Erica Y. Lau

Maternal Weight Gain in Pregnancy and Risk of Obesity among Offspring: A Systematic Review

Objectives. To systematically review the evidence from prospective and retrospective cohort studies on the association between gestational weight gain (GWG) and offsprings body weight. Methods. Electronic databases PubMed, Web of Science, CINAHL, and Academic Search Premiere were searched from inception through March 18, 2013. Included studies (n = 23) were English articles that examined the independent associations of GWG with body mass index (BMI) and/or overweight status in the offspring aged 2 to 18.9 years. Two authors independently extracted the data and assessed methodological quality of the included studies. Results. Evidence from cohort studies supports that total GWG and exceeding the Institute of Medicine maternal weight gain recommendation were associated with higher BMI z-score and elevated risk of overweight or obesity in offspring. The evidence of high rate of GWG during early- and mid-pregnancy is suggestive. Additionally, the evidence on inadequate GWG and net GWG in relation to body weight outcomes in offspring is insufficient to draw conclusions. Conclusions. These findings suggest that GWG is a potential risk factor for childhood obesity. However, findings should be interpreted with caution due to measurement issues of GWG and potential confounding effects of shared familial characteristics (i.e., genetics and maternal and childs lifestyle factors).

Validation of a Novel Protocol for Calculating Estimated Energy Requirements and Average Daily Physical Activity Ratio for the US Population: 2005-2006

OBJECTIVE To validate the PAR protocol, a novel method for calculating population-level estimated energy requirements (EERs) and average physical activity ratio (APAR), in a nationally representative sample of US adults. METHODS Estimates of EER and APAR values were calculated via a factorial equation from a nationally representative sample of 2597 adults aged 20 and 74 years (US National Health and Nutrition Examination Survey; data collected between January 1, 2005, and December 31, 2006). Validation of the PAR protocol-derived EER (EER(PAR)) values was performed via comparison with values from the Institute of Medicine EER equations (EER(IOM)). RESULTS The correlation between EER(PAR) and EER(IOM) was high (0.98; P<.001). The difference between EER(PAR) and EER(IOM) values ranged from 40 kcal/d (1.2% higher than EER(IOM)) in obese (body mass index [BMI] ≥30) men to 148 kcal/d (5.7% higher) in obese women. The 2005-2006 EERs for the US population were 2940 kcal/d for men and 2275 kcal/d for women and ranged from 3230 kcal/d in obese (BMI ≥30) men to 2026 kcal/d in normal weight (BMI <25) women. There were significant inverse relationships between APAR and both obesity and age. For men and women, the APAR values were 1.53 and 1.52, respectively. Obese men and women had lower APAR values than normal weight individuals (P¼.023 and P¼.015, respectively) [corrected], and younger individuals had higher APAR values than older individuals (P<.001). CONCLUSION The PAR protocol is an accurate method for deriving nationally representative estimates of EER and APAR values. These descriptive data provide novel quantitative baseline values for future investigations into associations of physical activity and health.

Does dose matter in reducing gestational weight gain in exercise interventions? A systematic review of literature

OBJECTIVES The purpose of this review was to examine the relationship between exercise dose and reductions in weight gain during pregnancy in exercise interventions. DESIGN Systematic literature review. METHODS Four electronic research databases (PubMed, Web of Science, CINAHL, and Academic Search Premiere) were used to identify exercise interventions conducted with pregnant women. Eligible articles must have satisfied the following criteria: inclusion of a control condition, exercise as a major intervention component, weight gain measured and reported for each experimental condition, description of exercise dose (frequency, intensity and duration), and utilized an adequate number of control conditions to assess independent effects of exercise on weight gain. RESULTS The literature search identified 4837 articles. Of these, 174 abstracts were screened and 21 intervention studies (18 exercise-only, 3 exercise/diet) were eligible for review. Only 38% of the interventions achieved statistically significant reductions in gestational weight gain. Successful interventions possessed higher adherence and lower attrition rates and were predominantly conducted among normal weight populations. No clear patterns or consistencies of exercise dose and reductions in weight gain were evident. CONCLUSIONS An exercise dose associated with reductions in weight gain was unquantifiable among these interventions. Adherence and retention rates were strong contributors to the success of exercise interventions on gestational weight gain. It is strongly suggested that future researchers investigate methods to increase adherence and compliance, especially among overweight and obese women, and utilize objective measurement tools to accurately evaluate exercise dose performed by the participants and the impact on body composition and weight gain.

