Preventing childhood obesity: can we do it?

Differences in the nutritional content of baby and toddler foods with front-of-package nutrition claims issued by manufacturers v. governments/health organizations

Objective

Nutritional information panels are required on all packaged food products in the USA, yet are perceived as difficult to use by consumers. Nutritional symbols have been developed by various groups to assist consumers in making healthier food purchases. Different nutritional criteria are used depending on the authorizing body of these symbols. The present study assesses the nutrient profile of baby and toddler foods in light of their accompanying nutritional symbols.

Design

Kruskal–Wallis and χ2 tests were used to assess differences in the nutritional content of products based on the presence and issuing body of nutritional symbols.

Setting

Nine grocery, drug and department stores in Philadelphia, PA, USA.

Subjects

Two hundred and forty packaged baby and toddler foods.

Results

Products whose nutritional symbol was issued by government/health professionals contained significantly more Ca (P = 0·002), fibre (P = 0·001), protein (P = 0·005), vitamin A (P = 0·011), vitamin C (P < 0·001) and Zn (P < 0·001) and less sugar (P = 0·004) per serving than products without a nutritional symbol and products whose nutritional symbol was issued by the manufacturer.

Conclusions

Products with a nutritional symbol issued by government/health professionals were healthier than foods with nutritional symbols issued by the manufacturer directly and foods with no nutritional symbols.

Risk factors for overweight/obesity in preschool children: an ecological approach

BACKGROUND

Identification of risk factors is critical to preventing the childhood obesity epidemic. Risk factors that contribute to obesity are multifactorial. However, limited research has focused on identifying obesity risk factors using an ecological approach.

METHODS

Baseline self-report survey data from the STRONG Kids program were used. The sample consisted of 329 parent-child dyads recruited from childcare programs in east-central Illinois. Child height and weight were measured and converted to age- and sex-specific z-scores using standard growth charts. An ecological model provided the theoretical framework for the selection of 22 previously reported childhood obesity risk factors. Multiple logistic regression analyses were used to identify risk factors.

RESULTS

Of 22 potential risk factors, three were found to be significantly associated with child overweight/obesity. These included child nighttime sleep duration (χ(2)=8.56; p=0.003), parent BMI (χ(2)=5.62; p=0.01), and parental restrictive feeding for weight control (χ(2)=4.77; p=0.02). Children who slept for 8 hours and less were 2.2 times more likely to be overweight/obese [95% confidence interval (CI): 1.3-3.7), whereas children with an overweight/obese parent were 1.9 times more likely to be overweight/obese (95% CI: 1.12-3.2). Finally, children whose parents used restrictive feeding practices were 1.75 times more likely to be overweight/obese (95% CI: 1.06-2.9).

CONCLUSIONS

Using an ecological approach, we conclude that childhood obesity prevention efforts may benefit from targeting the key risk factors of child sleep duration, parent BMI, and parental restrictive feeding practices as focus areas for obesity prevention.

Causes of increased energy intake among children in the U.S., 1977-2010

BACKGROUND

Changes in total energy intake have been reported among children and adolescents, but the extent to which the components of total energy-energy density; portion size; and the number of eating/drinking occasions (EO)-drive these changes is unknown.

PURPOSE

The objective of the current study was to examine the relative contribution to changes in daily total energy.

METHODS

Using cross-sectional nationally representative data from the Nationwide Food Consumption Survey (1977-1978); the Continuing Survey of Food Intake of Individuals (1989-1991); and the National Health and Nutrition Examination Surveys (1994-1998 and 2005-2010) for children and adolescents (aged 2-18 years), changes in total energy (kcal/day) were mathematically decomposed to determine the relative contributions of its three component parts: portion size (g/EO); energy density (kcal/g/EO); and eating/drinking occasions (n). Analyses were completed in 2012.

RESULTS

Over the full period, there was an increase in total energy intake (+108 kcal/day) and the number of daily eating/drinking occasions (+1.2). The average portion size per eating/drinking occasion increased between 1977-1978 and 1989-1991, and then dropped by about 85 g/EO between 1989-1991 and 2005-2010. The average energy density per eating/drinking occasion has fluctuated over time, reaching its highest level in 2005-2010 (1.24 kcal/g/EO). The decomposition results show that between 1977-1978 and 2005-2010, changes in the number of eating/drinking occasions per day and portion size per eating occasion were the largest contributors to annualized changes in daily total energy (+19 and -13 kcal/day/year, respectively). Variations in trends were observed for race/ethnicity and parental education subgroups.

CONCLUSIONS

These findings highlight potentially important intervention targets for reducing energy imbalances in U.S. youth.

Children's aerobic fitness and academic achievement: a longitudinal examination of students during their fifth and seventh grade years

OBJECTIVES

We assessed children's potential differences in academic achievement based on aerobic fitness over a 2-year period.

