Non-surgical Weight Loss Interventions Research Articles

Gut-muscle communication links FGF19 levels to the loss of lean muscle mass following rapid weight loss

ObjectiveOptimal weight loss involves decreasing adipose tissue while preserving lean muscle mass. Identifying molecular mediators that preserve lean muscle mass is therefore a clinically important goal. We have shown that circulating, postprandial FGF19 levels are lower in patients with obesity and decrease further with comorbidities such as type 2 diabetes and MASLD. Preclinical studies have shown that FGF15 (mouse ortholog of human FGF19) is necessary to protect against lean muscle mass loss following metabolic surgery-induced weight loss in a mouse model of diet-induced obesity. We evaluated if non-surgical weight loss interventions also lead to increased systemic levels of FGF19 and whether FGF19 levels are predictive of lean muscle mass following rapid weight loss in human subjects with obesity. Research design and methodsWeight loss was induced in 176 subjects with obesity via a very low-energy diet, VLED (800 kcal/d) in the form of total liquid meal replacement for 3-4 months. We measured plasma FGF19 levels at baseline and following VLED-induced weight loss. Multiple linear regression was performed to assess if FGF19 levels were predictive of lean mass at baseline (obesity) and following VLED. ResultsPostprandial levels of FGF19 increased significantly following VLED-weight loss. Multiple linear regression analysis showed that baseline (obesity) FGF19 levels, but not post VLED FGF19 levels, significantly predicted the percent of lean muscle mass after VLED-induced weight loss, while controlling for age, sex, and the baseline percent lean mass. ConclusionThese data identify gut-muscle communication and FGF19 as a potentially important mediator of the preservation of lean muscle mass during rapid weight loss.

A systematic review of the economic value proposition for commercially available nonsurgical weight-loss interventions.

The study aim was to review the economic evaluation literature of commercially available and effective nonsurgical weight-loss interventions to investigate whether there is evidence to support claims of cost-effectiveness (i.e., good value for money) or cost savings (i.e., a positive return on investment). Relevant databases were systematically reviewed to identify economic evaluations of commercially available weight-loss products and services shown to result in clinically significant weight loss. Five weight-loss medications (orlistat, liraglutide, naltrexone-bupropion, semaglutide, and phentermine-topiramate), two meal replacement programs (Jenny Craig, Optifast), and one behavioral intervention (Weight Watchers [WW]) that met inclusion criteria were identified. After screening, 32 relevant comparisons of cost-effectiveness or cost savings across 20 studies were identified. Ten of twenty pharmaceutical comparisons showed evidence of cost-effectiveness based on established thresholds. Four of twelve nonpharmaceutical comparisons provided evidence of cost-effectiveness, and five made claims of cost savings. However, methodological concerns cast doubt on the robustness of these claims. Evidence of cost-effectiveness for commercially available, evidence-based, nonsurgical weight-loss interventions is mixed. There is no evidence for cost-saving weight-loss medications and only weak evidence for behavioral and weight-loss interventions. Results provide a call to action to generate more robust evidence of the economic value proposition for these interventions.

Preoperative Optimization Before Ventral Hernia Repair: A Systematic Review and Meta-analysis.

Obesity is associated with an increased risk of ventral hernia development and recurrence rates after ventral hernia repair (VHR). The metabolic derangements caused by obesity can also lead to many postoperative complications. Therefore, it is a common practice to attempt weight loss before VHR. However, there is still no consensus on optimal preoperative management for obese patients with a ventral hernia. This study aims to perform a meta-analysis to evaluate the effect of preoperative weight optimization on VHR outcomes. We performed a literature search of PubMed, Scopus, and Cochrane Library databases to identify studies comparing obese patients who underwent surgical or non-surgical weight loss interventions before undergoing hernia repair surgery to obese patients who underwent hernia repair surgery without prehabilitation. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Statistical analysis was performed using RevMan 5.4. Heterogeneity was assessed with I2 statistics. One thousand six hundred nine studies were screened and 13 were thoroughly reviewed. Five studies comprising 465 patients undergoing hernia repair surgery were included. No differences in hernia recurrence [odds ratio (OR) 0.66; 95% CI 0.23-1.89; P=0.44; I2=20%], seroma (OR 0.70; 95% CI 0.25-1.95; P=0.50; I2=5%), hematoma (OR 2.00; 95% CI 0.5-7.94; P=0.45; I2=0%), surgical site infection (OR 1.96; 95% CI 0.52-7.40; P=0.32; I2=0%), and overall complication (OR 0.80; 95% CI 0.37-1.74; P=0.58; I2=40%) rates were noted when comparing patients who underwent a preoperative weight loss intervention (prehabilitation or bariatric surgery) versus those who did not. In the subgroup analysis of patients who underwent bariatric surgery, we found no difference in hernia recurrence (OR 0.64; 95% CI 0.12-3.33; P= 0.59; I2=41%) or overall complications (OR 1.14; 95% CI 0.36-3.64; P=0.82; I2=64%). In the subgroup analysis of patients who lost weight versus patients who did not, there was no significant difference in overall complication rates (OR 0.86; 95% CI 0.34-2.21; P=0.76; I2=55%). We found similar hernia recurrence, seroma, hematoma, and surgical site infection rates in patients who underwent preoperative optimization. These findings underline the need for prospective studies to define the optimal role of preoperative optimization and weight loss in obese patients undergoing ventral hernia repair.

