Early causes of child obesity and implications for prevention

Child obesity is becoming a serious public health concern, and major research effort is being devoted both to understand its aetiology and to improve the effectiveness of prevention strategies. Early growth patterns, both prenatally and postnatally, are emerging as important markers of later obesity risk, with rapid neonatal weight gain a clear risk factor for later obesity and metabolic syndrome. Thus, in two distinct senses child obesity is a growing problem. The paper summarises current evidence on growth pattern and obesity, relating it to infant feeding practice and appetite regulation, and highlights the areas in which public health interventions are feasible. Of the conclusions drawn, one involves a futuristic solution to child obesity where neonates are given an infusion of the hormone leptin to reset their appetite regulation

Adult socioeconomic, educational, social, and psychological outcomes of childhood obesity: a national birth cohort study

Objectives: To assess adult socioeconomic, educational, social, and psychological outcomes of childhood obesity by using nationally representative data. Design: 1970 British birth cohort. Participants: 16 567 babies born in Great Britain 5-11 April 1970 and followed up at 5, 10, and 29-30 years. Main outcome measures: Obesity at age 10 and 30 years. Self reported socioeconomic, educational, psychological, and social outcomes at 30 years. Odds ratios were calculated for the risk of each adult outcome associated with obesity in childhood only, obesity in adulthood only, and persistent child and adult obesity, compared with those obese at neither period. Results: Of the 8490 participants with data on body mass index at 10 and 30 years, 4.3% were obese at 10 years and 16.3% at 30 years. Obesity in childhood only was not associated with adult social class, income, years of schooling, educational attainment, relationships, or psychological morbidity in either sex after adjustment for confounding factors. Persistent obesity was not associated with any adverse adult outcomes in men, though it was associated among women with a higher risk of never having been gainfully employed (odds ratio 1.9, 95% confidence interval 1.1 to 3.3) and not having a current partner (2.0, 1.3 to 3.3). Conclusions: Obesity limited to childhood has little impact on adult outcomes. Persistent obesity in women is associated with poorer employment and relationship outcomes. Efforts to reduce the socioeconomic and psychosocial burden of obesity in adult life should focus on prevention of the persistence of obesity from childhood into adulthood

Anthropometry and body composition of 18 year old men according to duration of breast feeding: birth cohort study from Brazil

Objective: To assess the association between duration of breast feeding and measures of adiposity in adolescence. Design: Population based birth cohort study. Setting: Pelotas, a city of 320 000 inhabitants in a relatively developed area in southern Brazil. Participants: All newborn infants in the city's hospitals were enrolled in 1982; 78.8% (2250) of all male participants were located at age 18 years when enrolling in the national army. Main outcome measures: Weight, height, sitting height, subscapular and triceps skinfolds, and body composition (body fat, lean mass). Results: Neither the duration of total breast feeding nor that of predominant breast feeding (breast milk plus non-nutritive fluids) showed consistent associations with anthropometric or body composition indices. After adjustment for confounding factors, the only significant associations were a greater than 50% reduction in obesity among participants breast fed for three to five months compared with all other breastfeeding categories (P = 0.007) and a linear decreasing trend in obesity with increasing duration of predominant breast feeding (P = 0.03). Similar significant effects were not observed for other measures of adiposity. Borderline direct associations also occurred between total duration of breast feeding and adult height (P = 0.06). Conclusions: The significant reduction in obesity among children breast fed for three to five months is difficult to interpret, as no a priori hypothesis existed regarding a protective effect of intermediate duration of breast feeding. The findings indicate that, in this population, breast feeding has no marked protective effect against adolescent adiposity

An ecological systems approach to examining risk factors for early childhood overweight: findings from the UK Millennium Cohort Study