METHODS

The longitudinal study sample included 3 cohorts of students (n = 1725; 50.1% male) enrolled in a West Virginia public school system. Students received baseline fitness and academic assessments as fifth graders and at a 2-year follow-up assessment. We used FitnessGram to assess fitness in aerobic capacity and WESTEST, a criterion-based assessment, for academic performance.

RESULTS

Students who stayed in the healthy fitness zone (HFZ) had significantly higher WESTEST scores than did students who stayed in the needs improvement zone (NIZ). Students who moved into or out of the HFZ occasionally had significantly higher WESTEST scores than did students who stayed in the NIZ, but they were rarely significantly lower than those of students who stayed in the HFZ.

CONCLUSIONS

Students' aerobic capacity is associated with greater academic achievement as defined by standardized test scores. This advantage appears to be maintained over time, especially if the student stays in the HFZ.

Impacts of infancy rapid weight gain on 5-year childhood overweight development vary by age and sex in China

OBJECTIVES

To investigate the critical period for overweight development during early childhood by examining growth trajectory and related sex differences.

METHODS

Using piecewise linear mixed models and logistic regression, we examined the effect of growth trajectory at different periods on overweight at age 4-5 by sex among 13,6 971 regularly followed children (mean: 12.2 times) during 2000-2005 in south China.

RESULTS

The high-body mass index (BMI) group (>top tertile of BMI Z score at age of 4-5 years) had faster growth rates of BMI, BMI Z score, weight and height than the low-BMI group in the first 3 months of life. Boys were more likely to be overweight [odds ratio (OR) = 2.0, 95% confidence interval: 1.5-2.7] than girls; the male high-BMI group had higher growth rates during the first 3 months than girls with high-BMI, independently of environmental factors. Those fast grown (in the upper tertile of growth rates in BMI and BMI Z score) in periods 0-3 months had relatively higher OR of at risk of overweight at age of 4-5 years than those in other periods.

CONCLUSIONS

Overweight risk develops during the first 3 months of life. Boys have an earlier peak in growth than girls, which may help explain why overweight is more prevalent in boys in China.

Parental factors associated with walking to school and participation in organised activities at age 5: analysis of the Millennium Cohort Study

Background

Physical activity is associated with better health. Two sources of activity for children are walking to school and taking part in organised sports and activities. This study uses a large national cohort to examine factors associated with participation in these activities.

Methods

The Millennium Cohort study contains 5 year follow-up of 17,561 singleton children recruited between 2000-2002 in the UK. All participants were interviewed in their own homes at 9 months, 3 years and 5 years follow-up and all measures were self reports. Logistic regression and likelihood ratio tests were used.

Results

Children are less likely to walk to school as income and parental education increase [Adjusted odds: 0.7 (95%CI: 0.6-0.8) for higher income/education compared to low income/no qualifications]. However, if the parent plays with the child in high income families the child is more likely to walk to school [Adjusted odds: 1.67 (95%CI: 1.3-2.1)]. Children taking part in organised activities are from higher income, higher education families, with a car, in a "good" area with non-working mothers. However, in low socio-economic families where the parent plays with the child the child is more likely to take part in organised activities [Adjusted odds: 2.0 (95% CI: 1.5-2.7)].

Conclusions

Income is an important determinant of the type of activity available to children. Families that report good health behaviours (non-smoking, low TV viewing) and play with their children show higher levels of physical activity. Thus, parenting practice appears to have a strong impact on their child's physical activity.

Teens and screens: the influence of screen time on adiposity in adolescents

The effect of screen time during secondary school on percent body fat was examined in a cohort of 744 Canadian adolescents aged 12-13 years at baseline. Participants completed self-reported questionnaires on television viewing and computer use in 19 survey cycles over 57 months from 1999 to 2005. Triceps skinfold thickness and subscapular skinfold thickness were measured in survey cycles 1 and 19. Four screen-time trajectory groups identified in growth mixture modeling included steady-low screen time (73% of the sample), steady-high (10%), increasers (9%), and decreasers (8%). The effect of screen-time trajectory on percent body fat at survey cycle 19 was modeled in boys and girls separately by using linear regression, adjusting for baseline percent body fat and physical activity. Relative to that of steady-low screen-time trajectory group boys, percent body fat was 2.9 (95% confidence interval: 0.7, 5.0) and 2.4 (95% confidence interval: 0.5, 4.2) percentage units higher on average among "increasers" and "steady-high" trajectory group boys, respectively. There was no evidence that screen time has an effect on percent body fat in girls overall, although physical activity modified the association between screen time and percent body fat in both sexes. Efforts to prevent obesity in youth should emphasize reducing screen time.

