33 research outputs found

    Weight regain and mental health outcomes following behavioural weight management programmes: a systematic review with meta‐analyses

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    Behavioural weight management programmes (BWMPs) lead to weight loss but subsequent weight regain may harm mental health outcomes. We searched for randomised trials of BWMPs in adults with overweight/obesity with follow-up ≄12 months from baseline that measured weight change both at and after programme-end. We included only studies reporting mental health at or after programme-end. We meta-analysed changes in various mental health outcomes using a random-effects model by nature of the comparator group and by time since programme end. Subgroup analysis explored heterogeneity. We used mixed models and meta-regression to analyse the association between change in weight and change in depression and/or anxiety over time, with higher scores indicating greater depression and/or anxiety. We included 47 studies. When comparing BWMPs (diet and/or exercise) to control, most estimates included the possibility of no difference, but pooled estimates for psychological wellbeing, self-esteem and mental-health composite scores at programme-end, anxiety at 1–6 months, and depression at 7–12 months after programme-end suggested improvements in intervention arms relative to control, with 95% CIs excluding no difference. Pooled estimates found no evidence that BWMPs harmed mental health at programme end or beyond. Mental health composite scores at programme-end favoured diet and exercise interventions over diet alone, with 95% CIs excluding no difference. All other measures and timepoints included the possibility of no difference or could not be meta-analysed due to high heterogeneity or a paucity of data. Mixed models and meta-regression of the association between change in depression and/or anxiety scores over time, and change in weight, were inconclusive. Despite weight regain after BWMPs, our meta-analyses found no evidence of mental health harm and some evidence that BWMPs may improve some dimensions of mental health at and after programme-end

    Weight regain after behavioural weight management programmes and its impact on quality of life and cost effectiveness: evidence synthesis and health economic analyses

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    Aims We used data from a recent systematic review to investigate weight regain after behavioural weight management programmes (BWMPs, sometimes referred to as lifestyle modification programmes) and its impact on quality-of-life and cost-effectiveness. Materials and Methods Trial registries, databases and forward-citation searching (latest search December 2019) were used to identify randomized trials of BWMPs in adults with overweight/obesity reporting outcomes at ≄12 months, and after programme end. Two independent reviewers screened records. One reviewer extracted data and a second checked them. The differences between intervention and control groups were synthesized using mixed-effect, meta-regression and time-to-event models. We examined associations between weight difference and difference in quality-of-life. Cost-effectiveness was estimated from a health sector perspective. Results In total, 155 trials (n > 150 000) contributed to analyses. The longest follow-up was 23 years post-programme. At programme end, intervention groups achieved –2.8 kg (95%CI –3.2 to –2.4) greater weight loss than controls. Weight regain after programme end was 0.12-0.32 kg/year greater in intervention relative to control groups, with a between-group difference evident for at least 5 years. Quality-of-life increased in intervention groups relative to control at programme end and thereafter returned to control as the difference in weight between groups diminished. BWMPs with this initial weight loss and subsequent regain would be cost-effective if delivered for under ÂŁ560 (ÂŁ8.80-ÂŁ3900) per person. Conclusions Modest rates of weight regain, with persistent benefits for several years, should encourage health care practitioners and policymakers to offer obesity treatments that cost less than our suggested thresholds as a cost-effective intervention to improve long-term weight management

    Stellar structure and compact objects before 1940: Towards relativistic astrophysics

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    Since the mid-1920s, different strands of research used stars as "physics laboratories" for investigating the nature of matter under extreme densities and pressures, impossible to realize on Earth. To trace this process this paper is following the evolution of the concept of a dense core in stars, which was important both for an understanding of stellar evolution and as a testing ground for the fast-evolving field of nuclear physics. In spite of the divide between physicists and astrophysicists, some key actors working in the cross-fertilized soil of overlapping but different scientific cultures formulated models and tentative theories that gradually evolved into more realistic and structured astrophysical objects. These investigations culminated in the first contact with general relativity in 1939, when J. Robert Oppenheimer and his students George Volkoff and Hartland Snyder systematically applied the theory to the dense core of a collapsing neutron star. This pioneering application of Einstein's theory to an astrophysical compact object can be regarded as a milestone in the path eventually leading to the emergence of relativistic astrophysics in the early 1960s.Comment: 83 pages, 4 figures, submitted to the European Physical Journal

    Supermassive Binaries and Extragalactic Jets

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    Some quasars show Doppler shifted broad emission line peaks. I give new statistics of the occurrence of these peaks and show that, while the most spectacular cases are in quasars with strong radio jets inclined to the line of sight, they are also almost as common in radio-quiet quasars. Theories of the origin of the peaks are reviewed and it is argued that the displaced peaks are most likely produced by the supermassive binary model. The separations of the peaks in the 3C 390.3-type objects are consistent with orientation-dependent "unified models" of quasar activity. If the supermassive binary model is correct, all members of "the jet set" (astrophysical objects showing jets) could be binaries.Comment: 31 pages, PostScript, missing figure is in ApJ 464, L105 (see http://www.aas.org/ApJ/v464n2/5736/5736.html

    Pattern and process in Norwegian upland grasslands: a functional analysis

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    Four classes of functional and morphological plant traits (FMT) – established strategies (the CSR scheme sensu Grime 1979), life-forms (sensu Raunkiaer 1934), morphology, and regenerative strategies – are used as tools for explaining vegetation gradients at summer farms in the mountains of western Norway. These farms are assembly points for free-ranging domestic grazers, and differ floristically and ecologically from the surrounding heath or woodland vegetation. Detrended Correspondence Analysis and Two-Way INdicator SPecies ANalysis are used to relate major gradients in a floristic data set from 12 summer farms to two sets of explanatory variables: (1) environmental variables representing physical factors, plot position, soils, and land-use, and (2) the four FMT classification schemes. The main floristic gradient parallels a spatial gradient from the centres of the farms to the surrounding vegetation. A functional interpretation based on the concurrent use of the two sets of explanatory variables suggests that the gradient is one of decreasing disturbance and increasing environmental stress caused by decreasing grazing and manure effects away from farms. Partial Canonical Correspondence Analysis is used to investigate the relationships between the four FMT classes. The four classification schemes are partially redundant, and do not represent different trends of specialisation within the landscape. There is no strong evidence for decoupling of the traits of the vegetative and regenerative phases within the data. The combination of general process-based theories and specific plant attribute responses enhances the generality and interpretability of the study
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