Child temperament does not predict adolescent body composition in girls

Does Childhood Temperamental Activity Predict Physical Activity and Sedentary Behavior over a 30-Year Period? Evidence from the Young Finns Study

PURPOSE

We examined associations between childhood temperamental activity, physical activity (PA), and television (TV) viewing over a 30-year period.

METHOD

The participants (1220 boys and 1237 girls) were aged 3, 6, 9, and 12 years in 1980 and were followed until 2011. Temperamental activity was evaluated by participants' mothers at baseline. The PA was assessed based on maternal ratings of the child from ages 3 to 6 and via self-report age from the age of 9 across all measurements. TV viewing was assessed using self-reports taken from 2001 to 2011. The associations between temperamental activity and the level and change of PA and TV viewing were determined using linear growth modeling stratified by gender and age group.

RESULTS

High temperamental activity assessed from ages 9 to 12 was associated with high levels of childhood PA in both genders, but with a steeper decline in PA levels during the first 9 years of follow-up in boys. High temperamental activity assessed from ages 3 to 6 was associated with the decline of PA from childhood to youth in girls. High childhood temperamental activity was associated with decreased levels of PA in adulthood in men, but not in women. The associations between childhood temperamental activity and TV viewing during adulthood seemed to be positive but not consistently significant in all age and gender groups.

CONCLUSION

High temperamental activity may contribute to the development of a physically inactive lifestyle. More evidence is needed with regard to gender differences among participants in similar study settings.

Infant temperament and eating style predict change in standardized weight status and obesity risk at 6 years of age

OBJECTIVE

Little research has addressed the relationships among infant temperament, eating styles and obesity risk. To address this gap, we tested whether infant temperament and eating patterns at the age of 1 year are associated with a greater increase in standardized weight status, and greater obesity risk at 6 years of age.

DESIGN

A secondary, prospective analysis of the Colorado Adoption Study was conducted. The main predictor variables were infant temperament (that is, emotionality, activity, attention span-persistence, reaction to food and soothability) and eating domains (that is, reactivity to food, predictable appetite and distractability at mealtime) at the age of 1 year, along with the body mass index (BMI) of biological mothers. The outcome measures were child weight and height (length) assessed at ages 1 through 6 years, from which weight-for-length and BMI were computed along with the standardized indexes (z-scores) and percentiles. Overweight/obesity status was computed at each year as well.

PARTICIPANTS

A primarily White sample of 262 boys and 225 girls, assessed at ages 1 through 6 years, along with their mothers.

RESULTS

Among boys, greater attention span-persistence was associated with reduced standardized weight status gain (β=-0.15, P<0.05) and reduced obesity risk (odds ratio (OR)=0.46, P=0.06). Among girls, greater soothability and negative reaction to food were associated with greater standardized weight status gain (β=0.19, P<0.01; and β=0.16, P<0.05, respectively) and increased obesity risk (OR=3.72, P=0.03; and OR=2.81, P=0.08, respectively). Biological mothers' obesity status predicted obesity risk in boys (OR=3.07, P=0.01) and girls (OR=5.94, P=0.03).

CONCLUSIONS

Male infants with less attention span, and female infants with greater soothability or a more negative food reaction, showed greater increases in standardized weight and were more likely to be overweight/obese at the age of 6 years. The role of infant temperament in pediatric obesity onset warrants greater research.

Influence of serum leptin on weight and body fat growth in children at high risk for adult obesity

OBJECTIVE

Our objective was to examine serum leptin prospectively as a predictor of weight and body fat growth in children at high risk for adult obesity. We hypothesized that leptin measurements would be positively associated with increased growth of adipose tissue because children with high baseline leptin for their body fat mass have greater leptin resistance and thus would have greater susceptibility to weight gain.

METHODS

Children ages 6-12 yr at high risk for adult obesity because of early-onset childhood overweight and/or parental overweight were recruited from 1996-2004. Growth in body mass index (BMI) was studied in 197 children, and growth in total body fat mass was examined in 149 children over an average follow-up interval of 4.4 yr (range, 1-8 yr). Longitudinal analyses accounted for sex, race, socioeconomic status, initial body composition, age, skeletal age, and physical activity and included all available interim visits for each individual so that a total of 982 subject visits were included in the analysis.

RESULTS

At baseline, 43% of children studied were overweight (BMI > or = 95th percentile); during follow-up, an additional 14% became overweight. Independent of initial body composition, baseline leptin was a statistically significant positive predictor of increased BMI (P = 0.0147) and increased total body fat mass (P < 0.007).

CONCLUSIONS

High serum leptin, independent of body fat, may be an indicator of increased leptin resistance, which predisposes children at high risk for adult obesity to somewhat greater growth in weight and body fat during childhood.

Physical activity and sedentary behavior: a review of longitudinal studies of weight and adiposity in youth

AIM

To review the published prospective observational studies of the relationship of physical activity and sedentary behavior with the development of overweight and adiposity, with an emphasis on methodologic issues.

METHODS

Sample size, population studied, length of follow-up, assessment of exposure (physical activity, inactivity, or sedentary behavior), assessment of outcome (relative weight, overweight, % body fatness, adiposity), statistical approach, and main findings were extracted, summarized, and key methodological issues highlighted.

RESULTS

In total, 17 studies of physical activity and 15 studies of inactivity/sedentary behavior were identified; as these were not mutually exclusive, 20 unique studies were reviewed. Results were mixed, with most studies showing an inverse association of physical activity with weight or fatness outcomes and/or a direct association of inactivity/sedentary behavior with weight or fatness outcomes. The effects identified were generally of small magnitude. Imprecise measurement of activity exposures likely weakens the observed relationships. Most studies used a pre-post design and had limited duration of follow-up (< or = 2y). Studies with longer and more frequent follow-up did not always use the most advantageous statistical approach.

CONCLUSIONS

On balance, the available evidence from prospective observational studies suggests that increased physical activity and decreased sedentary behavior are protective against relative weight and fatness gains over childhood and adolescence. In addition to improved measurement methods, longer and more frequent follow-up as well as truly longitudinal analysis methods would help establish these important prevention and intervention targets, and identify subgroups or development periods where interventions would likely be effective.