Associations between breastfeeding duration and adherence to complementary feeding recommendations in Scotland.

We aimed to describe how breastfeeding relates to adherence to complementary feeding (CF) recommendations, diet diversification and feeding skills development and whether sociodemographic factors explain any differences observed. The Scottish Maternal Infant and Nutrition Survey for infants aged 8-12 months collected breastfeeding history, CF practices, diet and sociodemographic data using a self-completion questionnaire. Non-healthful CF practices were starting CF < 6 months, any consumption of sugar-sweetened beverages (SSBs), sweet or salty snacks (treats) or unmodified cow's milk and regular consumption of commercial baby foods. Diet diversification and feeding skills were assessed by amount of self-feeding and number of food groups, meals and snacks eaten daily. Of the 2730 mothers, 20% were solely infant formula fed (IFF) and 48% continued breastfeeding ≥6 months. Compared to IFF babies, mothers who gave any breast milk ≥6 months were more likely to start CF ≥ 6 months compared to those IFF (66% vs. 37%) and less likely to give treats (15% vs. 45%), SSBs (11% vs. 20%) and commercial baby foods (31% vs. 53%). These associations remained highly significant (p < 0.001) even after sociodemographic factor adjustment. Despite starting CF later, infants breastfed ≥6 months ate the same number of food groups and meals as those IFF, were just as likely to self-feed purees and more likely to self-feed finger foods daily (87% vs. 81% p < 0.001). Mothers who breastfeed beyond 6 months adhere more to CF recommendations and start CF later compared to IFF, but their babies eat a similarly diverse diet and have similar feeding skills.

Does planning to mixed feed undermine breastfeeding?

Continued breastfeeding is important for infants' health, but it is unclear whether mixed feeding increases the risk of breastfeeding cessation. We aimed to explore associations of mixed feeding and lactation problems with early cessation of breastfeeding. We analysed data from mothers who completed the Scottish National Maternal and Infant Feeding Survey and had previously breastfed their infants. At age 8-12 weeks, mothers (N = 1974) reported their feeding history and intentions, lactation problems and reasons for giving formula milk. The main outcome measure was cessation of breastfeeding before 6-8 weeks and time to cessation. By 6 weeks, 65% had mixed fed at some point, 32% had ceased breastfeeding, 22% were currently mixed feeding and 46% were exclusively breastfeeding. Lactation problems before 2 weeks were common (65%), and strongly associated with stopping breastfeeding (relative risk [RR]: 3.23, 95% confidence interval [CI]: 2.0-5.3) and with mixed feeding (RR: 3.14, 95% CI: 2.5-4.0). However, even after adjustment for breastfeeding problems mothers who planned to mixed feed (RR: 3.39, 95% CI: 2.4-4.9) and those who introduced formula for practicalities (RR: 3.21, 95% CI: 2.3-4.4) were more likely to stop breastfeeding. These variables also predicted later lactation insufficiency (planned mixed feeding RR: 1.39, 95% CI: 1.0-2.0; formula for practicalities RR: 1.76, 95% CI: 1.3-2.3). Mothers who received specialist lactation support were less likely to cease breastfeeding (RR: 0.63, 95% CI: 0.5-0.9) but nonspecialist input was unrelated to risk of cessation (RR: 1.06, 95% CI: 0.2-4.9). In conclusion, choosing to mix feed an infant is strongly associated with stopping breastfeeding, even in the absence of lactation problems.

How much do preverbal children signal a wish to be fed? Nested case control study comparing weight faltering and healthy infants.

