A critical analysis of measured food energy intakes during infancy and early childhood in comparison with current international recommendations

An examination of published reports of measured energy intakes of infants and young children reveals that during the first year of life the pattern of change in food energy intake differs fundamentally from the WHO/FAO (1973) Recommendations. In contrast to the progressive linear decline in intake per kg body weight that has previously been assumed, measured intakes are not only substantially lower, but fall much more rapidly up to six months. In even greater contrast, they then rise again, to coincide with the recommendations, reaching a peak at around two years. These findings enable a more realistic assessment to be made of the adequacy of breast milk as the sole source of food in the early months of life.

Riboflavin status in Gambian pregnant and lactating women and its implications for Recommended Dietary Allowances

Riboflavin status by the erythrocyte glutathione reductase (NAD(P)H2:glutathione oxidoreductase EC1.6.4.2) test, and dietary riboflavin intake, were measured in 156 pregnant and lactating women in Keneba, a rural Gambian village, and in 59 pregnant and lactating women in Cambridge, England. The Keneba women were studied longitudinally, for up to 19 months. In Keneba, where the mean daily riboflavin intake was 0.5 mg, the mean erythrocyte glutathione reductase activation coefficient was 1.78 and there was a marked deterioration of biochemical status near parturition. In Cambridge, where the mean intake was 2.3 mg/day, the mean activation coefficient was 1.19. A vitamin fortified diet supplement, given to lactating women in Keneba for 8 months, raised their mean riboflavin intake for 0.5 to 1.5 mg/day and reduced the mean activation coefficient to 1.42. It is therefore likely that an intake even greater than the current United Kingdom or United States recommended daily amounts would be needed to achieve biochemical 'normality' in these women.

Folate status and its relation to vitamin C in healthy elderly men and women

Plasma and red-cell folate levels and dietary folate intake were monitored for about six months, including two months during which supplementary vitamin C was given, in 21 healthy elderly men and women living at home in the north of England. Although biochemical values were consistently low in some subjects, no clinical folate deficiency was detected. Dietary folate intake was significantly correlated with red-cell folate, but not with plasma folate. Before vitamin C supplementation, folate intake was significantly correlated with vitamin C intake, and plasma, but not red-cell, folate was significantly related to plasma and buffy-coat vitamin C levels. During the period of vitamin C supplementation, no significant changes in plasma or red-cell folate levels were detected, even in subjects who had low initial levels of circulating vitamin C.

Dietary supplementation of Gambian nursing mothers and lactational performance

A dietary supplement, resulting in a mean net increase in energy intake of over 700 kcal/day, was supplied to all nursing mothers in a West African village for 12 months. The supplement produced a slight initial improvement in maternal body weight and subcutaneous fat stores but did not increase breast-milk output or fat content.

The nutrient composition of some cooked dishes eaten in Britain: a supplementary food composition table

The nutrient content of 85 cooked dishes has been calculated using McCance and Widdowson's 'The composition of foods' (Paul & Southgate, 1978). The nutrients covered were energy, fat, protein, carbohydrates, ten minerals and 12 vitamins. Recipes for each dish and the factors used to estimate losses of water in cooking are included.

Relative contributions of diet and sunlight to vitamin D state in the elderly

In winter the vitamin D state of elderly people may reach levels associated with osteomalacia, although the disease may not be clinically apparent. A statistical correlation was observed in a group of elderly subjects during the winter between dietary vitamin D intake and vitamin D state, but the intake was generally too low to make a biologically important contribution to maintaining vitamin D concentrations. Ultraviolet light (UVL) is the primary determinant of vitamin D state in summer and winter, in winter owing to the pools of vitamin D built up during the previous summer. Plasma concentrations of 25-hydroxy vitamin D (25-OHD) in winter of 15.0-22.5 nmol/l (6-9 ng/ml) require that the concentration in the previous summer was over 40 nmol/l (16 ng/ml). To maintain plasma concentrations in the elderly above those associated with osteomalacia a mean dietary vitamin D intake of over 5 microgram/day is required. A more physiological approach, however, would be to increase exposure to UVL.