Cost-Effectiveness of Weight-Loss Interventions Prior to Total Knee Replacement for Patients With Class III Obesity.

Class III obesity (body mass index >40 kg/m2 ) is associated with higher complications following total knee replacement (TKR), and weight loss is recommended. We aimed to establish the cost-effectiveness of Roux-en-Y gastric bypass (RYGB), laparoscopic sleeve gastrectomy (LSG), and lifestyle nonsurgical weight loss (LNSWL) interventions in knee osteoarthritis patients with class III obesity considering TKR. Using the Osteoarthritis Policy model and data from published literature to derive model inputs for RYGB, LSG, LNSWL, and TKR, we assessed the long-term clinical benefits, costs, and cost-effectiveness of weight-loss interventions for patients with class III obesity considering TKR. We assessed the following strategies with a health care sector perspective: 1) no weight loss/no TKR, 2) immediate TKR, 3) LNSWL, 4) LSG, and 5) RYGB. Each weight-loss strategy was followed by annual TKR reevaluation. Primary outcomes were cost, quality-adjusted life expectancy (QALE), and incremental cost-effectiveness ratios (ICERs), discounted at 3% per year. We conducted deterministic and probabilistic sensitivity analyses to examine the robustness of conclusions to input uncertainty. LSG increased QALE by 1.64 quality-adjusted life-years (QALYs) and lifetime medical costs by $17,347 compared to no intervention, leading to an ICER of $10,600/QALY. RYGB increased QALE by 0.22 and costs by $4,607 beyond LSG, resulting in an ICER of $20,500/QALY. Relative to immediate TKR, LSG and RYGB delayed and decreased TKR utilization. In the probabilistic sensitivity analysis, RYGB was cost-effective in 67% of iterations at a willingness-to-pay threshold of $50,000/QALY. For patients with class III obesity considering TKR, RYGB provides good value while immediate TKR without weight loss is not economically efficient.

Locus of control and self-efficacy in relation to 12-month weight change after non-surgical weight loss treatment in adults with severe obesity – A clinical cohort study

Sustainable dietary, behavioural and lifestyle changes are necessary to accomplish weight loss. Evaluate impact of internal motivation, locus of control and self-efficacy on non-surgical weight loss treatment in patients with severe obesity. A total of 1196 patients, Body Mass Index ≥35 kg/m 2 , referred to obesity treatment were included. Visual analogue scales for motivation, locus of control and self-efficacy were completed before starting weight loss treatment. A total of 601 patients (42% drop out) completed 12-month weight loss treatment. After 12 months, 94.6% in the Very Low Energy Diet (VLED) group and 79.4% in the dietary treatment group had a weight loss of ≥5% of their body weight. No statistically significant associations were found between achieved weight loss in the VLED group, and locus of control or self-efficacy. Achieving ≥15% weight loss by dietary treatment was related to a higher score on self-efficacy compared to those who lost <5% in weight or dropped out. Self-efficacy appears to be important for weight loss when on dietary treatment without VLED. Attrition rate was higher among patients with lower score on self-efficacy at baseline. The study indicates that psychological factors associated with adherence to, and completion of weight loss treatment deserve attention. • Locus of control and self-efficacy did not predict weight loss when treated with VLED. • Extensive weight loss early in treatment with VLED predicted completion of treatment. • Self-efficacy was positively correlated to weight loss in dietary treatment. • High level of self-efficacy predicted completion of dietary treatment. This knowledge is important when developing effective weight loss treatment in order to focus on effective strategies and behaviors framing outcome, as well as awareness of factors preventing successful weight loss and weight loss maintenance.

Nonsurgical weight loss interventions: A systematic review of systematic reviews and meta-analyses.

