Obesity has complex multifactorial aetiology. It has been suggested by many, but not all, reports that earlier pubertal maturation may increase adult obesity risk. We conducted a systemic review and meta-analysis in both women and men, and hypothesised that any association between pubertal timing and adult obesity is likely to be confounded by childhood adiposity. In addition, we investigated whether pubertal timing is related to other cardiometabolic risk and long-term cardiovascular morbidity/mortality. Literature search was undertaken using MEDLINE, EMBASE, Web of Knowledge and TRIP databases, with a hand search of references. Both authors independently reviewed and extracted pre-defined data from all selected papers. Meta-analyses were conducted using Review Manager (RevMan) 5.0.24. A total of 48 papers were identified. Out of 34 studies, 30 reported an inverse relationship between pubertal timing and adult body mass index (BMI), the main adiposity measure used. Meta-analysis of 10 cohorts showed association between early menarche (menarche <12 vs ≥12 years) and increased adult BMI, with a standardised mean difference of 0.34 kg m(-2) (95% confidence interval: 0.33-0.34). Heterogeneity was large (I(2)=92%) but reduced significantly when grouped by outcome age. Late menarche (menarche ≥15 vs <15 years) was associated with decreased adult BMI, with a standardised mean difference of -0.26 kg m(-2) (95% confidence interval: -0.36, -0.21) (seven cohorts). Only eight papers included data on childhood BMI; the majority reported that childhood BMI only partially attenuated association between early menarche and later obesity. Although not suitable for meta-analysis, data on cardiometabolic risk factors and puberty suggested negative association between earlier pubertal timing and cardiovascular mortality, hypertension, metabolic syndrome (MetS) and abnormal glycaemia. Earlier pubertal timing is predictive of higher adult BMI and greater risk of obesity. This effect appears to be partially independent of childhood BMI. Earlier pubertal development appears to also be inversely correlated with risk of other cardiometabolic risk factors and cardiovascular mortality. Further work is needed to examine potential mechanisms and the level at which interventions may be targeted.

AimBenefits of human breast milk (HM) in avoiding rapid infancy weight gain and later obesity could relate to its nutrient content. We tested the hypothesis that differential HM total calorie content (TCC) or macronutrient contents may be associated with infancy growth.Methods HM hindmilk samples were collected at ages 4–8 weeks from 614 mothers participating in a representative birth cohort, with repeated infancy anthropometry. HM triglyceride (fat), lipid analytes and lactose (carbohydrate) were measured by 1H‐NMR, and protein content by the Dumas method. TCC and %macronutrients were determined.ResultsIn 614 HM samples, fat content was as follows: [median(IQR)]: 2.6 (1.7–3.6) g/100 mL, carbohydrate: 8.6 (8.2–8.8) g/100 mL, protein: 1.2 (1.1–1.2) g/100 mL; TCC: 61.8 (53.7–71.3) kcal/100 mL. HM of mothers exclusively breast feeding vs. mixed feeding was more calorific with higher %fat, lower %carbohydrate and lower %protein. Higher HM TCC was associated with lower 12‐months body mass index (BMI)/adiposity, and lower 3–12 months gains in weight/BMI. HM %fat was inversely related to 3–12 months gains in weight, BMI and adiposity, whereas %carbohydrate was positively related to these measures. HM %protein was positively related to 12‐months BMI.Conclusion HM analysis showed wide variation in %macronutrients. Although data on milk intakes were unavailable, our findings suggest functional relevance of HM milk composition to infant growth.

Early life exposures and metabolic programming are associated with later disease risk. In particular lipid metabolism is thought to play a key role in the development of the metabolic syndrome and insulin resistance in later life. Investigative studies of metabolic programming are limited by the ethics and practicalities of sample collection in small infants. Dried blood spots on filter paper, derived from heel pricks are considered as the most suitable option for this age group. We validated a novel lipid profiling method, based on high resolution mass spectrometry to successfully determine the lipid composition of infants using dried blood spots. The spotting and air drying of blood on paper has noticeable effects on many of the lipids, leading to lipid oxidation and hydrolysis, which demand careful interpretation of the obtained data. We compared the lipid profiles from plasma or whole blood samples and the results from dried blood spots to determine if these revealed the same inter-subject differences. The results from dried blood spots were no less reproducible than other lipid profiling methods which required comparatively larger sample volumes. Therefore, lipid profiles obtained from dried blood spots can be successfully used to monitor infancy lipid metabolism and we show significant differences in the lipid metabolism of infants at age 3 versus 12 months.Electronic supplementary materialThe online version of this article (doi:10.1007/s11306-014-0628-z) contains supplementary material, which is available to authorized users.