Julie Lanigan

Nutrition in infancy and long-term risk of obesity: evidence from 2 randomized controlled trials

BACKGROUND Growth acceleration as a consequence of relative overnutrition in infancy has been suggested to increase the risk of later obesity. However, few studies have investigated this association by using an experimental study design. OBJECTIVE We investigated the effect of early growth promotion on later body composition in 2 studies of infants born small for gestational age (weight <10th percentile in study 1 and <20th percentile in study 2). DESIGN We reviewed a subset of children (n = 153 of 299 in study 1 and 90 of 246 in study 2) randomly assigned at birth to receive either a control formula or a nutrient-enriched formula (which contained 28-43% more protein and 6-12% more energy than the control formula) at 5-8 y of age. Fat mass was measured by using bioelectric impedance analysis in study 1 and deuterium dilution in study 2. RESULTS Fat mass was lower in children assigned to receive the control formula than in children assigned to receive the nutrient-enriched formula in both trials [mean (95% CI) difference for fat mass after adjustment for sex: study 1: -38% (-67%, -10%), P = 0.009; study 2: -18% (-36%, -0.3%), P = 0.04]. In nonrandomized analyses, faster weight gain in infancy was associated with greater fat mass in childhood. CONCLUSIONS In 2 prospective randomized trials, we showed that a nutrient-enriched diet in infancy increased fat mass later in childhood. These experimental data support a causal link between faster early weight gain and a later risk of obesity, have important implications for the management of infants born small for gestational age, and suggest that the primary prevention of obesity could begin in infancy.

Number of days needed to assess energy and nutrient intake in infants and young children between 6 months and 2 years of age

Objective: To estimate the minimum number of days of recorded dietary intake needed to place infants and young children into thirds of a population distribution with an acceptable degree of accuracy.Design: Dietary intake data collected from 5-day weighed food records for 72 infants and young children up to 2 y of age, collected during a cross-sectional study, were analysed to estimate the number of recording days necessary to assess intake of energy and 10 nutrients.Setting: Community study among healthy infants and children.Subjects: Parents attended recruitment sessions in local community areas. In total, 72 subjects were entered into the study and all completed the 5-day dietary assessment period.Interventions: A 5-day weighed record of childrens dietary intake was made by the parents or regular carer.Results: Mean within subject standard deviations were smaller than mean between subject standard deviations with respect to energy (778 vs 824 kJ/day), macronutrient subclasses: protein (8 vs 9.4 g/day); fat (9 vs 10 g/day); and carbohydrate (26 vs 29 g/day) and for specific micronutrients: calcium (163 vs 236 mg/day); phosphorus (143 vs 270 mg/day); magnesium (25 vs 43 mg/day); iron (2 vs 3 mg/day); zinc (1 vs 1.3 mg/day); ascorbic acid (27 vs 64 mg/day) and retinol equivalents (281 vs 424 μg/day). Estimated number of days of food records necessary to assess intake of energy, protein, fat and carbohydrate with acceptable degree of accuracy were 5,4,4 and 3, respectively. For all the micronutrients included in this analysis 2 days of recording were necessary.Conclusions: Compared with adults and older children, fewer days are needed to classify this age group into thirds of the distribution with an acceptable degree of accuracy according to intake of energy and specific nutrients.Sponsorship: The data collection phase of this study was supported by a grant from the Procter and Gamble Company, Cincinnati, OH, USA.

Prevention of obesity in preschool children.

Obesity is a serious problem that affects children from diverse ethnic backgrounds in both industrialised and developing countries. Worldwide, an estimated twenty-two million children <5 years of age were overweight in 2007. In the UK if current trends continue an estimated one-quarter of all children <16 years of age will be obese by 2050. Recent evidence suggests that most obesity is established during the preschool years, and because one in five obese 4 year olds will become obese adults this situation has major implications for public health. The causes of obesity in preschool children are complex and multifactorial. Although 30-50% of the predisposition towards obesity in preschool children can be explained by genetic factors, environmental influences also play a crucial role. The preschool period in particular is a pivotal time during which long-term dietary and physical activity habits are established, with potential lifelong effects on health. However, research in this age-group is limited. Previous studies have aimed to improve diet, increase physical activity and achieve behavioural change. However, few of these studies have been successful and there is an urgent need, therefore, for the development of evidence-based interventions aimed at the prevention of preschool obesity.

The Effect of Intrauterine Growth on Verbal IQ Scores in Childhood: A Study of Monozygotic Twins

OBJECTIVE: Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether children within-pair differences in birth weight were related to within-pair differences in IQ scores. METHODS: A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scale for Children, Third Edition, was administered, and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores. RESULTS: VIQ but not PIQ score was affected by prenatal growth restriction. The results suggest that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins. CONCLUSIONS: Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parental IQ and education and infant gender, age, genetic characteristics, and gestation.

Developmental trajectories of grey and white matter in dyscalculia

Abstract Developmental dyscalculia is a significant neural deficit with broad social impact. A number of techniques have been used to identify the brain basis of dyscalculia, and many of these have highlighted the role of the intraparietal sulci and a left fronto-parietal network in the representation of core number skills. These studies offer conflicting explanations of the neurobiological deficits associated with dyscalculia, and to date few studies have elucidated the timeline of cortical changes involved. Here we report a volumetric study comparing well-characterized dyscalculic learners aged from 8 to 14 years with tightly matched controls. Using automated cortical parcellation of anatomical MRI, we show that the posterior parietal and fronto-parietal systems in dyscalculia may undergo abnormal development during the pre-teenage and teenage years. As a result, the present study more clearly characterizes the underlying neural basis of dyscalculia than previous studies have hitherto achieved.