Access to bariatric surgery to treat obesity is limited and has long wait times. Many adults are seeking nonsurgical weight loss support. Our study objective was to conduct a systematic review of nonsurgical weight loss interventions. PubMed, EMBASE, CINAHL, PsycInfo, and the CochraneLibrary were searched. Inclusion criteria were adults 18 + with a BMI > 25 enrolled in minimum a 3-month nonsurgical weight loss intervention. Studies were independently extracted and assessed for quality using A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR2). Pooled analyses were extracted, graded for evidence quality, and summarized. A total of 1065 studies were assessed for eligibility; 815 screened and 236 full-texts assessed. Sixty-four meta-analyses met eligibility criteria: 1180 RCTs with 184,605 study participants. Studies were categorized as diets (n = 13), combination therapies (n = 10), alternative (n = 16), technology (n = 10), behavioral (n = 5), physical activity (n = 6), and pharmacotherapy (n = 3). In 80% of studies, significant weight losses were reported ranging from 0.34-8.73 k in favor of the intervention. The most effective nonsurgical weight loss interventions were diets, either low-carbohydrate or low-fat diets, followed for 6 months; combination therapy including meal replacements plus enhanced support; and pharmacotherapy followed for 12 months. Although significant weight losses were reported for other types of interventions such as physical activity and technology, the majority of studies reported weight losses less than 2 kgs.

Mechanisms of Weight Loss After Obesity Surgery.

Obesity surgery remains the most effective treatment for obesity and its complications. Weight loss was initially attributed to decreased energy absorption from the gut but has since been linked to reduced appetitive behavior and potentially increased energy expenditure. Implicated mechanisms associating rearrangement of the gastrointestinal tract with these metabolic outcomes include central appetite control, release of gut peptides, change in microbiota, and bile acids. However, the exact combination and timing of signals remain largely unknown. In this review, we survey recent research investigating these mechanisms, and seek to provide insights on unanswered questions over how weight loss is achieved following bariatric surgery which may eventually lead to safer, nonsurgical weight-loss interventions or combinations of medications with surgery.

Abstract 2576: Calorie restriction reverses the tumorigenic effects of obesity to a greater extent than bariatric surgery in a murine model of breast cancer

Abstract Obesity is an established risk and prognostic factor for multiple breast cancer (BC) subtypes. Epidemiologic studies suggest that weight loss via bariatric surgery results in metabolic reprogramming that reverses systemic aberrations as well as the protumorigenic effects of obesity; however, data on the effects of nonsurgical weight loss interventions in obese women remain inconclusive. We previously established that diet-induced obesity (DIO) increases tumor progression in murine models of basal-like BC. The purpose of this study was to determine if surgical and dietary weight loss interventions could effectively reduce obesity-associated tumor progression. Our first experiment directly compared mammary tumor growth following weight loss in DIO mice. Female C57BL/6 mice were randomized to a low-fat control (CON; 10 kcal% fat) diet or DIO regimen (60 kcal% fat) for 15 weeks. DIO mice were then randomized to either remain on DIO diet (DIO-DIO) or initiate weight loss either via vertical sleeve gastrectomy (DIO-SURG, with concurrent switch to control diet) or switch to control diet without surgery (DIO-DIET). CON mice remained on the 10 kcal% fat diet throughout the study. Eight weeks later, all mice were orthotopically injected with E0771 basal-like mammary tumor cells and were euthanized when tumors from the DIO-DIO group reached 1.5cm3. Body weights were not significantly different between DIO-SURG and DIO-DIET mice but both groups weighed significantly less than DIO-DIO mice. Compared with CON mice, tumor burden was not different in DIO-SURG mice but was significantly greater in DIO-DIET mice, suggesting that surgical weight loss more effectively reverses the protumorigenic effects of obesity than a low-fat diet. We next sought to determine how the anticancer effects of calorie restricted diets compared with bariatric surgery. Another group of female C57BL/6 received DIO diet for 16 weeks, then randomized to the same CON or DIO-SURG interventions as above, or to receive one of two calorie restriction (CR) diets—chronic CR (DIO-CCR; 30% daily calorie reduction) or intermittent CR (DIO-ICR; 14% calorie reduction 5 days per week, 70% calorie reduction on 2 nonconsecutive days per week). At time of tumor collection, DIO-SURG, DIO-CCR, and DIO-ICR mice weighed significantly less than DIO-DIO mice; however, only DIO-CCR and DIO-ICR mice achieved body weights significantly lower than CON mice. Tumor weights were significantly reduced in DIO-CCR and DIO-ICR fed mice, relative to CON mice, while tumor weights of DIO-SURG mice were intermediate. Moreover, multiple linear regression indicated weight loss, irrespective of intervention, was the strongest predictor of tumor mass. Our results in a murine model of basal-like BC suggest that weight loss via CR regimens (CCR, ICR) and, to a lesser extent, bariatric surgery, mitigates the pro-tumorigenic effects of obesity. Citation Format: Kristina K. Camp, Emily Rossi, Tori L. McFarlane, Steven Doerstling, Subreen Khatib, Elaine Glenny, Michael Coleman, Laura Bowers, Erika Rezeli, Randy J. Seeley, Alfor G. Lewis, Joel Parker, Anthony Fodor, Farnaz Fouladi, Stephen Hursting. Calorie restriction reverses the tumorigenic effects of obesity to a greater extent than bariatric surgery in a murine model of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2576.

