Mothers' judgements about their child's weight: distinguishing facts from values.

BACKGROUND: Mothers' responses to questionnaire items assessing their child's weight status typically do not correspond to conventional clinical classifications based on body mass index (BMI). From this observation health professionals infer that mothers do not recognize overweight in their child. But the questions used have generally confounded factual judgements with values, so it is not clear whether the mothers are making factual errors, or differ from professionals in their values. METHODS: Cross-sectional study of population-based birth cohort at 6-8 years and their mothers (n = 540). An objective BMI matching task was used to determine the accuracy of mothers' recognition of their child's weight. Mothers matched their child to sex- and age-specific images of children of known BMI ranging from very thin to obese, and chose a descriptor of their child's weight of the kind used in previous research. RESULTS: Mothers tended to underestimate their child's BMI on the matching task. Matching errors significantly predicted mothers' description of their child's weight; those who overestimated their child's BMI on the matching task were more likely to say their child was overweight, while those who underestimated it were less likely to, independently of their child's actual BMI. CONCLUSIONS: Educational programmes aimed at parents of young primary school children need to address separately the factual and the evaluative components of their assessment of child weight.

When do mothers think their child is overweight?

OBJECTIVE: To quantify how overweight children have to be for their mothers to classify them as overweight and to express concern about future overweight, and to investigate the adiposity cues in children that mothers respond to. DESIGN: Cross-sectional. SUBJECTS: A total of 531 children from the Gateshead Millennium Study cohort at 6-8 years and their mothers. MEASUREMENTS: In the mother: responses to two questions concerning the child's adiposity; height; weight; educational qualifications; and economic status. In the child: height; weight; waist circumference; skinfold thicknesses; bioelectrical impedance; and bone frame measurements. RESULTS: The body mass index (BMI) at which half the mothers classify their child as overweight was 21.3 (in the obese range for children of this age). The BMI at which half the mothers were concerned about their child becoming overweight in the future was 17.1 (below the overweight range). Waist circumference and skinfolds contributed most to mothers' responses. Although BMI and fat scores were important predictors individually, they did not contribute independently once waist circumference and skinfolds (their most visible manifestations) were included in the regression equations. Mothers were less likely to classify girls as overweight. Mothers with higher BMIs were less likely to classify their child as overweight, but were more likely to be concerned about future overweight. CONCLUSION: Health promotion efforts directed at parents of young primary school children might better capitalise on their concern about future overweight in their child than on current weight status, and focus on mothers' response to more visible characteristics than the BMI.

Parental perceptions of weight status in children: the Gateshead Millennium Study.

OBJECTIVES: To investigate parents' perceptions of weight status in children and to explore parental understanding of and attitudes to childhood overweight. DESIGN: Questionnaires and focus groups within a longitudinal study. SUBJECTS: 536 parents of Gateshead Millennium Study children, of which 27 attended six focus groups. MAIN OUTCOME MEASURES: Parents' perception of their child's weight status according to actual weight status as defined by International Obesity Taskforce (IOTF) cutoffs. Focus group outcomes included parental awareness of childhood overweight nationally and parental approaches to identifying overweight children. RESULTS: The sensitivity of parents recognising if their child was overweight was 0.31. Prevalence of child overweight was underestimated: 7.3% of children were perceived as 'overweight' or 'very overweight' by their parents, 23.7% were identified as overweight or obese using IOTF criteria. 69.3% of parents of overweight or obese children identified their child as being of 'normal' weight. During focus groups parents demonstrated an awareness of childhood overweight being a problem nationally but their understanding of how it is defined was limited. Parents used alternative approaches to objective measures when identifying overweight in children such as visual assessments and comparisons with other children. Such approaches relied heavily on extreme and exceptional cases as a reference point. The apparent lack of relevance of childhood overweight to their child's school or own community along with scepticism towards both media messages and clinical measures commonly emerged as grounds for failing to engage with the issue at a personal level. CONCLUSION: Parents' ability to identify when their child was overweight according to standard criteria was limited. Parents did not understand, use or trust clinical measures and used alternative approaches primarily reliant on extreme cases. Such approaches underpinned their reasoning for remaining detached from the issue. This study highlights the need to identify methods of improving parental recognition of and engagement with the problem of childhood overweight.

Testosterone reduces refractory period of stria terminalis neurons in the rat brain.

The absolute refractory period of neurons projecting from the corticomedial amygdala to the medial preoptic-anterior hypothalamic junction in rats was significantly increased by castration (from 1.01 to 1.61 milliseconds) and decreased again by testosterone (from 1.48 to 0.97 millisecond). Corticomedial amygdala neurons which projected to the capsule of the ventromedial nucleus of the hypothalamus were unaffected. These results demonstrate a specific, direct neuronal effect of testosterone.

