Objective To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement among adults who are overweight or obese. Design Systematic review and network meta-analysis of randomised trials. Data sources Medline, Embase, CINAHL, AMED, and CENTRAL from database inception until September 2018, reference lists of eligible trials, and related reviews. Study selection Randomised trials that enrolled adults (≥18 years) who were overweight (body mass index 25-29) or obese (≥30) to a popular named diet or an alternative diet. Outcomes and measures Change in body weight, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, systolic blood pressure, diastolic blood pressure, and C reactive protein at the six and 12 month follow-up. Review methods Two reviewers independently extracted data on study participants, interventions, and outcomes and assessed risk of bias, and the certainty of evidence using the GRADE (grading of recommendations, assessment, development, and evaluation) approach. A bayesian framework informed a series of random effects network meta-analyses to estimate the relative effectiveness of the diets. Results 121 eligible trials with 21 942 patients were included and reported on 14 named diets and three control diets. Compared with usual diet, low carbohydrate and low fat diets had a similar effect at six months on weight loss (4.63 v 4.37 kg, both moderate certainty) and reduction in systolic blood pressure (5.14 mm Hg, moderate certainty v 5.05 mm Hg, low certainty) and diastolic blood pressure (3.21 v 2.85 mm Hg, both low certainty). Moderate macronutrient diets resulted in slightly less weight loss and blood pressure reductions. Low carbohydrate diets had less effect than low fat diets and moderate macronutrient diets on reduction in LDL cholesterol (1.01 mg/dL, low certainty v 7.08 mg/dL, moderate certainty v 5.22 mg/dL, moderate certainty, respectively) but an increase in HDL cholesterol (2.31 mg/dL, low certainty), whereas low fat (−1.88 mg/dL, moderate certainty) and moderate macronutrient (−0.89 mg/dL, moderate certainty) did not. Among popular named diets, those with the largest effect on weight reduction and blood pressure in comparison with usual diet were Atkins (weight 5.5 kg, systolic blood pressure 5.1 mm Hg, diastolic blood pressure 3.3 mm Hg), DASH (3.6 kg, 4.7 mm Hg, 2.9 mm Hg, respectively), and Zone (4.1 kg, 3.5 mm Hg, 2.3 mm Hg, respectively) at six months (all moderate certainty). No diets significantly improved levels of HDL cholesterol or C reactive protein at six months. Overall, weight loss diminished at 12 months among all macronutrient patterns and popular named diets, while the benefits for cardiovascular risk factors of all interventions, except the Mediterranean diet, essentially disappeared. Conclusions Moderate certainty evidence shows that most macronutrient diets, over six months, result in modest weight loss and substantial improvements in cardiovascular risk factors, particularly blood pressure. At 12 months the effects on weight reduction and improvements in cardiovascular risk factors largely disappear. Systematic review registration PROSPERO CRD42015027929.

We conducted a scoping review to identify definitions of metabolically healthy obesity (MHO), describe gaps in the literature, and establish a universal definition of MHO in children. We searched electronic databases from January 1980 to June 2017 and grey literature. Experimental, quasi-experimental, or observational studies were eligible for inclusion if they (i) included a definition of MHO that identified risk factors, cut-off values, and the number of criteria used to define MHO, and (ii) classified 2-18 year olds as overweight or obese. Two reviewers independently screened 1,711 papers for relevance and quality; we extracted data from 39 individual reports that met inclusion criteria. Most (31/39; 79%) definitions of MHO included an absence of cardiometabolic risk factors. Heterogeneity across MHO definitions, obesity criteria, and sample sizes/characteristics resulted in variable prevalence estimates (3-80%). Finally, we convened an international panel of 46 experts to complete a 4-round Delphi process to generate a consensus-based definition of MHO. Based on consensus (≥ 80% agreement), our definition of MHO included: high density lipoprotein-cholesterol > 40 mg/dl (or > 1.03 mmol/l), triglycerides ≤ 150 mg/dl (or ≤ 1.7 mmol/l), systolic and diastolic blood pressure ≤ 90th percentile, and a measure of glycemia. This definition of MHO holds potential universal value to enable comparisons between studies and inform clinical decision-making for children with obesity.

Healthy lifestyle behaviours are key to successful weight management, but have proven to be challenging to attain for adolescents with obesity. The purpose of our scoping review was to (i) describe barriers and enablers that adolescents with obesity encounter for healthy nutrition, physical activity, sedentary behaviour and sleep habits and (ii) identify gaps in the literature. We adhered to established methodology for scoping reviews. Six databases were searched (1980-June 2016) for original articles published in English or French that focused on lifestyle behaviours of 13- to 17-year-olds in paediatric weight management. Following screening and data extraction, findings of selected articles were synthesized thematically using a social ecological framework. Stakeholder consultation (n = 20) with adolescents with obesity and health professionals was completed to enhance methodological rigour. Our search yielded 17 articles for inclusion, including 546 unique participants. Barriers to healthy nutrition and physical activity were more consistently related to individual-level and interpersonal-level factors; enablers tended to be linked with interpersonal-level factors. Knowledge gaps identified related to sedentary behaviour and sleep as well as environmental and policy levels of influence. Our review revealed that some barriers and enablers were unique to adolescents with obesity, which were either within or beyond their control. These findings highlight the importance of multilevel interventions to enable healthy lifestyle behaviours for weight management.

BackgroundOver recent decades, the prevalence of pediatric obesity has increased markedly in developed and developing countries, and the impact of obesity on health throughout the lifespan has led to urgent calls for action. Family-based weight management interventions that emphasize healthy lifestyle changes can lead to modest improvements in weight status of children with obesity. However, these interventions are generally short in duration, reported in the context of randomized controlled trials and there are few reports of outcomes of these treatment approaches in the clinical setting. Answering these questions is critical for improving the care of children with obesity accessing outpatient health services for weight management. In response, the CANadian Pediatric Weight management Registry (CANPWR) was designed with the following three primary aims:1. Document changes in anthropometric, lifestyle, behavioural, and obesity-related co-morbidities in children enrolled in Canadian pediatric weight management programs over a three-year period;2. Characterize the individual-, family-, and program-level determinants of change in anthropometric and obesity-related co-morbidities;3. Examine the individual-, family-, and program-level determinants of program attrition.Methods/DesignThis prospective cohort, multi-centre study will include children (2–17 years old; body mass index ≥85th percentile) enrolled in one of eight Canadian pediatric weight management centres. We will recruit 1,600 study participants over a three-year period. Data collection will occur at presentation and 6-, 12-, 24-, and 36-months follow-up. The primary study outcomes are BMI z-score and change in BMI z-score over time. Secondary outcomes include anthropometric (e.g., height, waist circumference,), cardiometabolic (e.g., blood pressure, lipid profile, glycemia), lifestyle (e.g., dietary intake, physical activity, sedentary activity), and psychosocial (e.g., health-related quality of life) variables. Potential determinants of change and program attrition will include individual-, family-, and program-level variables.DiscussionThis study will enable our interdisciplinary team of clinicians, researchers, and trainees to address foundational issues regarding the management of pediatric obesity in Canada. It will also serve as a harmonized, evidence-based registry and platform for conducting future intervention research, which will ultimately enhance the weight management care provided to children with obesity and their families.