Preoperative Nonsurgical Weight Loss Interventions Before Total Hip and Knee Arthroplasty: A Systematic Review

BackgroundAn upcoming total joint arthroplasty (TJA) may motivate patients with severe obesity (body mass index [BMI] > 40 kg/m2) to lose weight. Weight loss can optimize outcomes following TJA, and many surgeons use a 40 kg/m2 cut-off for undergoing TJA to reduce the risk of complications. However, few patients who are denied TJA for severe obesity successfully lose weight. This is the first systematic review of nonsurgical weight loss interventions before TJA. MethodsFive electronic databases were searched for articles on January 11, 2021. Studies that utilized preoperative nonsurgical weight loss interventions for patients with obesity (BMI ≥ 30 kg/m2) scheduled for or awaiting TJA of the hip or knee were included. Two reviewers independently screened articles, assessed methodological quality, and extracted data. ResultsWe retrieved 1943 unique records, of which 7 met inclusion criteria including 2 randomized clinical trials and 5 single-arm case series. Overall, weight loss ranged from 5.0 to 32.5 kg. Four interventions reduced BMI by 3 kg/m2 at 3-5 months, while 1 reduced BMI by 12.7 kg/m2. Other weight outcomes and those related to pain, function, complications, and adverse events were inconsistently reported. ConclusionAlthough larger trials are needed, particularly randomized controlled trials that measure preoperative weight loss in a control group, nutritional status, and postoperative complications, the available evidence indicates that short-term, nonsurgical, preoperative weight loss interventions before TJA produce both statistically significant weight loss and reduced BMI before surgery. It remains unknown if the amount of weight loss from these interventions is clinically significant and sufficient to improve outcomes after TJA.

The influence of bariatric surgery on hip and knee joint pain: a systematic review.

Obesity increases the risk of osteoarthritis and the chance of needing joint replacement arthroplasty to reduce lower limb joint pain. Although nonsurgical weight loss interventions can reduce hip and knee joint pain, bariatric surgery may be a more feasible treatment option for people with severe obesity. However, it is unclear whether weight loss through bariatric surgery can positively influence hip and knee joint pain. Our objective was to evaluate the influence of bariatric surgery on hip and knee joint pain in people with obesity by conducting a systematic review of the literature. The PubMed, EMBASE, and Cochrane bibliographic databases were searched for studies published between 1947 and September 2019. Risk of bias of the identified studies was independently assessed by 2 reviewers using JBI's Critical Appraisal Checklist for Case Series and the Newcastle-Ottawa Scale. This review included 23 studies, all of which evaluated knee pain and 9 of which also evaluated hip pain. Reported results regarding hip pain intensity and the proportion of participants with hip pain were too limited to draw useful conclusions. Reported results regarding knee pain suggest that weight loss after bariatric surgery reduced knee pain intensity, as well as the proportion of participants with knee pain. The overall risk of bias of the majority of included studies (83%; n = 19) was judged to be unclear to high. Four small studies were judged as having a low risk of bias. Results of this systematic review suggest that bariatric surgery can positively influence hip and knee joint pain, but conclusive evidence is lacking because most of the included studies were judged as having plausible bias overall and in their key domains. Well-designed randomized controlled trials evaluating the influence of bariatric surgery on hip and knee joint pain using standardized joint pain measures are needed.

Interventions for weight loss in people with chronic kidney disease who are overweight or obese.