Low cord ghrelin levels in term infants are associated with slow weight gain over the first 3 months of life.

Lower ghrelin levels have been related to slower growth in small for gestational age infants, and infants with higher cord leptin levels have been reported to gain weight more slowly from birth to 2 yr. This study investigated whether cord blood ghrelin and leptin levels are related to weight gain up to 12 wk of age. One hundred infants were weighed at birth and at 12 wk, and cord blood was assayed for ghrelin and leptin. The mean (+/-sd) birth weight was 3.458 (0.433) kg (median, 3.390; range, 2.510-4.615 kg). The mean (+/-sd) leptin level was 10.1 (6.7) ng/ml (median, 8.4; range, 1.6-36.7 ng/ml), and that of ghrelin was 760.9 (282.9) pg/ml (median, 770; range, 210-1670 pg/ml). Higher birth weight was associated with slower weight gain. Leptin was correlated with birth weight, but ghrelin was not, and leptin and ghrelin levels were not significantly correlated with one another. With birth weight as a control variable, ghrelin was significantly associated with slow weight gain (chi(2) = 7.20 with 1 df; P < 0.01), although leptin was not (chi(2) = 1.59 with 1 df; P > 0.1). In conclusion, lower cord ghrelin levels are associated with slower weight gain from birth to 3 months of age.

Effect of testosterone on neuronal refractory periods, sexual behaviour and luteinizing hormone: a comparison of time-courses.

Measurements of the refractory period of stria terminalis neurones that are sensitive to testosterone propionate, of sexual behaviour and of plasma levels of LH were taken in castrated rats at various times after initiation of treatment with testosterone propionate. Levels of LH dropped within 24 h, before there was any change in neuronal refractory periods. The period of latency to mounting, however, was reduced to its shortest only after 7-8 days and ejaculations first occurred at the same time; these sexual responses correlated in time with reduction of the neuronal refractory period to its lowest level.

Family, socioeconomic and prenatal factors associated with failure to thrive in the Avon Longitudinal Study of Parents and Children (ALSPAC).

BACKGROUND: The epidemiological profile of infants failing to thrive is unclear. The aim of this study is to investigate the prenatal and socioeconomic factors associated with these infants using standardized weight gain conditional on previous weight. METHODS: In a large UK population cohort study, 11 718 infants born at term in 1991-1992 with no major congenital abnormalities were identified. Using a weight gain criterion conditional on initial weight from birth to 6-8 weeks, 6-8 weeks to 9 months, and birth to 9 months, the slowest gaining 5% were identified. RESULTS: None of the prenatal factors was associated with failure to thrive in the multivariable analysis nor were traditional markers of socioeconomic deprivation such as poor parental education or low occupational status. Parental height was significantly correlated with slow infant weight gain in both separate periods and from birth to 9 months (Pearson's r = +0.20, P < 0.001). Eight times as many infants born to shorter parents (8.7%, 95% CI: 6.6, 11.3) showed slow weight gain as infants born to taller parents (1.1%, 95% CI: 0.5, 2.5). Higher parity was also related to slow infant weight gain; infants born in the fourth or subsequent pregnancy were twice as likely to fail to thrive from birth to 9 months (8.3%, 95% CI: 6.4, 10.6) as first-born infants (3.4%, 95% CI: 2.9, 10.6). CONCLUSIONS: Future studies need to take account of parental height when calculating growth standards and look at why failure to thrive is more common, not in poorer families but in larger families.

Pattern of sucking in the infant rat during spontaneous milk ejection.

Two methods are described for measuring the sucking of rat pups on the nipples of the mother. The first uses pressure recording of the cannulated teatduct; the second uses direct observation of sucking behavior. Using these methods, the sucking behavior of the pups during sequences of milk ejections was investigated. Pressure recordings of the sucking of individual pups on the nipple showed that between milk ejections the pups sucked intermittently in bursts. During milk ejection itself there was a longer period of vigorous and continuous sucking. Behavioral observations on the level of sucking in whole litters of pups showed that the background bursts of sucking from the litter as a whole were randomly distributed in relation to the inferred time of oxytocin release. These results indicate that once the pups are sucking on the nipples, variations in the sucking behavior of the litter have no role in the timing of milk ejections in the mother.

The sexual attractiveness of male rats: olfactory and behavioral components.

