Katya M. Herman, Catherine M. Sabiston, Angelo Tremblay and Gilles Paradis
Self-rated health (SRH) is a common indicator of health-related quality of life; however, little is known about SRH in children. This study explored the associations of physical activity (PA), sedentary behavior (SED), and BMI with SRH in children at risk for obesity.
Participants were 527 children aged 8–10 years in the Quebec Adipose and Lifestyle Investigation in Youth study (inclusion criteria: ≥ 1 parent clinically obese). PA and SED were measured by accelerometer, specific SED behaviors by self-report, and height and weight measured.
About 40% of children were overweight or obese; 48% reported lessthan- excellent health. The odds of reporting less-than-excellent health were higher among obese girls (OR 3.0, 95% CI 1.4–5.2) and boys (OR 2.7, 95% CI 1.5–6.1) versus healthy weight children. Boys not meeting PA guidelines and boys in the lowest moderate-to-vigorous PA tertile were at 2 and 6 times higher odds of less-than-excellent SRH, respectively, versus more active boys. In girls, higher computer/video time and reading time were associated with higher and lower odds of less-than-excellent SRH, respectively.
Obesity is inversely associated with SRH in boys and girls, PA is positively associated with SRH in boys, and SED behaviors are associated with SRH in girls.
Georges Jabbour, Melanie Henderson, Angelo Tremblay and Marie Eve Mathieu
Moderate-to-vigorous physical activity (MVPA) improves aerobic fitness in children, which is usually assessed by maximal oxygen consumption. However, other indices of aerobic fitness have been understudied.
To compare net oxygen (VO2net), net energy consumption (Enet), net mechanical efficiency (MEnet), and lipid oxidation rate in active and inactive children across body weight statuses.
The sample included normal-weight, overweight, and obese children of whom 44 are active (≥30 min of MVPA/d) and 41 are inactive (<30 min of MVPA/d). VO2net, Enet, MEnet and lipid oxidation rate were determined during an incremental maximal cycling test.
Active obese participants had significantly lower values of VO2net and Enet and higher MEnet than inactive obese participants at all load stages. In addition, active obese participants showed a significantly higher lipid oxidation rate compared with inactive obese and active overweight and normal-weight participants. VO2net, Enet, and MEnet were similar across active children, regardless of body weight status.
Thirty minutes or more of MVPA per day is associated with a potentiation of aerobic fitness indicators in obese prepubertal children. Moreover, the indices of aerobic fitness of inactive obese children are significantly different from those of active obese and nonobese ones.
Katya M. Herman, Jean-Philippe Chaput, Catherine M. Sabiston, Marie-Eve Mathieu, Angelo Tremblay and Gilles Paradis
Individuals may achieve high physical activity (PA) yet also be highly sedentary (SED). This study assessed adiposity in children classified by PA/SED groups.
Participants were 520 8- to 10-year-old children with ≥ 1 obese parent. Moderate-to-vigorous PA (MVPA) and SED were measured by accelerometer, and screen-time was measured by self-report. Height, weight, waist circumference (WC), body fat percentage (BF%), and VO2peak were objectively measured; energy intake was measured by dietary recall. Elevated adiposity was defined as BMI ≥ 85th percentile, WC ≥ 90th percentile, BF% ≥ 85th percentile, or waist-to-height ratio (WHR) ≥ 0.5.
Up to 27% of boys and 15% of girls were active/SED. Adiposity was lowest for active/non-SED, highest for inactive/SED, and intermediate and similar for active/SED and inactive/non-SED. Using 60 min/d MVPA and 2 h/d screen-time cut-offs, prevalence ranges for elevated adiposity in the active/non-SED, active/SED, inactive/non-SED, and inactive/SED groups were 0% to 14%, 15% to 44%, 16% to 40%, and 32% to 51%, respectively. Corresponding odds and 95% confidence intervals of being overweight/obese for the latter groups were 3.8 (95% CI, 1.7−8.4), 3.8 (1.8−8.2), and 4.9 (2.3−10.3) versus active/non-SED. PA/SED-adiposity associations were mediated by fitness but not energy intake.
Combined PA/SED levels are strongly associated with adiposity in children, but associations are mediated by fitness. Active children who accumulate >2 h/d of screen time and inactive children are equally likely to be overweight/obese.
Pauline M. Genin, Frédéric Dutheil, Benjamin Larras, Yoland Esquirol, Yves Boirie, Angelo Tremblay, Bruno Pereira, Corinne Praznoczy, David Thivel and Martine Duclos