Obesity and chronic kidney disease (CKD) are highly prevalent worldwide and result in substantial health care costs. Obesity is a predictor of incident CKD and progression to kidney failure. Whether weight loss interventions are safe and effective to impact on disease progression and clinical outcomes, such as death remains unclear. This review aimed to evaluate the safety and efficacy of intentional weight loss interventions in overweight and obese adults with CKD; including those with end-stage kidney disease (ESKD) being treated with dialysis, kidney transplantation, or supportive care. We searched the Cochrane Kidney and Transplant Register of Studies up to 14 December 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Randomised controlled trials (RCTs) and quasi-RCTs of more than four weeks duration, reporting on intentional weight loss interventions, in individuals with any stage of CKD, designed to promote weight loss as one of their primary stated goals, in any health care setting. Two authors independently assessed study eligibility and extracted data. We applied the Cochrane 'Risk of Bias' tool and used the GRADE process to assess the certainty of evidence. We estimated treatment effects using random-effects meta-analysis. Results were expressed as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) or standardised mean difference (SMD) for continuous outcomes or in descriptive format when meta-analysis was not possible. We included 17 RCTs enrolling 988 overweight or obese adults with CKD. The weight loss interventions and comparators across studies varied. We categorised comparisons into three groups: any weight loss intervention versus usual care or control; any weight loss intervention versus dietary intervention; and surgical intervention versus non-surgical intervention. Methodological quality was varied, with many studies providing insufficient information to accurately judge the risk of bias. Death (any cause), cardiovascular events, successful kidney transplantation, nutritional status, cost effectiveness and economic analysis were not measured in any of the included studies. Across all 17 studies many clinical parameters, patient-centred outcomes, and adverse events were not measured limiting comparisons for these outcomes. In studies comparing any weight loss intervention to usual care or control, weight loss interventions may lead to weight loss or reduction in body weight post intervention (6 studies, 180 participants: MD -3.69 kg, 95% CI -5.82 to -1.57; follow-up: 5 weeks to 12 months, very low-certainty evidence). In very low certainty evidence any weight loss intervention had uncertain effects on body mass index (BMI) (4 studies, 100 participants: MD -2.18 kg/m², 95% CI -4.90 to 0.54), waist circumference (2 studies, 53 participants: MD 0.68 cm, 95% CI -7.6 to 6.24), proteinuria (4 studies, 84 participants: 0.29 g/day, 95% CI -0.76 to 0.18), systolic (4 studies, 139 participants: -3.45 mmHg, 95% CI -9.99 to 3.09) and diastolic blood pressure (4 studies, 139 participants: -2.02 mmHg, 95% CI -3.79 to 0.24). Any weight loss intervention made little or no difference to total cholesterol, high density lipoprotein cholesterol, and inflammation, but may lower low density lipoprotein cholesterol. There was little or no difference between any weight loss interventions (lifestyle or pharmacological) compared to dietary-only weight loss interventions for weight loss, BMI, waist circumference, proteinuria, and systolic blood pressure, however diastolic blood pressure was probably reduced. Furthermore, studies comparing the efficacy of different types of dietary interventions failed to find a specific dietary intervention to be superior for weight loss or a reduction in BMI. Surgical interventions probably reduced body weight (1 study, 11 participants: MD -29.50 kg, 95% CI -36.4 to -23.35), BMI (2 studies, 17 participants: MD -10.43 kg/m², 95% CI -13.58 to -7.29), and waist circumference (MD -30.00 cm, 95% CI -39.93 to -20.07) when compared to non-surgical weight loss interventions after 12 months of follow-up. Proteinuria and blood pressure were not reported. All results across all comparators should be interpreted with caution due to the small number of studies, very low quality of evidence and heterogeneity across interventions and comparators. All types of weight loss interventions had uncertain effects on death and cardiovascular events among overweight and obese adults with CKD as no studies reported these outcome measures. Non-surgical weight loss interventions (predominately lifestyle) appear to be an effective treatment to reduce body weight, and LDL cholesterol. Surgical interventions probably reduce body weight, waist circumference, and fat mass. The current evidence is limited by the small number of included studies, as well as the significant heterogeneity and a high risk of bias in most studies.

Effects on body weight, eating behavior, and quality of life of a low-energy diet combined with behavioral group treatment of persons with class II or III obesity: A 2-year pilot study.

SummaryObjectiveObesity is associated with reduced health‐related quality of life (HRQoL). Outcomes of nonsurgical weight loss treatment on HRQoL are inconsistent and it is unclear how much weight reduction, or what type of treatment, is required for significant improvements. This study aimed to evaluate the effects of a lifestyle intervention program on weight, eating behaviors, and HRQoL, and to describe participants' experiences of treatment.MethodsThis 2‐year intervention trial in persons with class II or III obesity comprised a 3‐month liquid low‐energy diet (880 kcal/d) followed by a 3‐month reintroduction to regular foods, combined with behavioral group treatment.ResultsFifty‐five participants (73% women) were included, mean (SD) age 43.2 (12.4) years, and mean body mass index 42.0 (6.0) kg/m2. Mean weight loss at 6, 12, and 24 months was 18.9%, 13.7%, and 7.2%, respectively. Short‐ and long‐term effects on eating behavior were favorable. Twelve of 14 HRQoL domains were improved at 6 months, compared to eight domains at 12 months. After 24 months, 2 of 14 domains, physical and psychosocial functioning, were improved. The treatment program was well accepted by the participants.ConclusionsSubstantial weight loss after 6 months was associated with extensive improvements in HRQoL, comprising the physical, psychosocial, and mental domains. Significant weight regain was observed between 6 and 24 months follow‐up. Modest weight loss after 24 months was associated with moderate improvement in physical functioning and large improvement in psychosocial functioning. The effect on psychosocial functioning is most likely related to both weight loss and behavioral treatment.

Physiological and Epigenetic Features of Yoyo Dieting and Weight Control.