Objective: To use an ecological systems approach to examine individual-, family-, community- and area-level risk factors for overweight (including obesity) in 3-year-old children. Methods: A prospective nationally representative cohort study conducted in England, Wales, Scotland, Northern Ireland. Participants included 13 188 singleton children aged 3 years in the Millennium Cohort Study, born between 2000 and 2002, who had complete height/weight data. The main outcome measure was childhood overweight (including obesity) defined by the International Obesity TaskForce cut-offs for body mass index. Results: 23.0% of 3-year-old children were overweight or obese. In the fully adjusted model, primarily individual- and family-level factors were associated with early childhood overweight: birthweight z-score (adjusted odds ratio, 1.36, 95% CI 1.30 to 1.42), black ethnicity (1.41, 1.11 to 1.80) (compared with white), introduction to solid foods or =21 hours/week (1.23, 1.10 to 1.37) (compared with never worked). Breastfeeding > or =4 months (0.86, 0.76 to 0.97) (compared with none) and Indian ethnicity (0.63, 0.42 to 0.94) were associated with a decreased risk of early childhood overweight. Children from Wales were also more likely to be overweight than children from England. Conclusions: Most risk factors for early childhood overweight are modifiable or would allow at-risk groups to be identified. Policies and interventions should focus on parents and providing them with an environment to support healthy behaviours for themselves and their children

Maternal employment and early childhood overweight: findings from the UK Millennium Cohort Study

Background: In most developed countries, maternal employment has increased rapidly. Changing patterns of family life have been suggested to be contributing to the rising prevalence of childhood obesity. Objectives: Our primary objective was to examine the relationship between maternal and partner employment and overweight in children aged 3 years. Our secondary objective was to investigate factors related to early childhood overweight only among mothers in employment. Design: Cohort study. Subjects: A total of 13 113 singleton children aged 3 years in the Millennium Cohort Study, born between 2000 and 2002 in the United Kingdom, who had complete height/weight data and parental employment histories. Measurements: Parents were interviewed when the child was aged 9 months and 3 years, and the child's height and weight were measured at 3 years. Overweight (including obesity) was defined by the International Obesity Task Force cut-offs. Results: A total of 23% (3085) of children were overweight at 3 years. Any maternal employment after the child's birth was associated with early childhood overweight (odds ratio (OR) [95% confidence interval (CI)]; 1.14 [1.00, 1.29]), after adjustment for potential confounding and mediating factors. Children were more likely to be overweight for every 10 h a mother worked per week (OR [95% CI]; 1.10 [1.04, 1.17]), after adjustment. An interaction with household income revealed that this relationship was only significant for children from households with an annual income of pound33 000 ($57 750) or higher. There was no evidence for an association between early childhood overweight and whether or for how many hours the partner worked, or with mothers' or partners' duration of employment. These relationships were also evident among mothers in employment. Independent risk factors for early childhood overweight were consistent with the published literature. Conclusions: Long hours of maternal employment, rather than lack of money may impede young children's access to healthy foods and physical activity. Policies supporting work-life balance may help parents reduce potential barriers

Regional differences in overweight: an effect of people or place?

Objective: To examine UK country and English regional differences in childhood overweight (including obesity) at 3 years and determine whether any differences persist after adjustment for individual risk factors. Design: Nationally representative prospective study. Setting: England, Wales, Scotland and Northern Ireland. Participants: 13 194 singleton children from the UK Millennium Cohort Study with height and weight data at age 3 years. Main outcome measure: Overweight (including obesity) was defined according to the International Obesity TaskForce cut-offs for body mass index, which are age and sex specific. Results: At 3 years of age, 23% (3102) of children were overweight or obese. In univariable analyses, children from Northern Ireland (odds ratio 1.30, 95% confidence interval 1.14 to 1.48) and Wales (1.26, 1.11 to 1.44) were more likely to be overweight than children from England. There were no differences in overweight between children from Scotland and England. Within England, children from the East (0.71, 0.57 to 0.88) and South East regions (0.82, 0.68 to 0.99) were less likely to be overweight than children from London. There were no differences in overweight between children from other English regions and children from London. These differences were maintained after adjustment for individual socio-demographic characteristics and other risk factors for overweight. Conclusions: UK country and English regional differences in early childhood overweight are independent of individual risk factors. This suggests a role for policies to support environmental changes that remove barriers to physical activity or healthy eating in young children