Interplay between weight loss and gut microbiota composition in overweight adolescents

The aim of this study was to determine the influence of an obesity treatment program on the gut microbiota and body weight of overweight adolescents. Thirty-six adolescents (13-15 years), classified as overweight according to the International Obesity Task Force BMI criteria, were submitted to a calorie-restricted diet (10-40%) and increased physical activity (15-23 kcal/kg body weight/week) program over 10 weeks. Gut bacterial groups were analyzed by quantitative real-time PCR before and after the intervention. A group of subjects (n=23) experienced >4.0 kg weight loss and showed significant BMI (P=0.030) and BMI z-score (P=0.035) reductions after the intervention, while the other group (n=13) showed <2.0 kg weight loss. No significant differences in dietary intake were found between both groups. In the whole adolescent population, the intervention led to increased Bacteroides fragilis group (P=0.001) and Lactobacillus group (P=0.030) counts, and to decreased Clostridium coccoides group (P=0.028), Bifidobacterium longum (P=0.031), and Bifidobacterium adolescentis (P=0.044) counts. In the high weight-loss group, B. fragilis group and Lactobacillus group counts also increased (P=0.001 and P=0.007, respectively), whereas C. coccoides group and B. longum counts decreased (P=0.001 and P=0.044, respectively) after the intervention. Total bacteria, B. fragilis group and Clostridium leptum group, and Bifidobacterium catenulatum group counts were significantly higher (P<0.001-0.036) while levels of C. coccoides group, Lactobacillus group, Bifidobacterium, Bifidobacterium breve, and Bifidobacterium bifidum were significantly lower (P<0.001-0.008) in the high weight-loss group than in the low weight-loss group before and after the intervention. These findings indicate that calorie restriction and physical activity have an impact on gut microbiota composition related to body weight loss, which also seem to be influenced by the individual's microbiota.

Eating late in the evening is associated with childhood obesity in some age groups but not in all children: the relationship between time of consumption and body weight status in U.S. children

Background

Some studies in adults indicate a positive correlation between eating later in the day and overall energy intake as well as body weight status. Thus, the time of food intake may be a risk factor in childhood obesity. This study was designed to describe the proportion of energy consumed in the time from 4 pm to midnight measured in two-hour increments and to determine a potential association between the time of proportion of energy consumed and body weight status.

Methods

Dietary, anthropometric, and socio-demographic data of 2–18 year olds (N = 11,072) of the National Health and Nutrition Examination Survey (NHANES) 1999–2004 was examined to describe the proportion of total energy consumed within two-hour time periods between 4 pm and midnight. To examine the potential association between eating later in the day and body weight status, generalized estimating equations (GEE) models were used to quantify the effect of time trends (proportion of total energy consumed in each 2-hour time period from 4 pm to 11.59 pm) on body weight status. Analysis was conducted in the total sample and in subgroups stratified by sex, ethnic group (Non-Hispanic white, Non-Hispanic black, Mexican American, Other Hispanic, and Other Race including multi-racial) and age group (2–5, 6–11, and 12–18 year olds). Complex sample survey analysis were used to assess differences at a significance level of p-value < 0.05.

Results

Proportion of energy consumed varied by sex, ethnic group, and age groups between 4 pm and 11.59 pm. Compared to healthy weight children, overweight school-age children consumed significantly higher while overweight adolescents consumed significantly lower proportions of total daily energy with each advancing two-hour time increment.

Conclusion

The association between the circadian rhythm of eating and body weight status needs to be investigated further to examine the effect of time of consumption on the risk of childhood obesity. Especially longitudinal studies in diverse child populations would help elucidate the importance of time of eating on obesity.

Subtyping dietary restraint and negative affect in a longitudinal community sample of girls

OBJECTIVE

This study tests the validity of the "dietary-depressive" subtype (typified by greater negative affect) and a "dietary" subtype (typified by dietary restraint only) using a diverse longitudinal community sample.

METHOD

Girls at ages 10, 12, and 14 completed the Child Eating Attitudes Test, the Child Symptom Inventory-4, and Body Image Measure. Body Mass Index was assessed at each age.

RESULTS

Unlike previous studies, cluster analysis revealed an at-risk "dietary-depressive" (R+) subtype (18.7%,100/534) and a not at-risk (R-) subtype, distinguished by few depressive symptoms and little dietary restraint (81.3%,434/534), but no "dietary" subtype. When compared with the R- subtype, the R+ subtype had significantly greater eating disordered behavior and attitudes. The R+ subtype at age 10 was a risk factor for binge-eating but not obesity at ages 12 and 14.

DISCUSSION

Dietary restraint and depressive symptoms combined predict binge-eating longitudinally in a diverse community sample of girls.