Obesity and being overweight have become a worldwide epidemic affecting more than 1.9 billion adults and 340 million children. Efforts to curb this global health burden by developing effective long-term non-surgical weight loss interventions continue to fail due to weight regain after weight loss. Weight cycling, often referred to as Yoyo dieting, is driven by physiological counter-regulatory mechanisms that aim at preserving energy, i.e. decreased energy expenditure, increased energy intake, and impaired brain-periphery communication. Models based on genetically determined set points explained some of the weight control mechanisms, but exact molecular underpinnings remained elusive. Today, gene–environment interactions begin to emerge as likely drivers for the obesogenic memory effect associated with weight cycling. Here, epigenetic mechanisms, including histone modifications and DNA methylation, appear as likely factors that underpin long-lasting deleterious adaptations or an imprinted obesogenic memory to prevent weight loss maintenance. The first part summarizes our current knowledge on the physiology of weight cycling by discussing human and murine studies on the Yoyo-dieting phenomenon and physiological adaptations associated with weight loss and weight re-gain. The second part provides an overview on known associations between obesity and epigenetic modifications. We further interrogate the roles of epigenetic mechanisms in the CNS control of cognitive functions as well as reward and addictive behaviors, and subsequently discuss whether such mechanisms play a role in weight control. The final two parts describe major opportunities and challenges associated with studying epigenetic mechanisms in the CNS with its highly heterogenous cell populations, and provide a summary of recent technological advances that will help to delineate whether an obese memory is based upon epigenetic mechanisms.

Impact of self-efficacy on risk aversion in the context of surgical weight loss decision scenarios.

Obesity is prevalent among a third of US adults and a leading indicator for many chronic diseases. Self-efficacy is important for non-surgical weight loss interventions, but there is less information about the role of self-efficacy in the candidacy phase when there are discussions of side effects and decisions for uptake. This study conducted an experiment set within an online survey assessing risk aversion towards bariatric surgery as a weight loss intervention. The survey asked about hypothetical weight loss scenarios for bariatric surgery among a national probability-based sample of US adults aged 18 years and older. Participants answered their willingness to achieve different weight loss amounts within the context of bariatric surgery in varying risk scenarios. The analysis utilized a repeated-measures linear mixed model. A three-way interaction demonstrated that participants were more willing to take risks under ideal weight loss conditions even with the risk of death, particularly when considering self-efficacy (𝛽 = 1.20, P = .05). Margin projections showed that those with lower self-efficacy were more likely to take risks overall. This trend was significant for those with a body mass index of 30 and above in scenarios presenting one's ideal weight as the outcome of bariatric surgery. Adding a measure of self-efficacy within patient assessments could identify those eligible patients who are most likely to adopt bariatric surgery, particularly among those who may have negative post-surgical outcomes due to low self-efficacy levels. Addressing self-efficacy by way of providing support resources in tandem with candidacy consultations may enhance quality of life and post-surgical outcomes.

Comparison of Endoscopic Bariatric Techniques

Endoscopic bariatric therapies have expanded our nonsurgical weight loss treatment options. Multiple current therapies exist, including endoscopic

Incremental cost-effectiveness of evidence-based non-surgical weight loss strategies.

Recent medical advancements have led to new modes of treatment for non-surgical weight loss, including several new medications. Our aim was to conduct an incremental cost-effectiveness analysis for all commercially available, evidence-based non-surgical weight loss interventions for people with excess weight. We identified interventions through a systematic review of randomized controlled trials that reported weight loss 12 months from baseline. We then meta-analysed the results, sourced costs and performed an incremental cost-effectiveness analysis from the payer perspective. Cost-effectiveness was presented in terms of cost per kilogram lost and quality-adjusted life years (QALY) gained. We further performed sensitivity analyses on costs and duration of benefits, and a probabilistic sensitivity analysis. Ten interventions were identified for inclusion: six pharmaceutical products (Alli, Xenical, Qsymia, Contrave, Belviq and Saxenda), two lifestyle modification programmes (Weight Watchers Meetings and Online), one food replacement and lifestyle programme (Jenny Craig) and one intragastric balloon system (Orbera). At an incremental cost-effectiveness ratio of $30 071 per additional QALY gained, only Weight Watchers Meetings was cost-effective. Sensitivity analyses revealed that for the medications to become incrementally cost-effective, costs would have to decrease by as much as 91%. Results are highly dependent on duration that benefits are maintained. Despite several newly available interventions, Weight Watchers Meetings is currently the only evidence-based, commercially available, cost-effective option for non-surgical weight loss. Other interventions, specifically medications, are more effective but priced too high to be cost-effective.

