Gambian infants show growth faltering, but the underlying body composition is unknown. The present study aimed to compare body composition in Gambian and UK infants using 2H dilution; and to evaluate accuracy of bioelectrical impedance analysis (BIA) and creatinine excretion for estimating lean mass (LM), using 2H as the reference. Body composition was measured in thirty Gambian infants, aged 3–18 months, using (1) anthropometry, (2) 2H, (3) BIA (equation of Fjeld et al.Pediatr Res (1990), 27, 98–102) and (4) 5 h urinary creatinine excretion. Compared with UK reference data, Gambian infants were light, short and had reduced BMI and skinfolds. The subscapular skinfold standard deviation score (SDS) was greater than the triceps SDS (P < 0·01), indicating central fat preservation. Both LM and fat mass were reduced in Gambian infants, with or without adjustment for length. However, whereas the Gambia–UK difference in LM increased with age, that in fat mass decreased. Average creatinine excretion was similar to that expected (95·5 (sd 23·2) % recovery), but LM estimates showed unacceptable error in individuals. BIA using Fjeld's equation overestimated total body water and LM (P < 0·001), hence a new equation was developed, with standard error of 0·47 kg LM. In conclusion, Gambian infants characterised by growth faltering had LM deficits that increased with age. However, adiposity increased with age, and showed indications of a more central distribution than in the reference infants. A new BIA equation for LM prediction is presented; however, creatinine excretion is not recommended for LM estimation in this population.

A longitudinal study of 298 rural Bangladeshi infants found evidence of growth faltering starting at 3 months of age. Anthropometric status declined substantially in the first 2 years of life, with weight-for-height (WHZ) falling from − 0·49 to − 1·75, weight-for-age (WAZ) from − 1·18 to − 2·87 and height-for-age (HAZ) from − 1·00 to − 1·88. Higher concentrations of the acute-phase protein α-1-acid glycoprotein (AGP) and higher gut mucosal damage (as signified by raised lactulose:mannitol (L:M) ratios) were both associated with chronic malnutrition as indicated by poorer HAZ and WAZ scores (P = 0·011 and 0·005 for AGP and 0·039 and 0·019 for L:M ratio, respectively). Higher Hb levels were related to improved z-scores, while elevation of Giardia-specific IgM titre (GSIgM) was associated with poor WAZ and WHZ (P = 0·015 and 0·039, respectively). IgG did not show any significant association with z-scores and the L:M ratio did not correlate with any of the inflammation markers or Giardia infection. The prevalence of geohelminth infections was low (only 4 % in the total study period). However, the level of GSIgM indicated high endemicity of Giardia infection from early in life, although very few cysts were detected from stool samples. These findings suggest that rural Bangladeshi infants are being exposed to high levels of infection with concomitant gut damage and growth faltering.

Whilst it is generally accepted that breast-feeding lowers the likelihood of conception, this relationship is not straightforward and there appears to be a wide variation in the effectiveness of the association between individual mother-infant pairs. Up to about 6 months post-partum breast-feeding probably can be used as a family planning method, with up to 98% effectiveness if behavioural guidelines are adhered to (Consensus, 1988). But beyond this time significant variations appear between different countries, and even different communities within countries, which make any overall recommendation impossible. To understand the reasons for variation in the duration of lactational infecundity it is necessary to understand the mechanisms involved, but knowledge of these processes is still far from complete. There are, nevertheless, enough data to indicate that suckling and maternal milk output are intimately linked with the return of fecundity.

Early childhood growth retardation persists in developing countries despite decades of nutritional interventions. Adequate food is necessary, but not sufficient, to ensure normal growth where there is ubiquitous exposure to infection. Pathways associated with infection, small intestinal mucosal damage and chronic immunostimulation remain largely undemonstrated in countries other than The Gambia. We conducted a longitudinal study of one squatter and one middle-class group (n 86, 3–18 month olds) to assess these relationships in Nepal. Growth, mucosal damage index (MDI; urinary lactose:creatinine ratio adjusted for body weight), morbidity reports, and blood concentrations of albumin, α-1-acid glycoprotein, IgG and Hb, were recorded monthly. Growth status worsened dramatically from 6 to 18 months, with squatters more stunted (height-for-age Z-score (HAZ), P < 0·001) and underweight (weight-for-age Z-score (WAZ), P = 0·009) than middle class. IgG increased with age, was elevated in squatter children, and negatively related to WAZ (P = 0·034). MDI showed significant negative associations with growth performance, explaining 9 and 19 % of height and weight deficits (ΔHAZ, P = 0·004; ΔWAZ, P < 0·001). Unexpectedly, these associations were weaker in squatter children, namely in the group which showed poorer growth, elevated morbidity, greater pathogen exposure (IgG) and higher MDI (P < 0·001). In Nepal, as in The Gambia, children exhibit poor growth, mucosal damage and immunostimulation. The relative impact of pathways associated with infection and undernutrition may, however, differ across socio-economic groups: in poorer children, the impact of mucosal damage and immunostimulation could be masked by nutritional constraints. This has important implications for public health interventions.