Practice pointer: Using the new UK-WHO growth charts

The new UK growth charts for children aged 0-4 years (designed using data from the new WHO standards) describe the optimal pattern of growth for all children, rather than the prevailing pattern in the UK (as with previous charts). The new charts are suitable for all ethnic groups and set breast feeding as the norm. UK children match the new charts well for length and height, but after age 6 months fewer children will be below the 2nd centile for weight or show weight faltering, and more will be above the 98th centile. The new charts look different: they have a separate preterm section, no lines between 0 and 2 weeks, and the 50th percentile is no longer emphasised. The charts give clear instructions on gestational correction, and there is a new chart for infants born before 32 weeks’ gestation. The instructions advise on when and how to measure and when a measurement or growth pattern is outside the normal range. The charts include a “look-up” tool for determining the body mass index centile from height and weight centiles without calculation and aid for predicting adult height. The charts and supporting educational materials can be downloaded from www.growthcharts.rcpch.ac.u

Identifying the best body mass index metric to assess adiposity change in children.

OBJECTIVE: Although dual-energy X-ray absorptiometry (DEXA) is the preferred method to estimate adiposity, body mass index (BMI) is often used as a proxy. However, the ability of BMI to measure adiposity change among youth is poorly evidenced. This study explored which metrics of BMI change have the highest correlations with different metrics of DEXA change. METHODS: Data were from the Quebec Adipose and Lifestyle Investigation in Youth cohort, a prospective cohort of children (8-10 years at recruitment) from Québec, Canada (n=557). Height and weight were measured by trained nurses at baseline (2008) and follow-up (2010). Metrics of BMI change were raw (ΔBMIkg/m(2) ), adjusted for median BMI (ΔBMIpercentage) and age-sex-adjusted with the Centers for Disease Control and Prevention growth curves expressed as centiles (ΔBMIcentile) or z-scores (ΔBMIz-score). Metrics of DEXA change were raw (total fat mass; ΔFMkg), per cent (ΔFMpercentage), height-adjusted (fat mass index; ΔFMI) and age-sex-adjusted z-scores (ΔFMz-score). Spearman's rank correlations were derived. RESULTS: Correlations ranged from modest (0.60) to strong (0.86). ΔFMkg correlated most highly with ΔBMIkg/m(2) (r = 0.86), ΔFMI with ΔBMIkg/m(2) and ΔBMIpercentage (r = 0.83-0.84), ΔFMz-score with ΔBMIz-score (r = 0.78), and ΔFMpercentage with ΔBMIpercentage (r = 0.68). Correlations with ΔBMIcentile were consistently among the lowest. CONCLUSIONS: In 8-10-year-old children, absolute or per cent change in BMI is a good proxy for change in fat mass or FMI, and BMI z-score change is a good proxy for FM z-score change. However change in BMI centile and change in per cent fat mass perform less well and are not recommended

Micronutrients: highlights and research challenges from the 1994-5 National Diet and Nutrition Survey of people aged 65 years and over

The aims of the National Diet and Nutrition Survey series are summarized, and the new National Diet and Nutrition Survey of people aged 65 years and over is explored, with particular emphasis on micronutrient intakes and status indices. Mean nutrient intakes were generally satisfactory for most micronutrients, but intakes of vitamin D, Mg, K and Cu were low. Intakes of vitamin D were far below the reference nutrient intake for people aged 65 years and over, and there was also biochemical evidence of vitamin D deficiency, for 8% of free-living and 37% of institution participants, attributed partly to limited exposure to sunlight. A substantial proportion of people living in institutions had inadequate biochemical status indices, notably for vitamin C, Fe and folate. Relationships between intake and status were close for vitamins. Mineral intakes did not correlate well with currently used status indices. Some intakes and indices, especially those of vitamin C, carotenoids, Na and K, were strongly correlated with socio-economic status and with north-south gradients in Britain. Future research challenges should address the functional and health significance of low intakes and sub-optimal biochemical indices for certain micronutrients, especially for people living in institutions; the shortcomings of mineral status indices especially as indicators of mineral intake; the social and geographical inequalities of micronutrient intakes and status, and why micronutrient status deteriorates with increasing age. The answers to these questions will help to define the characteristics of nutritional risk for older people in Britain, and to clarify future needs for education and intervention