A five year longitudinal study investigating the prevalence of childhood obesity: comparison of BMI and waist circumference.

Objective: The purpose of this study was to examine the prevalence of obesity over time in the same individuals comparing body mass index (BMI), waist circumference (WC) and waist to height ratio (WHtR). Study design: Five year longitudinal repeated measures study (2005–2010). Children were aged 11–12 (Y7) years at baseline and measurements were repeated at age 13–14 (Y9) years and 15–16 (Y11) years. Methods: WC and BMI measurements were carried out by the same person over the five years and raw values were expressed as standard deviation scores (sBMI and sWC) against the growth reference used for British children. Results: Mean sWC measurements were higher than mean sBMI measurements for both sexes and at all assessment occasions and sWC measurements were consistently high in girls compared to boys. Y7 sWC = 0.792 [95% confidence interval (CI) 0.675–0.908], Y9 sWC = 0.818 (95%CI 0.709–0.928), Y11 sWC = 0.943 (95%CI 0.827–1.06) for boys; Y7 sWC = 0.843 (0.697–0.989), Y9 sWC = 1.52 (95%CI 1.38–0.67), Y11 sWC = 1.89 (95%CI 1.79–2.04) for girls. Y7 sBMI = 0.445 (95%CI 0.315–0.575), Y9 sBMI = 0.314 (95%CI 0.189–0.438), Y11 sBMI = 0.196 (95%CI 0.054–0.337) for boys; Y7 sBMI = 0.353 (0.227–0.479), Y9 sBMI = 0.343 (95%CI 0.208–0.478), Y11 sBMI = 0.256 (95%CI 0.102–0.409) for girls. The estimated prevalence of obesity defined by BMI decreased in boys (18%, 12% and 10% in Y 7, 9 and 11 respectively) and girls (14%, 15% and 11% in Y 7, 9 and 11). In contrast, the prevalence estimated by WC increased sharply (boys; 13%, 19% and 23%; girls, 20%, 46% and 60%). Conclusion: Central adiposity, measured by WC is increasing alongside a stabilization in BMI. Children appear to be getting fatter and the additional adiposity is being stored centrally which is not detected by BMI. These substantial increases in WC are a serious concern, especially in girls

Relationships between temperament and eating behaviours in young children

This study examined the associations between eating behaviours and temperament in a sample of young children. Mothers (N=241) of children aged 3-8 years completed measures of their children's eating behaviours and temperament and reported their child's height and weight. Children with more emotional temperaments were reported to display more food avoidant eating behaviours. Shyness, sociability and activity were not related to children's eating behaviours. Higher child BMI was related to more food approach eating behaviours but BMI was unrelated to child temperament. Future research should explore more specifically how emotional temperaments might influence child eating behaviour

The importance of mealtime structure for reducing child food fussiness

The aim of this study was to explore how the structure of mealtimes within the family setting is related to children's fussy eating behaviours. Seventy-five mothers of children aged between 2 and 4 years were observed during a typical mealtime at home. The mealtimes were coded to rate mealtime structure and environment as well as the child's eating behaviours (food refusal, difficulty to feed, eating speed, positive and negative vocalisations). Mealtime structure emerged as an important factor which significantly distinguished children with higher compared with lower levels of food fussiness. Children whose mothers ate with their child and ate the same food as their child were observed to refuse fewer foods and were easier to feed compared with children whose mothers did not. During mealtimes where no distractors were used (e.g. no TV, magazines or toys), or where children were allowed some input into food choice and portioning, children were also observed to demonstrate fewer fussy eating behaviours. Findings of this study suggest that it may be important for parents to strike a balance between structured mealtimes, where the family eats together and distractions are minimal, alongside allowing children some autonomy in terms of food choice and intake

Emotion regulation styles as longitudinal predictors of compulsive exercise : a twelve month prospective study

Exercise can be used as a mood regulator but, in the eating disorder literature, exercise has sometimes been found to be compulsive, detrimental to physical health, and regarded as one maladaptive strategy used to regulate emotions. This study examined longitudinal associations between emotion regulation styles and this compulsive exercise in 572 adolescents who completed measures of compulsive exercise and emotion regulation. Twelve months later they completed measures of compulsive exercise. Compulsive exercise was predicted by Internal Dysfunctional emotion regulation in girls and boys, even after controlling for initial levels of compulsive exercise. Adolescents displaying compulsivity to exercise may require intervention programmes to alter their emotion regulation strategies

Sociocultural risk factors for compulsive exercise : a prospective study of adolescents

The risk factors for compulsive exercise are unknown. This study aims to explore longitudinal sociocultural risk factors for compulsive exercise, using a 12-month prospective design. A sample of 332 male and female adolescents (aged 13–15 years at baseline) completed self-report measures of sociocultural risk factors and compulsive exercise at baseline and eating disorder psychopathology and compulsive exercise at 12-month follow-up assessment. Hierarchical regressions found that family and peer messages to become more muscular predicted compulsive exercise in boys, whereas feeling pressure from the media to be thin was a significant predictor of compulsive exercise in girls. These relationships remained significant when controlling for eating disorder psychopathology but became nonsignificant when initial levels of compulsive exercise were entered into the model. The findings suggest that sociocultural risk factors may contribute to the development of compulsive exercise but future research should utilise a younger sample and employ a longer follow-up period to identify true longitudinal effects

Leptin may play a role in bone microstructural alterations in obese children.

Bone mass is low and fracture risk is higher in obese children. Hormonal changes in relation to skeletal microstructure and biomechanics have not been studied in obese children