Poor growth performance during infancy and early childhood is a frequent fact of life in most developing countries. Work in The Gambia has demonstrated that more than 43 % of observed growth faltering during the first 15 months of life can be explained by the presence of a mucosal enteropathy in the small intestine. Within communities the illness is very common: in the area investigated more than 95 % of infants above 8 months of age were affected, and on average they suffered a growth-limiting enteropathy for more than 75 % of their first year of life. Two mechanisms of weight loss have been defined. First, partial villus atrophy reduces absorption and digestion of lactose and probably other nutrients. Second, and more importantly, damage to the mucosal barrier allows translocation of macromolecules into the mucosa and blood, triggering both local and systemic immune and inflammatory mechanisms. Given the severity of the enteropathy it is not surprising that infants fail to grow at a normal rate. Recent findings suggest that these lesions continue throughout childhood and into adulthood. Thus, a persistence of chronic, local and systemic inflammation throughout childhood may be responsible for continued poor growth during this period. Although the nature of the enteropathy and the mechanisms of growth failure have been defined, the factors involved in the initiation and persistence of the intestinal lesion remain uncertain, making clinical management difficult. More work is clearly required to elucidate these factors and to define interventions to prevent or treat the enteropathy.

Small bowel enteropathy (assessed by the lactulose (L): mannitol (M) permeability test) is a major factor in infant growth faltering and malnutrition in The Gambia. However, little is known about its persistence and nutritional effect beyond 2 years of age. This was addressed by two cross-sectional studies of intestinal permeability and nutritional status in 162 residents, aged 2–60 years, living in three villages in rural Gambia. L:M ratio was found to be highest in the youngest children and although there was a significant improvement with age (P<0·0001), values were always greater than the range found in UK counterparts. M recovery (mean value 5·68 (SE 0·12)%) was at all times between one-third and one-half of expected UK values and showed no improvement with age. Gut barrier function, assessed by L uptake, improved with age (P<0·001) and fell within the UK normal range beyond age 10 years. Both the L:M permeability ratio and L recovery were significantly associated with height-for-age z-scores (r−0·31 and −0·22 respectively, P<0·001), a relationship that persisted throughout childhood and into adulthood. Change in height-for-age z-score beween the two visits was also related to the L:M ratio (r−0·24, P=0·018). The close within-subject correlation of permeability variabilities between the two visits suggests a long-term persistence of enteropathy within individuals. It appears that the small bowel enteropathy previously described in Gambian infants persists through to adulthood. Although the lesion improves with age, the relationship between attained height and L:M permeability raises the possibility that enteropathy may continue to limit growth throughout childhood and puberty.

Previous studies have described high plasma triiodothyronine (T3) concentrations and sympathetic activity in rats fed on low-protein diets. The present investigation examined how the nutritional status of rats fed on a low-protein diet was affected when these hormonal changes were reduced by drug administration. The low-protein diet (LP group) prevented growth, reduced plasma albumin levels, elevated plasma T3 concentration, and increased both the weight of the interscapular brown adipose tissue (BAT) and the activity of BAT cytochrome c oxidase (EC 1.9.3.1). Lowering the plasma T3 concentration (with carbimazole; CA group) elevated the plasma insulin concentration, promoted a small increase in the plasma albumin concentration and caused weight gain in comparison with the LP group. Reduction of sympathetic activity (with α-methyl-p-tyrosine; MT group) promoted a small elevation in plasma albumin concentration accompanied by a diminished T3 concentration, BAT weight, and an increase in fat deposition in relation to LP rats. In a second experiment, simultaneous lowering of the plasma T3 concentration and sympathetic activity (CA/MT group) resulted in weight gain associated with elevated plasma insulin concentration and fat deposition and a marked reduction in BAT cytochrome c oxidase activity. However no change in the hypoalbuminaemia was observed. The results of the present study suggest that in spite of the previously described increase in metabolic rate in rats fed on a diet with low-protein concentration when compared with controls, the mechanisms involved in the control of BAT activity and fat deposition seem to be independent of those which cause liver protein depletion and hypoalbuminaemia.