We aimed to 1/develop an observational tool to rate non-verbal cues infants give when being fed 2/test whether these differ between healthy children and those with weight faltering (WF) 3/describe how well these predict whether offered food is eaten. SUBJECTS: and methods: The study used videos of infants eating a standardised meal studied in a case control study nested within the Gateshead Millennium Study (GMS). Infants with weight faltering (WF) were each matched to 2 healthy controls. Half the control videos (N = 28) were used to develop the scale. Food offers were identified and the child's head, eyes, hands, and mouth position/activity rated as signalling a readiness to be fed (engaged), or not (disengaged) as well as whether food was accepted; 5 of these videos were used to assess inter-rater and test-re- test reliability. The scale was then applied to the videos of 28 WF infants (mean age 15.3 months) and 29 remaining controls (mean age 15.8 months) to identify and code all feeding events. RESULTS: test-re-test rates varied from 0.89 for events to 0.74 for head; inter-rater reliability varied from 0.78 for hands to 0.67 for mouth. From 2219 observed interactions, 48% showed at least one engaged element, and 73% at least one disengaged; 67% of interactions resulted in food eaten, with no difference between WF and control. Food was eaten after 73% interactions with any engagement, but also in 62% with disengagement. CONCLUSIONS: Infants were commonly disengaged during meals, but a majority accepted food despite this. Those with weight faltering did not differ compared to healthy controls.

Infancy weight faltering and childhood neurodevelopmental disorders: a general population birth-cohort study.

While it is known that intrauterine growth restriction is associated with later mental disorders, it is still unclear whether similar associations exists for postnatal weight faltering, also known as 'failure to thrive' in infancy. This study examined the potential connection between infancy weight faltering and mental disorders diagnosed in childhood focusing specifically on neurodevelopmental disorders. The Copenhagen Child Cohort (CCC2000) was used to explore weight gain in infancy assessed by community health nurses. Data from the Danish national registries were used to quantify ICD-10 mental disorders diagnosed between birth and 12 years of age, as well as potential child and family confounders. Of 4.476 children with sufficient weight data, 339 (7.3%) children were diagnosed with a mental disorder in childhood. Both any (weight gain < -1SD) and severe infancy weight faltering (weight gain < -2SD) were associated with psychomotor delays, while severe infancy weight faltering was also associated with intellectual impairments. Notably, no significant associations were found between weight faltering and autism spectrum disorders or attention deficit hyperactivity disorders. Weight faltering in infancy may be an early marker of neurodevelopmental delays. This possibility should be considered when assessing infants with slow weight gain, to early identification and treatment of co-occurring neurodevelopmental disorders.

Prevalence and overlap of known undernutrition risk factors in children in Nairobi Kenya.

We aimed to describe the co-occurrence of known risk factors for undernutrition and the prevalence of modifiable risks in wasted, stunted and healthy children. Quota sampling was used to recruit healthy [weight for age Z scores (WAZ) > -2 SD] and undernourished [weight for length (WLZ) or WAZ scores ≤ -2 SD] children aged 6-24 months from seven clinics in low-income areas of Nairobi. Structured interviews were used to identify exposure to socioeconomic, water and hygiene, infant feeding, dietary and behavioural risks (low interest in food, high food refusal and force feeding). We recruited 92 wasted WLZ ≤ -2 SD, 133 stunted (length for age Z scores LAZ ≤ -2 SD) and 172 healthy (LAZ and WLZ > 2SD) children. Nearly all children were exposed to hygiene risks (90%) and low dietary diversity (95%) regardless of nutritional status. Stunted children were more likely to be exposed to socio-economic risks (54% healthy, 64% wasted and 72% stunted; P = 0.001). Compared with healthy children, wasted and stunted children were more likely to be exposed to infant feeding (25% healthy, 40% wasted and 41% stunted; P = 0.02) and behaviour risks (24% healthy, 49% wasted, and 44% stunted; P = 0.004). Overall, wasted and stunted children were twice as likely to be exposed to more than three risks (23% healthy, 48% wasted, and 50% stunted; P = <0.001). They were also more likely to be exposed to more than three modifiable risks (dietary, handwashing and behaviour risks). Wasting and stunting are associated with exposure to multiple risk factors, many of which are potentially modifiable using targeted advice.

