Background: Ample evidence attests to the relationship between short sleep duration, sleep problems and childhood obesity. However, few studies have examined the association between sleep timing and obesity in children. Objectives: To investigate how sleep duration, problems and timing relate to obesity and obesogenic behaviours in children. Methods: Eighty-five children (58.8% girls) with severe obesity and mean (SD) age of 12.1 (2.9) years, were matched by age and sex with peers with normal weight (n = 85,12.0 [2.8] years). Sleep and moderate-to-vigorous physical activity (MVPA) were measured via accelerometer for seven consecutive days. Children self-reported emotional eating on the Dutch eating behavior questionnaire. Parents reported children's screen time and sleep problems. Results: Children with severe obesity had significantly later mean mid-sleep time, overall (36 minutes later, P < .001), on school nights (36 minutes later, P < .001) and weekend nights (39 minutes later, P = .002) compared to children with normal weight. Children with obesity had more sleep problems (P = .030), but no differences emerged in sleep duration or social jetlag. After adjusting for demographic factors, mid-sleep time was positively related to screen time (P = .030). Mid-sleep time and sleep duration were inversely related to time in MVPA (Ps ≤ .041). There were no other significant associations between the sleep variables and the obesogenic behaviours. Conclusions: Later sleep timing was related to obesogenic behaviours in children and may represent an obesity risk factor.

BackgroundThe purpose of the FABO-study is to evaluate the effect of family-based behavioral social facilitation treatment (FBSFT), designed to target children’s family and social support networks to enhance weight loss outcomes, compared to the standard treatment (treatment as usual, TAU) given to children and adolescents with obesity in a routine clinical practice.MethodsRandomized controlled trial (RCT), in which families (n = 120) are recruited from the children and adolescents (ages 6–18 years) referred to the Obesity Outpatient Clinic (OOC), Haukeland University Hospital, Norway. Criteria for admission to the OOC are BMI above the International Obesity Task Force (IOTF) cut-off ≥ 35, or IOTF ≥ 30 with obesity related co-morbidity. Families are randomized to receive FBSFT immediately or following one year of TAU. All participants receive a multidisciplinary assessment. For TAU this assessment results in a plan and a contract for chancing specific lifestyle behaviors. Thereafter each family participates in monthly counselling sessions with their primary health care nurse to work on implementing these goals, including measuring their weight change, and also meet every third month for sessions at the OOC. In FBSFT, following assessment, families participate in 17 weekly sessions at the OOC, in which each family works on changing lifestyle behaviors using a structured cognitive-behavioral, socio-ecological approach targeting both parents and children with strategies for behavioral maintenance and sustainable weight change.Outcome variables include body mass index (BMI; kg/m2), BMI standard deviation score (SDS) and percentage above the IOTF definition of overweight, waist-circumference, body composition (bioelectric impedance (BIA) and dual-X-ray-absorptiometry (DXA)), blood tests, blood pressure, activity/inactivity and sleep pattern (measured by accelerometer), as well as questionnaires measuring depression, general psychological symptomatology, self-esteem, disturbed eating and eating disorder symptoms. Finally, barriers to treatment and parenting styles are measured via questionnaires.DiscussionThis is the first systematic application of FBSFT in the treatment of obesity among youth in Norway. The study gives an opportunity to evaluate the effect of FBSFT implemented in routine clinical practice across a range of youth with severe obesity.Trial registrationClinicalTrails.gov NCT02687516. Registered 16th of February, 2016Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-016-3755-9) contains supplementary material, which is available to authorized users.

