slight fall in 1959 .sx In the largest families , particularly those containing four or more children , there was a tendency for consumption to increase between 1955 and 1957 , and thereafter to decline .sx Graduated scales of family allowances were introduced in October 1956 , and the welfare milk subsidy was reduced in April 1957 .sx Despite appreciably higher average prices for natural cheese in 1959 than in the previous year , consumption fell only slightly in most groups ; the decrease was greatest ( from 3.68 oz .sx to 3.20 oz .sx per head per week ) for younger childless couples , who transferred much of their demand to cheaper varieties .sx 73 .sx All groups , except families containing three or more children , increased their expenditure on meat , but total consumption was much the same as in 1958 , although there was some replacement of beef ( which continued to be in short supply ) by mutton and lamb .sx All groups spent more on fish , and most increased their consumption , particularly of canned fish .sx Eggs were cheaper than in the previous year and consumption increased in nearly all groups despite fewer free supplies .sx 74 .sx All types of household substituted margarine for butter in 1959 because of higher butter prices , but all except the largest families continued to buy more butter than margarine .sx Total consumption of butter and margarine declined only in households containing children .sx The displacement of margarine by butter in 1958 , when butter was exceptionally cheap , appears to have had some lasting effect ; the average price of butter in 1959 was higher than in 1957 , yet butter purchases in 1959 , although smaller than in 1958 , were greater than in 1957 except in families with four or more children or with adolescents but no children .sx 75 .sx The smaller families and the residual groups of households containing children reduced their consumption of sugar and of preserves , but in all other types of household a decline in purchases of the one was accompanied by an increase in consumption of the other .sx 76 .sx Most groups spent slightly less on potatoes than in the previous year , but consumption was maintained except in families with more than one child and in the unclassified households with children or adolescents .sx All groups except families with four or more children or with adolescents but no children consumed more fresh green vegetables , especially in the first half of the year , although most reduced their consumption of other vegetables .sx Purchases of quick-frozen peas and beans generally increased , but extremely wide group differences persisted , the averages ranging from 0.1 oz .sx per head per week in families with four or more children to 0.9 oz .sx per head in younger two-adult households ; average consumption by older couples and other wholly-adult households was 0.5 oz .sx per head per week .sx The two latter groups consumed much smaller quantities per head of canned vegetables and canned and bottled tomatoes than any other group , and much smaller quantities of canned and bottled fruit than younger childless couples ; in households containing children , consumption of canned fruit fell off sharply with increasing family size , but there was no regular gradation in purchases of canned vegetables and canned tomatoes .sx All types of household benefited from the improved supplies and lower prices of fresh fruit compared with 1958 , but the increase in consumption was least in families containing children .sx 77 .sx Total bread consumption was virtually unchanged , although most types of household bought less white bread and more rolls and speciality breads than in 1958 .sx Most groups increased their purchases of puddings , cakes and biscuits , but obtained less flour .sx 78 .sx Regression estimates of the expenditure on different commodities attributable to the adult couple and each additional child in a selected group of households consisting of childless couples ( both under 55 ) and couples with different numbers of children were given for 1952-56 in Table 39 of the Annual Report for 1956 .sx The younger childless couples are broadly comparable in age and family income with the family households , so that differences in food expenditure may be associated with the presence of children .sx The analysis has been repeated for 1957 , 1958 and 1959 , but the results will not be given 6in extenso .sx Household food expenditure in 1959 averaged 80s .sx 9d .sx for younger couples and 92s .sx 10d .sx , 102s .sx 0d .sx , 111s .sx 9d .sx , and 126s .sx 3d .sx for two-adult households containing respectively one , two , three and four or more ( average 4.64 ) children under 15 .sx From a straight regression line fitted to these averages , the basic element in household food expenditure associated with the adult couple is estimated at 81s .sx 11d .sx and the average increment for each additional child as 9s .sx 11d .sx Table 26 gives similar regression estimates for previous years .sx The effects of price rises are roughly eliminated by expressing the average expenditure associated with a child as a percentage of that associated with an adult couple .sx The relative expenditure per child declined from 1952 to 1956 , but rose in 1957 when the subsidy on welfare and national dried milk was reduced ; since 1957 it has again declined .sx Most of the average expenditure associated with a child was on cereal foods , potatoes and milk ; for fresh green vegetables , fruit , cheese , fish and carcase meat , the incremental expenditure was slight .sx Energy Value and Nutrient Content .sx 9 .sx Table 30 shows the energy value and nutrient content of the diets of households of different composition .sx The averages showed little change compared with those for the previous year , except for generally increased intakes of vitamins C and D. Since physiological requirements vary widely with age , sex and level of activity , comparisons between families of different composition are only apposite when considered in relation to needs .sx 80 .sx Estimates of the adequacy of the diets , assessed by comparison with allowances based on the recommendations of the British Medical Association , are also shown in Table 30 .sx In comparison with the previous year , changes were small except for higher estimates for vitamin C. In families with four or more children the levels of adequacy for all nutrients other than vitamin C decreased slightly .sx For this fairly small group , comparisons between different years cannot be made so precisely as in groups with a defined number of children .sx In 1959 the households in this group contained slightly more children ( average 4.64 ) than in the previous year ( average ) .sx Their total food expenditure increased less than that in other groups , and they purchased more of certain foods such as fish , poultry , eggs , canned vegetables , fresh fruit , chocolate biscuits and breakfast cereals which , in general , are more expensive sources of nutrients than those foods of which they purchased less , namely dried milk , potatoes , carcase meat , sugar , bread , flour and oatmeal and oat products .sx 81 .sx In all these estimates of adequacy , the conventional allowance of 10 per cent has been made for wastage of edible food .sx The limitations of the use of arbitrary wastage factors , regardless of family size or circumstances , were pointed out , and the effect of the use of graduated wastage factors examined in the Annual Report for 1956 .sx As in previous years , the percentages in Table 30 for all nutrients decreased with increasing family size .sx The lowest estimates were for protein and calcium in families with four or more children ( 82 and 81 per cent respectively) .sx During the ten years from 1950 to 1959 there were downward trends in the percentages for protein and calcium for all types of family and for all households , the steepest ( from 94 to 82 per cent for protein and , from 92 to 81 per cent for calcium ) occurring for the families with four or more children ; another considerable fall was from 91 to 83 per cent for protein in families with adolescents and children .sx