Body composition data show that high BMI centiles overdiagnose obesity in children aged under 6 years.

BACKGROUND: Most authorities define childhood overweight/obesity as a BMI exceeding the same high centile cutoff at all ages, but it seems unlikely that true obesity prevalence (excess body fat) is constant throughout childhood. OBJECTIVES: We investigated how fat mass (FM) and lean mass (LM), adjusted for height, relate to BMI and each other across childhood, using a uniquely large database of body composition measures, estimated using gold standard methods. METHODS: Cross-sectional and cohort data were collated from representative samples of healthy children aged 6 wk to 20 y and children attending obesity clinics aged 7-16 y. Body composition was measured by deuterium dilution up to age 4 y, and by either deuterium or the criterion 4-component model from 4 to 20 y. FM and LM were expressed, respectively, as fat mass index (FMI; FM/height2) and lean mass index (LMI; LM/height2). RESULTS: There were 2367 measurements of weight, height, and body composition from 1953 individuals. Before age 6 y, the variability in FMI, LMI, and BMI was much less than after; FMI was low (mainly <8 kg/m2) and FMI and LMI were weakly negatively correlated. From mid-childhood, upper limits for both BMI and FMI rose, but FMI in children with BMI <91st centile still rarely exceeded 8. With increasing age, the correlation of FMI with LMI rose to 0.5-0.7, driven mainly by children with a high FMI also having a high LMI. CONCLUSIONS: Raised fat levels are much less common at younger than older ages, and young children with a high BMI centile have lower FMI than older children with the same BMI centile. Current BMI centile cutoffs thus overdiagnose obesity in younger groups. More stringent cutoffs are required for children aged <6 y, matching the WHO recommendation for 0-5 y.

Development of a Scale to Measure Infant Eating Behaviour Worldwide.

In order to create a short, internationally valid scale to assess eating behaviour (EB) in young children at risk of undernutrition, we refined 15 phrases describing avidity or food refusal (avoidance). In study one, 149 parents matched phrases in English, Urdu, Cantonese, Indonesian or Greek to videos showing avidity and avoidance; 82-100% showed perfect agreement for the avidity phrases and 73-91% for the avoidant phrases. In study two, 575 parents in the UK, Cyprus and Indonesia (healthy) and in Kenya, Pakistan and Guatemala (healthy and undernourished) rated their 6-24 months old children using the same phrases. Internal consistency (Cronbach's α) was high for avidity (0.88) and moderate for avoidance (0.72). The best-performing 11 items were entered into a principal components analysis and the two scales loaded separately onto 2 factors with Eigen values > 1. The avidity score was positively associated with weight (r = 0.15 p = 0.001) and body mass index (BMI) Z scores (r = 0.16 p = 0.001). Both high and low avoidance were associated with lower weight and BMI Z scores. These scales are internationally valid, relate to nutritional status and can be used to inform causes and treatments of undernutrition worldwide.

Wasting and Stunting in Infants and Young Children as Risk Factors for Subsequent Stunting or Mortality: Longitudinal Analysis of Data from Malawi, South Africa, and Pakistan.