Long-term vitamin status and dietary intake of healthy elderly subjects. 2. Vitamin C

1. Long-term clinical and biochemical vitamin C (ascorbic acid and dehydroascorbic acid) status and dietary intake of vitamin C were monitored for 18 months in twenty-three relatively-healthy elderly subjects living at home in the north of England.

2. Plasma vitamin C showed a strong positive correlation with buffy-coat vitamin C both cross-sectionally between subjects and longitudinally within subjects; plasma levels, therefore, were almost as good an index of long-term status as buffy-coat levels.

3. Vitamin C intake was strongly correlated with plasma and with buffy-coat levels both between subjects and within subjects. This contrasts with the poor correlation observed between riboflavin intake and biochemical riboflavin status in the same subjects.

4. Subjects with relatively high average intakes showed considerable seasonal variation, and several widely-spaced measurements would be needed to characterize their long-term status accurately. Those with low average intakes and blood levels showed little variation during the study.

5. The strongest within-subject correlation was obtained by relating the biochemical values to the 7 d dietary intake directly preceding the biochemical analysis. Blood and tissue levels therefore appear to be strongly related to the current dietary intake.

6. Although some subjects had blood vitamin C levels consistently within the region associated with biochemical deficiency, none showed clinical evidence of specific deficiency symptoms.

7. After the main study, fifteen of the subjects received supplementary vitamin C for 2 months. Plasma and buffy-coat levels rose sharphy, but fell to presupplementation levels within 1 month of withdrawal, emphasizing the transitory nature of increased tissue levels. No significant changes were detected in the following collagen-related urinary ratios: hydroxyproline: creatinine, proline: creatinine, proline: total amino-nitrogen and proline: hydroxyproline in hydrolysates either of whole urine or of various fractions. These variables thus appear to be insensitive to short-term changes in vitamin C status over the ranges encountered in this study.

Long-term vitamin status and dietary intake of healthy elderly subjects. 1. Riboflavin

1. Long-term clinical and biochemical riboflavin status and dietary intake of riboflavin were monitored for 18 months in a group of twenty-three relatively-healthy elderly subjects living at home in the north of England. 2. Both dietary intake and biochemical status, as measured by the activation coefficient (stimulated:basal activity) of NAD(P)H2:glutathione oxidoreductase (EC 1.6.4.2), remained fairly constant for each individual and for most subjects the usual intake and biochemical status were characterized quite accurately by a single week's intake dietary record and a single measurement of the activation coefficient. 3. The expected relationship between biochemical status and dietary intake was present, but not strongly evident. There was a significant within-subject correlation between alpha values and the immediately preceding dietary intake; however the between-subject correlation between alpha values and dietary intake approached zero if the two subjects receiving long-term riboflavin supplements were omitted. Over the limited range of intakes observed in unsupplemented subjects, non-dietary factors evidently obscure the relationship. 4. Although eight subjects had average values above 1.2 for the activation coefficient, no excessively high values were observed, and no subject showed any clear-cut clinical deficiency symptoms.

The quantitative effects of maternal dietary energy intake on pregnancy and lactation in rural Gambian women

The quantitative relationships between dietary energy intake and weight gain in pregnancy, birthweight and lactation performance during the first three months of infancy have been studied in such a way as to take account of major differences in the patterns of heavy manual labour at different times of the year in a subsistence farming community. Maternal weight gain and the accumulation of subcutaneous fat were significantly lower when the last trimester of pregnancy fell during the time of heaviest farm work and lowest energy intakes. The birth-weight of babies was also significantly correlated with differences in energy intake throughout the year. During early lactation breast milk yields were significantly related to concomitant alterations in the subcutaneous fat stores. Evidence has been produced which suggests that in undernourished nursing women there could be a competition for dietary energy between the repleting maternal subcutaneous fat organs and the mammary glands at the expense of milk production.

Free sugars in foods

The values for the free sugars analysed in the samples collected for the fourth edition of McCance and Widdowson's 'The composition of foods' have been combined with values from the literature to provide some basic information on the distribution of free sugars in a range of foods.