Evaluation of an Internet-Short Message Service-Based Intervention for Promoting Physical Activity in Hong Kong Chinese Adolescent School Children: A Pilot Study

Evaluation of acceptability and preliminary efficacy of an Internet and short message service (SMS) intervention for promoting physical activity (PA) in Hong Kong Chinese school children. An 8-week quasi-experimental study non-randomly assigned 78 school children (mean age=12.8 years) to (a) an intervention group that received a stage-matched, Internet PA program two times a week and tailored SMS messages daily; or (b) a no-treatment control. Data were collected from September 2008 until June 2009. Acceptability measures included exposure rate and participants satisfaction. Efficacy measures were changes in stage of motivational readiness (SMR) and self-reported PA level. Intervention participants demonstrated significant pre-post increments in SMR (Z=-2.558, p=0.011) and self-reported PA level [F(1, 76)=4.50, p=0.04]. There was a non-significant trend between groups in both SMR (p=0.24) and PA (p=0.13). Despite the similar ratings of satisfaction between Internet (M=3.12±0.74) and SMS (M=3.12±0.84), participants displayed distinct patterns of exposure with 66% exhibiting a weekly login rate of 0.5 times/person and an average of 3.75 minutes/visit/person. In contrast, 79% of participants read an average of 1.3 SMS/person/week and 47% voluntarily replied to ∼3.8 SMS/person. These findings demonstrate the acceptability and preliminary efficacy of an Internet-SMS-based intervention for promoting PA in Hong Kong school children. The divergent exposure rates between the Internet and SMS may be a unique pattern for adolescents in early SMR. Future research should be cognizant of the importance of SMR since it may influence utilization and/or adherence.

Evaluating physical and perceptual responses to exergames in Chinese children.

Purpose: The primary objective of this study was to examine whether exergames could help children reach the recommendations for PA and cardiorespiratory fitness regarding exercise intensity. Differences in perceived physical exertion, EE, VO2, and HR between normal weight (NW) and overweight (OW) children participating in exergames were also examined. Methods: Twenty-one children (age: 10.45 ± 0.88) were assessed for EE, VO2 and HR during rest, in a maximal treadmill test, and while playing different exergames. Ratings of perceived exertion (RPE) (category range: 0 to 10) were also measured during exergaming. Three types of exergames were examined: running, table tennis, and dancing. These games were either performed on a Chinese game console, I-Dong, or another well-developed Western game console (Sony PlayStation 3 or Nintendo Wii). Results: Exergaming resulted in EE (kcal/min) from 2.05–5.14, VO2 (mL/kg/min) from 9.98–25.54, and HR (beats per minute) from 98.05–149.66. Children reported RPE ranging from 1.29 to 5.29. The Chinese exergame, I-Dong Running, was the only game in which children reached a moderate intensity and met the recommended minimum VO2reserve (50%) for cardiorespiratory fitness. Conclusion: Exergames could provide alternative opportunities to enhance children’s physical activity. They could be used as light-to-moderate PA, and with exergames, children can even reach the recommended intensity for developing and maintaining cardiorespiratory fitness.

The Effects of Text Message Content on the Use of an Internet-Based Physical Activity Intervention in Hong Kong Chinese Adolescents

This study examined the effects of text message content (generic vs. culturally tailored) on the login rate of an Internet physical activity program in Hong Kong Chinese adolescent school children. A convenience sample of 252 Hong Kong secondary school adolescents (51% female, 49% male; M age = 13.17 years, SD = 1.28 years) were assigned to one of 3 treatments for 8 weeks. The control group consisted of an Internet physical activity program. The Internet plus generic text message group consisted of the same Internet physical activity program and included daily generic text messages. The Internet plus culturally tailored text message group consisted of the Internet physical activity program and included daily culturally tailored text messages. Zero-inflated Poisson mixed models showed that the overall effect of the treatment group on the login rates varied significantly across individuals. The login rates over time were significantly higher in the Internet plus culturally tailored text message group than the control group (β = 46.06, 95% CI 13.60, 156.02; p = .002) and the Internet plus generic text message group (β = 15.80, 95% CI 4.81, 51.9; p = .021) after adjusting for covariates. These findings suggest that culturally tailored text messages may be more advantageous than generic text messages on improving adolescents’ website login rate, but effects varied significantly across individuals. Our results support the inclusion of culturally tailored messaging in future online physical activity interventions.