BACKGROUND: Few studies have had sufficient longitudinal data to track how different malnourished states relate to mortality at different ages and interrelate over time. OBJECTIVES: This study aims to describe the RRs and proportions of mortality associated with wasting and stunting and the pathways into and out of these nutritional states. METHODS: Longitudinal growth data sets collected for children ages 0-24 months from Malawi, South Africa, and Pakistan were combined (n = 5088). Children were classified as deceased, wasted (weight for height < -2 SD; 1-4%), stunted (length < -2SD; 20-47%), or wasted and stunted (WaSt; 2-5%) at ages 3, 6, 9, 12, 18, and 24 months. Mixed-effects Cox models were used to study the association between nutritional status and mortality. RESULTS: By age 3 months, 20% of children were already stunted, rising to 49% by 24 months, while wasting (4.2% and 2.2% at 3 months, respectively) and WaSt (0.9% and 3.7% at 24 months, respectively) were less common. The HR for mortality in WaSt was 9.5 (95% CI, 5.9-15), but 60% of WaSt-associated mortality occurred at 3-6 months. Wasting or WaSt was associated with 10-23% of deaths beyond 6 months, but in the second year over half of deaths occurred in stunted, nonwasted children. Stunting persisted in 82% of children and wasting persisted in 44%. Wasted children were more likely than nonwasted, nonstunted children to become stunted (RR, 1.93; 95% CI, 1.7-2.2), but 94% of children who progressed to stunting had not been wasted in the prior period. CONCLUSIONS: WaSt greatly increased the risk of death, particularly in very young infants, but more deaths overall were associated with stunting. Most stunting appeared to be either intrauterine in origin or arose in children without prior wasting. Either stunting and wasting represent alternative responses to restricted nutrition, or stunting also has other, nonnutritional causes.

The Biological and Social Determinants of Childhood Obesity: Comparison of 2 Cohorts 50 Years Apart.

OBJECTIVE: To determine whether the same relationships between early-life risk factors and socioeconomic status (SES) with childhood body mass index (BMI) are observed in a modern cohort (2000) compared with a historic cohort (1947). STUDY DESIGN: The relationships between early-life factors and SES with childhood BMI were examined in 2 prospective birth cohorts from the same region, born 50 years apart: 711 children in the 1947 Newcastle Thousand Families Study (NTFS) and 475 from the 2000 Gateshead Millennium Study (GMS). The associations between birth weight, breastfeeding, rapid infancy growth (0-12 months), early-life adversity (0-12 months), and parental SES (birth and childhood) with childhood BMI z-scores and whether overweight/obese (BMI >91st percentile using UK 1990 reference) aged 9 years were examined using linear regression, path analyses, and logistic regression. RESULTS: In the NTFS, the most advantaged children were taller than the least (+0.91 height z-score, P = .001), whereas in GMS they had lower odds of overweight/obese than the least (0.35 [95% CI 0.14-0.86]). Rapid infancy growth was associated with increased BMI z-scores in both cohorts, and with increased likelihood of overweight/obese in GMS. CONCLUSIONS: This study suggests that children exposed to socioeconomic disadvantage or who have rapid infancy growth in modern environments are now at lower risk of growth restriction but greater risk of overweight.

Eating and feeding behaviours in children in low-income areas in Nairobi, Kenya.

Child eating and caregiver feeding behaviours are critical determinants of food intake, but they are poorly characterized in undernourished children. We aimed to describe how appetite, food refusal and force-feeding vary between undernourished and healthy children aged 6-24 months in Nairobi and identify potential variables for use in a child eating behaviour scale for international use. This cross-sectional study was conducted in seven clinics in low-income areas of Nairobi. Healthy and undernourished children were quota sampled to recruit equal numbers of undernourished children (weight for age [WAZ] or weight for length [WLZ] Z scores ≤2SD) and healthy children (WAZ > 2SD). Using a structured interview schedule, questions reflecting child appetite, food refusal and caregiver feeding behaviours were rated using a 5-point scale. Food refusal and force-feeding variables were then combined to form scores and categorized into low, medium and high. In total, 407 child-caregiver pairs, aged median [interquartile range] 9.98 months [8.7 to 14.1], were recruited of whom 55% were undernourished. Undernourished children were less likely to 'love food' (undernourished 78%; healthy 90% p = < 0.001) and more likely to have high food refusal (18% vs. 3.3% p = <0.001), while their caregivers were more likely to use high force-feeding (28% vs. 16% p = 0.03). Undernourished children in low-income areas in Nairobi are harder to feed than healthy children, and force-feeding is used widely. A range of discriminating variables could be used to measure child eating behaviour and assess the impact of interventions.

