Obesity medications: A narrative review of current and emerging agents

The aim of this narrative review is to synthesize the available data describing the efficacy and safety of medications approved for obesity management and to provide an overview of upcoming agents in development. A literature search of PubMed, Medline, and Embase databases identified relevant articles describing medications approved in the U.S., Australia, U.K., and/or Europe. Papers were selected based on relevance and originality, with phase 3 clinical trials and meta-analyses preferentially included. Six medications are widely approved for long-term weight management in conjunction with lifestyle interventions in people with body mass index (BMI) ≥30 ​kg/m2 or BMI ≥27 ​kg/m2 and at least one medical condition related to excess weight. Compared with lifestyle interventions alone, all medications approved for obesity management are more effective for long-term weight loss and improvements in cardiometabolic risk factors. Older obesity medications are associated with mean weight losses in the range of 5-10%. The new generation of agents, including the injectable incretin analogues semaglutide and tirzepatide are associated with sustained mean weight reductions of 15-20%, along with substantial benefits on a range of health outcomes. Several novel agents are under development, with multi-hormone receptor agonists and oral formulations likely to become available in the coming years. As effective treatment options expand, cost and availability will need to be addressed to enable equitable access to treatment. Other important challenges for clinical practice and research include the need for long-term strategies to prevent and manage weight regain and loss of lean muscle and bone mineral density.

Change in emotional eating after bariatric surgery: systematic review and meta-analysis

BACKGROUND

The effect of bariatric surgery on 'emotional eating' (EE) in people with obesity is unclear. This systematic review and meta-analysis aimed to examine changes in self-reported emotional eating behaviour after bariatric surgery.

METHODS

Fifteen electronic databases were searched from inception to August 2019. Included studies encompassed patients undergoing primary bariatric surgery, quantitatively assessed EE, and reported EE scores before and after surgery in the same participants. Studies were excluded if they were not in English or available in full text. The systematic review and meta-analysis were conducted according to the PRISMA guidelines. Random-effects models were used for quantitative analysis. Study quality was assessed using the National Heart, Lung, and Blood Institute quality assessment tool for before-after (pre-post) studies with no control group.

RESULTS

Some 23 studies containing 6749 participants were included in the qualitative synthesis, with follow-up of from 2 weeks to 48 months. EE scores decreased to 12 months after surgery. Results were mixed beyond 12 months. Quantitative synthesis of 17 studies (2811 participants) found that EE scores decreased by a standardized mean difference of 1·09 (95 per cent c.i. 0·76 to 1·42) 4-18 months after surgery, indicating a large effect size.

CONCLUSION

Bariatric surgery may mitigate the tendency to eat in response to emotions in the short to medium term.

Clinical Obesity Services in Public Hospitals in Australia: a position statement based on expert consensus

We aimed to describe the current state of specialist obesity services for adults with clinically severe obesity in public hospitals in Australia, and to analyse the gap in resources based on expert consensus. We conducted two surveys to collect information about current and required specialist obesity services and resources using open-ended questionnaires. Organizational level data were sought from clinician expert representatives of specialist obesity services across Australia in 2017. Fifteen of 16 representatives of current services in New South Wales (n = 8), Queensland (n = 1), Victoria (n = 2), South Australia (n = 3), and the Australian Capital Territory (n = 1) provided data. The composition of services varied substantially between hospitals, and patient access to services and effective treatments were limited by strict entry criteria (e.g. body mass index 40 kg/m² or higher with specific complication/s), prolonged wait times, geographical location (major cities only) and out-of-pocket costs. Of these services, 47% had a multidisciplinary team (MDT), 53% had an exercise physiologist/physiotherapist, 53% had a bariatric surgeon and 33% had pharmacotherapy resources. Key gaps included staffing components of the MDT (psychologist, exercise physiologist/physiotherapist) and access to publicly funded weight loss pharmacotherapy and bariatric surgery. There was consensus on the need for significant improvements in staff, physical infrastructure, access to services, education/training in obesity medicine and targeted research funding. Based on the small number of existing, often under-resourced specialist obesity services that are located only in a few major cities, the vast majority of Australians with clinically severe obesity cannot access the specialist evidence based treatments needed.