Eating self-efficacy as predictor of long-term weight loss and obesity-specific quality of life after sleeve gastrectomy: A prospective cohort study

BackgroundA person's confidence to control eating, eating self-efficacy (ESE), has been identified as a target for long-term weight management in nonsurgical weight loss interventions, but has to a limited extent been studied after bariatric surgery. ObjectiveWe investigated the association between ESE, weight loss, and obesity-specific quality of life (QOL) after sleeve gastrectomy (SG). SettingA single-center longitudinal study. MethodsData from adult patients were collected before SG, and at mean 16 months (±standard deviation 4 mo) and 55 (±4) months postoperatively. ESE was measured by the Weight Efficacy Lifestyle Questionnaire Short-Form. Multiple regression analyses were performed with excess body mass index loss (%EBMIL) and obesity-specific QOL as dependent variables. Age, sex, and other preoperative values were covariates in all models. ResultsOf 114 preoperative patients, 91 (80%) and 84 (74%) were available for follow-up 16 and 55 months after SG, respectively. Mean %EBMIL from baseline to 16 and 55 months was 76% (95% confidence interval: 71.9, 79.6) and 67% (95% confidence interval: 61.9, 72.2), respectively. Preoperative ESE scores improved significantly at both 16 and 55 months (P = .002) but did not predict postoperative %EBMIL or QOL at 55 months (β = −.08, P = .485). Greater change in ESE from 0 to 16 months predicted higher %EBMIL (β = .34, P = .013) at 55 months, and improvements in ESE from 0 to 55 months were significantly associated with higher %EBMIL (β = .46, P = .001) and obesity-specific QOL (β = .50, P < .001) 55 months after SG. ConclusionSignificant improvements in ESE were seen at 16 months, and remained high at 55 months after SG in this cohort. Patients who improved their ESE the most also experienced the highest weight loss and obesity-specific QOL 5 years postoperatively. Future research should address whether enhancement of ESE corresponds to sustained improvements in eating behavior after bariatric surgery.

Interventions for weight loss in people with chronic kidney disease who are overweight or obese

Background Obesity and chronic kidney disease (CKD) are highly prevalent worldwide and result in substantial health care costs. Obesity is a predictor of incident CKD and progression to kidney failure. Whether weight loss interventions are safe and effective to impact on disease progression and clinical outcomes, such as death remains unclear. Objectives This review aimed to evaluate the safety and efficacy of intentional weight loss interventions in overweight and obese adults with CKD; including those with end-stage kidney disease (ESKD) being treated with dialysis, kidney transplantation, or supportive care. Search methods We searched the Cochrane Kidney and Transplant Register of Studies up to 14 December 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Selection criteria Randomised controlled trials (RCTs) and quasi-RCTs of more than four weeks duration, reporting on intentional weight loss interventions, in individuals with any stage of CKD, designed to promote weight loss as one of their primary stated goals, in any health care setting. Data collection and analysis Two authors independently assessed study eligibility and extracted data. We applied the Cochrane 'Risk of Bias' tool and used the GRADE process to assess the certainty of evidence. We estimated treatment effects using random-effects meta-analysis. Results were expressed as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) or standardised mean difference (SMD) for continuous outcomes or in descriptive format when meta-analysis was not possible. Main results We included 17 RCTs enrolling 988 overweight or obese adults with CKD. The weight loss interventions and comparators across studies varied. We categorised comparisons into three groups: any weight loss intervention versus usual care or control; any weight loss intervention versus dietary intervention; and surgical intervention versus non-surgical intervention. Methodological quality was varied, with many studies providing insufficient information to accurately judge the risk of bias. Death (any cause), cardiovascular events, successful kidney transplantation, nutritional status, cost effectiveness and economic analysis were not measured in any of the included studies. Across all 17 studies many clinical parameters, patient-centred outcomes, and adverse events were not measured limiting comparisons for these outcomes. In studies comparing any weight loss intervention to usual care or control, weight loss interventions may lead to weight loss or reduction in body weight post intervention (6 studies, 180 participants: MD -3.69 kg, 95% CI -5.82 to -1.57; follow-up: 5 weeks to 12 months, very low-certainty evidence). In very low certainty evidence any weight loss intervention had uncertain effects on body mass index (BMI) (4 studies, 100 participants: MD -2.18 kg/m², 95% CI -4.90 to 0.54), waist circumference (2 studies, 53 participants: MD 0.68 cm, 95% CI -7.6 to 6.24), proteinuria (4 studies, 84 participants: 0.29 g/day, 95% CI -0.76 to 0.18), systolic (4 studies, 139 participants: -3.45 mmHg, 95% CI -9.99 to 3.09) and diastolic blood pressure (4 studies, 139 participants: -2.02 mmHg, 95% CI -3.79 to 0.24). Any weight loss intervention made little or no difference to total cholesterol, high density lipoprotein cholesterol, and inflammation, but may lower low density lipoprotein cholesterol. There was little or no difference between any weight loss interventions (lifestyle or pharmacological) compared to dietary-only weight loss interventions for weight loss, BMI, waist circumference, proteinuria, and systolic blood pressure, however diastolic blood pressure was probably reduced. Furthermore, studies comparing the efficacy of different types of dietary interventions failed to find a specific dietary intervention to be superior for weight loss or a reduction in BMI. Surgical interventions probably reduced body weight (1 study, 11 participants: MD -29.50 kg, 95% CI -36.4 to -23.35), BMI (2 studies, 17 participants: MD -10.43 kg/m², 95% CI -13.58 to -7.29), and waist circumference (MD -30.00 cm, 95% CI -39.93 to -20.07) when compared to non-surgical weight loss interventions after 12 months of follow-up. Proteinuria and blood pressure were not reported. All results across all comparators should be interpreted with caution due to the small number of studies, very low quality of evidence and heterogeneity across interventions and comparators. Authors' conclusions All types of weight loss interventions had uncertain effects on death and cardiovascular events among overweight and obese adults with CKD as no studies reported these outcome measures. Non-surgical weight loss interventions (predominately lifestyle) appear to be an effective treatment to reduce body weight, and LDL cholesterol. Surgical interventions probably reduce body weight, waist circumference, and fat mass. The current evidence is limited by the small number of included studies, as well as the significant heterogeneity and a high risk of bias in most studies.