Does early introduction of solid feeding lead to early cessation of breastfeeding?

Mixed milk feeding increases the likelihood of breastfeeding cessation, but it is not known if solid feeding (SF) has the same effect. We have identified 10,407 infants breastfed for at least 8-10 weeks from three large U.K. studies (Avon Longitudinal Study of Parents and Children [ALSPAC; born 1990-1991], Southampton Woman's Survey [SWS; 1998-2008], and Infant Feeding Survey 2010 [IFS 2010]) to investigate the associations between early SF and breastfeeding cessation. In the earliest study (ALSPAC), 67% had started SF before the age of 4 months, but in the latest (IFS), only 23% had started before 4 months. Solid food introduction before 4 months was associated with stopping breastfeeding before 6 months in all three cohorts, with little effect of adjustment for maternal sociodemographic characteristics (Poisson regression, adjusted prevalence ratios: ALSPAC 1.55, [95% confidence interval 1.4, 1.8], SWS 1.13 [1.0, 1.3], IFS 1.10 [1.1, 1.3]). Using Cox regression, adjusted hazard ratios for breastfeeding cessation compared with SF after 5 months were 2.07 (1.8, 2.4) for SF before 4 and 1.51 (1.3, 1.8) at 4-5 months for ALSPAC and 1.25 (1.1, 1.5) and 1.15 (1.0, 1.3) for SWS. Earlier introduction of solids was associated with a shorter duration of breastfeeding, particularly in cohorts where earlier introduction of solids was the norm, with a dose-response relationship, which was not explained by background social characteristics. As mothers most commonly introduced solids in the month prior to the then recommended age, continuing to recommend deferring solids to the age of 6 months is important to support sustained breastfeeding.

What Can Meal Observations Tell Us about Eating Behavior in Malnourished Children?

Responsive feeding is an important aspect of child care, yet little is known about child eating and caregiver feeding behavior in Kenya. This study aimed to develop a mealtime observation methodology and assess child eating and caregiver feeding behavior in healthy and undernourished children in Nairobi. Healthy (n = 6) and undernourished (n = 13) children aged 6-24 months were observed during a meal, with standardized rating of child interest in food, mood, distraction and caregiver responsiveness. Eating and feeding behavior varied with the stage of the meal. Child interest in food decreased and child and caregiver distraction increased as the meal progressed. Healthy children were happy and interested in food during meals, but undernourished children often had low interest in food (7/13). The 7 undernourished children eating home food were distracted (3) and unhappy (5) but children eating ready-to-use therapeutic foods (6) were all happy and undistracted. Caregivers of healthy children offered encouragement more often during meals than caregivers of undernourished children (5/6 healthy, 3/13 undernourished). Meal observations were resource intensive and could give only a snapshot of the child feeding experience. More efficient research methods that can capture a general assessment of infant eating behavior are needed.

Assessing the Potential for Integrating Routine Data Collection on Complementary Feeding to Child Health Visits: A Mixed-Methods Study.

There is no routine data collection in the UK on infant dietary diversity during the transition to solid foods, and health visitors (HVs) (nurses or midwives with specialist training in children and family health) have the potential to play a key role in nutrition surveillance. We aimed to assess items for inclusion in routine data collection, their suitability for collecting informative data, and acceptability among HVs. A mixed-methods study was undertaken using: (i) an online survey testing potential questionnaire items among parents/caregivers, (ii) questionnaire redevelopment in collaboration with community staff, and (iii) a survey pilot by HVs followed by qualitative data collection. Preliminary online questionnaires (n = 122) were collected to identify useful items on dietary diversity. Items on repeated exposure to foods, aversive feeding behaviors, flavor categories, and sugar intake were selected to correspond to nutrition recommendations, and be compatible with electronic records via tablet. HVs surveyed 187 parents of infants aged 12 months. Semi-structured interviews indicated that HVs found the questionnaire comparable with standard nutrition conversations, which prompted helpful discussions, but questions on eating behavior did not prompt such useful discussions and, in some cases, caused confusion about what was 'normal.' Lack of time among HVs, internet connectivity issues, and fear of losing rapport with parents were barriers to completing electronic questionnaires, with 91% submitted by paper. Routine nutrition data collection via child health records seems feasible and could inform quality improvement projects.