Female rats are more attracted to intact than to castrated males. In this study, we compared the approach of female rats, in a straight runway, to (1) castrated males, which neither smell nor behave like intact males, (2) castrated males treated with dihydrotestosterone (DHT), which smell like intact males but behave like castrate males, and (3) castrated males treated with DHT and estradiol benzoate (EB), which both smell and behave like intact males. It was found that females ran faster to DHT males than to the castrate controls; and faster to the DHT-EB group than to the DHT group. Thus the odour and the sexual activity of male rats are independent effective sources of incentive to females.

Gonadal hormones and effects of partial reinforcement on appetitive behaviour in the rat.

Two experiments are reported in which rats were run in the straight alley with partial (PR) or continuous (CR) food reinforcement during acquisition and then extinguished. Hormone treatment (with estradiol benzoate, EB, or testosterone propionate, TP) was given during acquisition on both CR and PR schedules, but not during extinction. The results showed no effect of EB on the partial reinforcement extinction effect (PREE) in female rats. In males TP was found to reduce the PREE by differentially reducing resistance to extinction in the PR condition. Thus TP but not EB attenuates the behavioural effects of nonreward.

Infant weight in relation to nutritional intake and morbidity in northern Thailand.

A cross-sectional study of 58 infants (age range 2-53 weeks) was carried out in a rural area of northern Thailand. Total dietary intake (energy and protein from breastmilk and supplementary food) was measured directly during continuous observation over 48 h of randomly selected study subjects in their homes. Associations between infant weight and total energy intake, total protein intake and morbidity were analysed by multiple regression analysis. Up to 6 months of age, heavier infants had larger energy intakes, when age and birthweight were taken into account. In the 7-12 months age group, heavier infants consumed more protein and had fewer respiratory infections. Weaned infants older than 6 months were significantly heavier and consumed more protein than infants of similar age who were still receiving breastmilk. The lower protein intakes of the latter infants were due to the low protein concentration of breastmilk compared with supplementary food.

Sucking patterns of human babies on the breast.

Twenty-seven 5--8-day-old babies were filmed during normal breast feeding (one feed each). Sucking patterns were determined from the film from a total sample of 17,676 sucks. Intersuck interals fell on two distributions: one of intervals between sucks during bursts of sucking (1.3 sec and less), and the other of rests between bursts of sucking (1.3 to greater than 12 sec). As the milk flow dropped towards the end of the feed on each breast, the sucking rate within bursts increased (P less than 0.05), but there were more (P less than 0.001) and longer (P less than 0.001) rests between bursts of sucking. This study provides normative data on a normal population for use in studies of breast feeding.

Energy intake, appetite and body mass in infancy.

Energy intake in infancy depends on the infant's appetite, which, in turn, depends to a considerable extent on the infant's size, as size is an important determinant of energy expenditure. Previous work on six-week old breast-fed infants has suggested that, at this age, milk intake in infants is proportional to the square root of body weight (wt.(0.5)). In this paper, the form of the relationship between body weight and energy intake is examined in infants of different ages, using data from two longitudinal studies, one of initially breast-fed and one of initially bottle-fed infants. In the first data set, energy intake is proportional to body weight raised to powers ranging from 0.63 to 1.23 at different ages and, in the second, to body weight raised to powers ranging from 0.50 to 1.07 at different ages. No single value is consistent with all the data at all ages. In general, the powers decrease up to six months of age, and then increase again, a pattern that may be due to the pattern of changes in the adiposity of the infants, as reflected in their body mass indexes (BMIs).

Effect of a traditional and of a new nipple shield on sucking patterns and milk flow.

The effect of a traditional (Mexican Hat) and of a new (Thin Latex) nipple shield on the sucking patterns and milk intake of 5-8-day-old babies was examined. Milk intake was determined accurately by test weighing using a Sartorius electronic balance with animal weighing keyboard, and sucking patterns by filming the mouth of the baby. The Mexican Hat reduced milk transfer by 58% (P is less than 0.01), and increased sucking rate (P is less than 0.05) and time spent resting (P is less than 0.01). The Thin Latex nipple shield reduced milk intake by a smaller amount (22%), and had no significant effect on sucking patterns.

Individual patterns of milk intake during breast-feeding.

The pattern of milk transfer during breast-feeding was ascertained for individual mother-infant pairs using a 'fractional' weighing technique. This method employs a single, fixed intermediate weighing on each breast, and a flexible, final weighing point at the 'natural' termination of feeding on each breast. The data demonstrate considerable variability between individuals both in feed length and in the rate of milk transfer from mother to baby. They show that the rate of intake tends to be consistent between the first and second breast, and that each mother-infant pair has a characteristic rate of milk transfer. Significant milk intake occurred from four minutes to the end of the feed on each breast. These results imply that breast-feeding 'rules' about the length of a feed can only be offered as helpful guidelines, rather than principles to be strictly followed. The results of a reciprocal nursing experiment suggest that the typical rate of milk transfer is a product of both milk release by the mother and milk demand by the baby.