How effective are weight-loss interventions for improving fertility in women and men who are overweight or obese? A systematic review and meta-analysis of the evidence.

The prevalence of obesity is increasing worldwide, with a corresponding increase in overweight and obese patients referred with infertility. This systematic review aimed to determine whether non-surgical weight reduction strategies result in an improvement in reproductive parameters affected by obesity, e.g. delayed time to pregnancy, oligozoospermia and azoospermia. No prior reviews have examined this within the general fertility population, or in both sexes. Our objective was to answer the question: 'In overweight and obese women, men and couples seeking fertility treatment, what non-surgical weight-loss interventions have been used, and how effective are they at weight loss and improving reproductive outcomes?' An electronic search of MEDLINE, EMBASE and the Cochrane Library was performed for studies between January 1966 and March 2016. Text word and MESH search terms used related to infertility, weight and barriers to weight loss. Inclusion criteria were an intervention to change lifestyle evaluated in any study design in participants of either gender with an unfulfilled desire to conceive. Studies were excluded if they included participants not attempting pregnancy, with illnesses that might cause weight fluctuations, or studies evaluating bariatric surgery. Two reviewers performed data extraction and quality assessment using the Cochrane Risk of Bias Tool for randomized trials, and a ratified checklist (ReBIP) for non-randomized studies. A total of 40 studies were included, of which 14 were randomised control trials. Primary outcomes were pregnancy, live birth rate and weight change. In women, reduced calorie diets and exercise interventions were more likely than control interventions to result in pregnancy [risk ratio 1.59, 95% CI (1.01, 2.50)], and interventions resulted in weight loss and ovulation improvement, where reported. Miscarriage rates were not reduced by any intervention. Overweight and obese persons seeking fertility should be educated on the detrimental effects of fatness and the benefits of weight reduction, including improvement in pregnancy rates. A combination of a reduced calorie diet, by reducing fat and refined carbohydrate intake, and increased aerobic exercise should form the basis of programmes designed for such individuals. A lack of randomized studies in men and couples, and studies evaluating barriers to undertaking weight loss in infertile populations is evident, and future research should examine these issues further.

Does intentional weight loss improve daytime sleepiness? A systematic review and meta-analysis.

Obesity is associated with excessive daytime sleepiness, but its causality remains unclear. We aimed to assess the extent to which intentional weight loss affects daytime sleepiness. Electronic databases were searched through 24 October 2016. Studies involving overweight or obese adults, a weight loss intervention and repeated valid measures of daytime sleepiness were included in the review. Two independent reviewers extracted data on study characteristics, main outcome (change in daytime sleepiness score standardized by standard deviation of baseline sleepiness scores), potential mediators (e.g. amount of weight loss and change in apnoea-hypopnoea index) and other co-factors (e.g. baseline demographics). Forty-two studies were included in the review. Fifteen before-and-after studies on surgical weight loss interventions showed large improvements in daytime sleepiness, with a standardized effect size of -0.97 (95% confidence interval [CI] -1.21 to -0.72). Twenty-seven studies on non-surgical weight loss interventions showed small-to-moderate improvement in daytime sleepiness, with a standardized effect size of -0.40 (95%CI -0.52 to -0.27), with no difference between controlled and before-and-after studies. We found a nonlinear association between amount of weight loss and change in daytime sleepiness. This review suggests that weight loss interventions improve daytime sleepiness, with a clear dose-response relationship. This supports the previously hypothesized causal effect of obesity on daytime sleepiness. It is important to assess and manage daytime sleepiness in obese patients.