Prevalence of under and over weight in children with neurodisability, using body composition measures.

We aimed to compare rates of under and overweight in children with different neurodevelopmental disorders (NDD) by measuring weight, height/length, arm-to-leg bioelectrical impedance (BIA) and subscapular and triceps skinfolds in 146 children aged 4-16 years attending special schools. Z scores were calculated and skinfolds and lean mass Z scores were further adjusted for height. Underweight was found in 9% (14) children (body mass index (BMI) < 2nd) but only 3% (4) had skinfolds <5th centile. Overweight was much commoner, with 41% (58) children having BMI > 95th and 20% (14) had skinfolds >95th centile. Children with cerebral palsy were very short with low BMI and lean mass, but only 8% (3) had skinfolds <5th centile. The children with Down syndrome were also very short and once adjusted for height, half had skinfolds >95th centile. We conclude that overweight and raised body fat is now common in children with NDD, even when the BMI is low.

Uses and abuses of snack foods in child health.

Snack foods, though regarded as unhealthy, are widely eaten by children, particularly those with eating and feeding difficulties. This article outlines the ways in which paediatricians have traditionally made use of snack foods as incentives and then reviews the key nutritional and practical characteristics of commonly eaten snack foods, to allow practitioners to evaluate their role in the child's diet. Generally savoury snacks are preferable to sweet, while dry foods are preferable to drinks or semiliquid desserts. Many ostensibly healthy snacks are also rich in sugar or fat. Eaten in addition to other meals, snack foods may lead to obesity or else displace family foods, but the instant appeal of snack foods can be exploited to introduce young children to otherwise aversive sensations and tastes and can prove a useful path towards a more diverse future diet. If a reasonable variety of snack foods are taken, this will still form a fairly balanced, if non-ideal, diet.

Validation of US cerebral palsy growth charts using a UK cohort.

AIM: Growth charts for cerebral palsy (CP) have been constructed using data for 24 920 Californian patients, covering ages 2 to 20 years, with separate charts for the five severity levels of the Gross Motor Function Classification System (GMFCS). Our aim was to test how the data for British children with CP fit these charts, compared with conventional local charts. METHOD: US CP growth reference was reanalysed using the lambda-mu-sigma (LMS) method to allow calculation of standard deviation z-scores. Growth data for 195 children with CP in Glasgow, UK, were retrieved and converted to z-scores using the CP reference as well as the combined World Health Organization and UK 1990 growth reference (UK-WHO). RESULTS: Compared to the UK-WHO reference, measurements diverged progressively with increasing severity, with mean height for GMFCS level V being close to the second UK-WHO centile. Compared with the CP reference, mean height and weight z-scores were between the 50th and 75th centiles for all severity levels, while body mass index was just below the 50th centile. INTERPRETATION: British children with severe CP seem relatively very small when their growth data are plotted on non-CP charts, but their data for weight and body mass index fit well to US CP charts and reasonably well for height. The LMS look-up tables will make it possible to calculate z-scores and produce charts in local formats.

Does measurement technique explain the mismatch between European head size and WHO charts?