The continuous measurement of milk intake at a feed in breast-fed babies.

A method for the continuous measurement of milk intake during a breast-feed is described. A miniature Doppler ultrasound flow transducer, located in the tip of a latex nipple shield, is interposed between mother and baby during feeding. Preliminary results indicate the scope and current limitations of the method in terms of both populations and individual mother/infant pairs. An initial analysis of individual feeds indicates that two factors may contribute to the curtailment of intake during a feed from one breast: a progressive reduction in intake volume per suck, and/or an increase in the proportion of time spent pausing between bursts of sucking.

Evaluating breast-milk intake by test weighing: a portable electronic balance suitable for community and field studies.

A K-Tron Digital Scale (Model DS-1) was used to weigh a group of 52 new born babies. The regression of the weights on true weights obtained with a Sartorius electronic balance 3806MP was 0.9911, with an estimated residual variance of 5.25. With the same babies weighed on a Marsden Weighmaster, the estimated residual variance was 68.93. Data from published studies on other balances are presented for comparison. The K-Tron is a reliable, portable, battery operated balance suitable for measuring milk intake by test weighing in homes or in the field.

Relationships between nursing patterns, supplementary food intake and breast-milk intake in a rural Thai population.

Relationships between nursing patterns, supplementary food intake and breast-milk intake were examined in a group of 52 Thai babies under 1 year of age. All data were collected over two consecutive days, 24 h/day. Total sucking time (min/day) and supplementary food intake (kcal/day) were significant predictors of breast-milk intake after allowing for the age of the baby: R-squared is 0.32 for sucking time and 0.39 for supplementary food intake. The two variables were themselves correlated (r is -0.47). The number of breastfeeds per day and their mean duration was determined for each case, counting each episode of attachment to the breast as a separate feed. Number and mean duration of breastfeeds were then evaluated as predictor variables. The duration of feeds had no predictive power. Number of feeds was linearly related to milk intake and combined with age was as good a predictor of milk intake as total sucking time (with R-squared 0.34). These results suggest that a simple count of breastfeeds is as valuable as more complex measures of sucking duration in predicting to breast-milk intake.

Effects of parity on breastfeeding: a study in the rural setting in northern Thailand.

UNLABELLED: This analysis was undertaken to see whether or not previous successful breastfeeding has any influence on subsequent breastfeeding behavior. Lactational outcomes were compared between those with and without breastfeeding experience. METHODS: Amount of breast milk transferred, frequency of breastfeeding, and time spent on the breast, as well as infant's weight, were recorded on days 15, 45, 90, 180, 270, and 360 postpartum in 30 primiparae and 30 multiparae. Outcomes of the primiparae were found to be similar to those of the more experienced breastfeeding multiparous mothers with respect to infant growth, amount of breast milk transferred, and the frequency of breastfeeding or number of attachments to the breast. Though primiparae took somewhat longer to transfer similar amounts of breast milk to their infants during the initial 45 to 90 days postpartum, feed duration after 90 days was similar to that of the multiparae. Lactation performance of the rural northern Thai mothers in our sample was highly successful with or without previous breastfeeding experience. It may be that a cultural pattern of breastfeeding on demand, strong family support, and traditional practices that encourage close contact between mother and her newborn compensate for the absence of lactational experience. Unlike reports from Western countries, previous breastfeeding does not appear to be an important predictor of successful and prolonged breastfeeding in our population.

Measuring outcome of total knee replacement using quality of life indices.

A series of 26 patients was studied before and after total knee replacement to determine the change in their quality of life, expressed as a gain in Quality Adjusted Life Years (QALYs). Global health status was assessed using the Nottingham Health Profile, disability by the Harris scale, pain by the McGill Pain Questionnaire, and anxiety and depression by the Hospital Anxiety and Depression Scale. Substantial reductions were found in pain, anxiety and depression, and a significant improvement was found in mobility. These data were used to generate a 'QALY' (Quality Adjusted Life Year) comparable to the measure used by Williams (1) in his comparative evaluation of medical and surgical treatments. A gain of only 0.42 QALY was found for knee replacement, which is about one-tenth the figure given by Williams for hip replacement. The difference appears to be attributable not to differences in the success of the operations, but rather to the scope that QALY calculations give for allocating comparable patients to different quality of life states. Tighter criteria are needed if QALYs are to be used to guide resource allocation.