Combining biological and psychosocial baseline variables did not improve prediction of outcome of a very-low-energy diet in a clinic referral population

Consistent, strong predictors of obesity treatment outcomes have not been identified. It has been suggested that broadening the range of predictor variables examined may be valuable. We explored methods to predict outcomes of a very-low-energy diet (VLED)-based programme in a clinically comparable setting, using a wide array of pre-intervention biological and psychosocial participant data. A total of 61 women and 39 men (mean ± standard deviation [SD] body mass index: 39.8 ± 7.3 kg/m² ) underwent an 8-week VLED and 12-month follow-up. At baseline, participants underwent a blood test and assessment of psychological, social and behavioural factors previously associated with treatment outcomes. Logistic regression, linear discriminant analysis, decision trees and random forests were used to model outcomes from baseline variables. Of the 100 participants, 88 completed the VLED and 42 attended the Week 60 visit. Overall prediction rates for weight loss of ≥10% at weeks 8 and 60, and attrition at Week 60, using combined data were between 77.8 and 87.6% for logistic regression, and lower for other methods. When logistic regression analyses included only baseline demographic and anthropometric variables, prediction rates were 76.2-86.1%. In this population, considering a wide range of biological and psychosocial data did not improve outcome prediction compared to simply-obtained baseline characteristics.

Review of 3-year outcomes of a very-low-energy diet-based outpatient obesity treatment programme

Obesity is a complex disorder that requires a multidisciplinary treatment approach. This review evaluated 3-year outcomes of a very-low-energy diet (VLED)-based programme at a tertiary hospital multidisciplinary weight management clinic. Medical records of all patients who agreed to undertake the VLED programme and who did not undergo bariatric surgery during the 3-year follow-up period were examined. Baseline data collection included demographic and anthropometric characteristics, childhood onset of obesity and co-existing medical conditions. Weight was modelled using a linear mixed effects analysis. Logistic regression analyses were used to model the probability of continuing to attend the clinic and to identify pre-treatment factors associated with longer duration of attendance. Data from 1109 patients were included. A total of 231 patients (19.2%) were still attending the clinic 3 years after their initial appointment. Mean weight loss among patients who attended the clinic for 3 years was 6.4 kg (3.5%, 95% confidence interval [CI] 2.8, 4.2%). People who were prescribed pharmacotherapy maintained greater weight loss at 3 years (7.7% vs. 2.3% without pharmacotherapy, 95% CI for difference 3.9, 7.0%). People who had an onset of obesity in childhood, who had co-existing hypertension or coronary artery disease, and who did not currently smoke were more likely to continue to attend the clinic for up to 3 years. In summary, in an outpatient weight management clinic, patients who undertook a VLED-based programme and continued in follow-up achieved a clinically significant weight loss at 3 years, particularly if pharmacotherapy was used for weight loss maintenance.

Ketosis and appetite-mediating nutrients and hormones after weight loss

BACKGROUND/OBJECTIVES

Diet-induced weight loss is accompanied by compensatory changes, which increase appetite and encourage weight regain. There is some evidence that ketogenic diets suppress appetite. The objective is to examine the effect of ketosis on a number of circulating factors involved in appetite regulation, following diet-induced weight loss.

SUBJECTS/METHODS

Of 50 non-diabetic overweight or obese subjects who began the study, 39 completed an 8-week ketogenic very-low-energy diet (VLED), followed by 2 weeks of reintroduction of foods. Following weight loss, circulating concentrations of glucose, insulin, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), leptin, gastrointestinal hormones and subjective ratings of appetite were compared when subjects were ketotic, and after refeeding.

RESULTS

During the ketogenic VLED, subjects lost 13% of initial weight and fasting BHB increased from (mean±s.e.m.) 0.07±0.00 to 0.48±0.07 mmol/l (P<0.001). BHB fell to 0.19±0.03 mmol/l after 2 weeks of refeeding (P<0.001 compared with week 8). When participants were ketotic, the weight loss induced increase in ghrelin was suppressed. Glucose and NEFA were higher, and amylin, leptin and subjective ratings of appetite were lower at week 8 than after refeeding.

CONCLUSIONS

The circulating concentrations of several hormones and nutrients which influence appetite were altered after weight loss induced by a ketogenic diet, compared with after refeeding. The increase in circulating ghrelin and subjective appetite which accompany dietary weight reduction were mitigated when weight-reduced participants were ketotic.