OBJECTIVE: To test whether different measuring techniques produce systematic differences in head size that could explain the large head circumferences found in Northern European children compared with the WHO standard. DESIGN: Cross-sectional observational study. SETTING: Scotland, UK. PATIENTS: Study 1: 68 healthy children aged 0.4-18 months from mother and baby groups and a medical students teaching session. Study 2: 81 children aged 0.4 to 25 months from hospital wards and neonatal follow-up clinics. INTERVENTIONS: Study 1: heads measured with plastic tape using both the WHO tight and UK loose technique. Study 2: heads measured using WHO research technique and a metal measuring tape and compared with routinely acquired measurements. MAIN OUTCOME MEASURES: Mean difference in head z-scores using WHO standard between the two methods. RESULTS: The tight technique resulted in a mean (95% CI) z-score difference of 0.41 (0.27 to 0.54, p<0.001) in study 1 and 0.44 (0.36 to 0.53, p<0.001) in study 2. However, the mean WHO measurements in the healthy infants still produced a mean z-score that was two-third of a centile space (0.54 SD (0.28 to 0.79) p<0.001) above the 50th centile. CONCLUSION: The WHO measurement techniques produced significantly lower measures of head size, but average healthy Scottish children still had larger heads than the WHO standard using this method.

Health staff understanding, application, and interpretation of growth charts in Nigeria.

We aimed to compare plotting accuracy and interpretation of weight gain patterns in average and small infants on road-to-health (RTH) and the new World Health Organization (WHO) growth charts in Enugu, Nigeria. Child health staff plotted standard weights on both formats. Twelve plotted charts were created, permutating three different weight trajectories (fast, steady, and slow) ending at two attained weights (average and small), with each plotted on both chart formats. Respondents were shown four of these charts and asked to describe the weight gain pattern shown and what action this pattern would prompt. There were 222 respondents, of whom 78% were hospital based; 54% were nurses, 32% medical doctors, and 13% nutritionists. Plotting accuracy was good on both the WHO and RTH charts, but rating of weight gain was generally poor. On the RTH chart, slow weight gain was correctly recognized in only 19% average and 35% small infants, and responses were not significantly associated with the pattern shown. On the WHO charts, slow weight gain was correctly recognized in 40% average and 65% small infants (p = .002 and <.001), but they were also more likely to rate small children with normal growth as slow weight gain. In a logistic regression model, final weight predicted a slow weight gain rating more strongly (OR = 2.4; 1.8-3.2) than an actual slow weight gain pattern (OR 1.8; 1.1-1.6). Health staff seemed unable to recognize slow weight gain and were influenced more by current weight than actual weight gain pattern, though the new WHO format improved recognition.

Assessment of adult body composition using bioelectrical impedance: comparison of researcher calculated to machine outputted values.

OBJECTIVES: To explore the usefulness of Bioelectrical Impedance Analysis (BIA) for general use by identifying best-evidenced formulae to calculate lean and fat mass, comparing these to historical gold standard data and comparing these results with machine-generated output. In addition, we explored how to best to adjust lean and fat estimates for height and how these overlapped with body mass index (BMI). DESIGN: Cross-sectional observational study within population representative cohort study. SETTING: Urban community, North East England PARTICIPANTS: Sample of 506 mothers of children aged 7-8 years, mean age 36.3 years. METHODS: Participants were measured at a home visit using a portable height measure and leg-to-leg BIA machine (Tanita TBF-300MA). MEASURES: Height, weight, bioelectrical impedance (BIA). OUTCOME MEASURES: Lean and fat mass calculated using best-evidenced published formulae as well as machine-calculated lean and fat mass data. RESULTS: Estimates of lean mass were similar to historical results using gold standard methods. When compared with the machine-generated values, there were wide limits of agreement for fat mass and a large relative bias for lean that varied with size. Lean and fat residuals adjusted for height differed little from indices of lean (or fat)/height(2). Of 112 women with BMI >30 kg/m(2), 100 (91%) also had high fat, but of the 16 with low BMI (<19 kg/m(2)) only 5 (31%) also had low fat. CONCLUSIONS: Lean and fat mass calculated from BIA using published formulae produces plausible values and demonstrate good concordance between high BMI and high fat, but these differ substantially from the machine-generated values. Bioelectrical impedance can supply a robust and useful field measure of body composition, so long as the machine-generated output is not used.