To compare the effectiveness of family-based behavioural social facilitation treatment (FBSFT) versus treatment as usual (TAU) in children with severe obesity. Parallel-design, nonblinded, randomized controlled trial conducted at a Norwegian obesity outpatient clinic. Children aged 6-18 years referred to the clinic between 2014 and 2018 were invited to participate. Participants were randomly allocated using sequentially numbered, opaqued, sealed envelopes. FBSFT (n = 59) entailed 17 sessions of structured cognitive behavioural treatment, TAU (n = 55) entailed standard lifestyle counselling sessions every third month for 1 year. Primary outcomes included changes in body mass index standard deviation score (BMI SDS) and percentage above the International Obesity Task Force cut-off for overweight (%IOTF-25). Secondary outcomes included changes in sleep, physical activity, andeating behaviour. From pre-to posttreatment there was a statistically significant difference in change in both BMI SDS (0.19 units, 95% confidence interval [CI]: 0.10-0.28, p < .001) and p < .001) between FBSFT and TAU groups. FBSFT participants achieved significant reductions in mean BMI SDS (0.16 units, (95%CI: À0.22 to À0.10, p < .001) and %IOTF-25 (6.53%, 95% CI: À8.45 to À4.60, p < .001), whereas in TAU nonsignificant changes were observed in BMI SDS (0.03 units, 95% CI: À0.03 to 0.09, p = .30) and %IOTF-25 (À1.04%, 95% CI: À2.99 to À0.90, p = .29). More FBSFT participants (31.5%) had clinically meaningful BMI SDS reductions of ≥0.25 from pre-to posttreatment than in TAU (13.0%, p = .021). Regarding secondary outcomes, only changes in sleep timing differed significantly between groups. FBSFT improved weight-related outcomes compared to TAU. Yngvild S. Danielsen and Petur B. Juliusson are joint senior authors.

Aim: Body mass index (BMI) metrics are widely used as a proxy for adiposity in children with severe obesity. The BMI expressed as the percentage of a cut-off percentile for overweight or obesity has been proposed as a better alternative than BMI z-scores when monitoring children and adolescents with severe obesity.Methods: Annual changes in BMI, BMI z-score and the percentage above the International Obesity Task Force overweight cut-off (%IOTF-25) were compared with dual-energy X-ray absorptiometry (DXA) derived body fat (%BF-DXA) in 59 children and adolescents with severe obesity.Results: The change in %BF-DXA was correlated with the change in %IOTF-25 (r = 0.68) and BMI (r = 0.70), and somewhat less with the BMI z-score (r = 0.57). Cohen's Kappa statistic to detect an increase or decrease in %BF-DXA was fair for %IOTF-25 (j = 0.25; p = 0.04) and BMI (j = 0.33; p = 0.01), but not for the BMI z-score (j = 0.08; p = 0.5). The change in BMI was positively biased due to a natural increase with age. Conclusion: Changes in the BMI metrics included in the study are associated differentlyAbbreviations %BF, Percentage body fat; %IOTF-25, Percentage above the International Obesity Task Force definition of overweight; BMI, Body mass index; DXA, Dual-energy X-ray absorptiometry. Key notesThe percentage above the International Obesity Task Force overweight cut-off (%IOTF-25) has been suggested as an unbiased alternative with respect to age for the body mass index (BMI) or BMI z-score in children and adolescents with severe obesity. Changes in BMI, BMI z-scores and %IOTF-25 were compared with dual-energy x-ray absorptiometry of body composition. The %IOTF-25 might be a better alternative to BMI z-scores to monitor changes in adiposity.

Short sleep and obstructive apneas/hypopneas have been shown to be associated with childhood obesity. Still, few studies have compared sleep in children with obesity, without suspected sleep disordered breathing and normal weight peers by objective sleep measures and compared results with subjective parent assessment of sleep. Children with obesity aged 7-13 years (N = 44) and a matched group of normal weight children (N = 42) completed clinical polysomnography (Embla A10 Recording System). Parents scored their children's sleep on the Children's Sleep Habits Questionnaire (CSHQ). Mann-Whitney U tests were used to compare groups. There was a higher obstructive apnea/hypopnea index (AHI) (median obesity = 1.20 vs. median normal = 0.66; z = À1.33, U = 560.50, p = 0.002) and number of oxygen desaturation events per hour (median obesity = 0.7 vs. median normal = 0.2; z = À3.45, U = 402.50, p = 0.001) in the children with obesity compared to children with normal weight. The children with obesity had a significantly longer sleep duration (median obesity 8:50 h = vs. median normal = 8:32 h; z = À2.05, U = 687.00, p = 0.041), longer stage N2 sleep (median obesity = 87 min vs. median normal = 52 min; z = À2.87, U = 576.50, p = 0. 004) and shorter REM sleep (median obesity = 94 min vs. median normal = 121 min; z = 5.05, U = 1477.00, p ≤ .001). No differences were observed for time in sleep stage N1 and N3, wake time after sleep onset or the total arousal index . Further, no group differences were found on the CSHQ sleep-disordered breathing sub-scale (p = 0.399). The children with obesity demonstrated significantly more mild to moderate sleep disordered breathing than children with normal weight, although this was not corroborated by parent report.