The impact of continued intervention on weight: Five-year results from the weight loss maintenance trial

Weight Regain After Bariatric Surgery: Scope of the Problem, Causes, Prevention, and Treatment

PURPOSE OF REVIEW

Although bariatric surgery is the most effective treatment of severe obesity, a proportion of patients experience clinically significant weight regain (WR) with further out from surgery. The purpose of this review is to summarize the prevalence, predictors, and causes of weight regain.

RECENT FINDINGS

Estimating the prevalence of WR is limited by a lack of consensus on its definition. While anatomic failures such as dilated gastric fundus after sleeve gastrectomy and gastro-gastric fistula after Roux-en-Y gastric bypass can lead to WR, the most common causes appear to be dysregulated/maladaptive eating behaviors, lifestyle factors, and physiological compensatory mechanisms. To date, dietary, supportive, behavioral, and exercise interventions have not demonstrated a clinically meaningful impact on WR, and there is limited evidence for pharmacotherapy. Future studies should be aimed at better defining WR to begin to understand the etiologies. Additionally, there is a need for non-surgical interventions with demonstrated efficacy in rigorous randomized controlled trials for the prevention and reversal of WR after bariatric surgery.

Effect of unsaturated fat and protein intake on liver fat in people at risk of unhealthy aging: 1-year results of a randomized controlled trial

BACKGROUND

Short-term trials indicate improvement of intrahepatic lipids (IHLs) and metabolism by dietary protein or unsaturated fatty acids (UFAs) beyond weight loss.

OBJECTIVES

We aimed to assess the effect of a dietary intervention high in protein and UFAs on IHLs and metabolic outcome after 12 mo, as long-term effects of such a combined intervention are unknown.

METHODS

Within a 36-mo randomized controlled trial, eligible subjects (aged 50 to 80 y, ≥1 risk factor for unhealthy aging) were randomly assigned to either intervention group (IG) with high intake of mono-/poly-UFAs [15-20 percent of total energy (%E)/10%-15%E, respectively], plant protein (15%-25%E), and fiber (≥30 g/d), or control group [CG, usual care, dietary recommendations of the German Nutrition Society (fat 30%E/carbohydrates 55%E/protein 15%E)]. Stratification criteria were sex, known cardiovascular disease, heart failure, arterial hypertension, type 2 diabetes, and cognitive or physical impairment. Nutritional counseling and supplementation of foods mirroring the intended dietary pattern were performed in the IG. Diet-induced effects on IHLs, analyzed by magnetic resonance spectroscopy, as well as on lipid and glucose metabolism were predefined secondary endpoints.

RESULTS

IHL content was analyzed in 346 subjects without significant alcohol consumption at baseline and in 258 subjects after 12 mo. Adjusted for weight loss, sex, and age, we observed a comparable decline of IHLs in IG and CG (-33.3%; 95% CI: -49.3, -12.3%; n = 128 compared with -21.8%; 95% CI: -39.7, 1.5%; n = 130; P = 0.179), an effect that became significant by comparing adherent IG subjects to adherent CG subjects (-42.1%; 95% CI: -58.1, -20.1%; n = 88 compared with -22.2%; 95% CI: -40.7, 2.0%; n = 121; P = 0.013). Compared with the CG, decline of LDL cholesterol (LDL-C) and total cholesterol (TC) was stronger in the IG (for LDL-C P = 0.019, for TC P = 0.010). Both groups decreased in triglycerides and insulin resistance (P for difference between groups P = 0.799 and P = 0.124, respectively).

CONCLUSIONS

Diets enriched with protein and UFAs have beneficial long-term effects on liver fat and lipid metabolism in adherent older subjects. This study was registered at the German Clinical Trials Register, https://www.drks.de/drks_web/setLocale_EN.do, DRKS00010049. Am J Clin Nutr 20XX;xx:xx-xx.

Weight loss-induced improvement of body weight and insulin sensitivity is not amplified by a subsequent 12-month weight maintenance intervention but is predicted by adaption of adipose atrial natriuretic peptide system: 48-month results of a randomized controlled trial

BACKGROUND

Behavioral weight loss interventions are frequently hampered by long-term inefficacy. As metabolic improvements and health-related quality of life (HRQoL) are diminished by weight regain, effective long-term strategies are highly desirable. We aimed to analyze whether an additional weight maintenance intervention could delay body weight regain and can induce a long-term improvement of metabolism and HRQoL for up to 48 months in humans. Given the short-term metabolic effects of natriuretic peptides (NP), we also investigated the role of the adipose atrial NP (ANP) system in this long-term context.

METHODS

After a successful 12-week weight reduction program 143 subjects (age>18; BMI≥27 kg/m²) were randomized (1:1) to a control group or a 12-month multimodal weight maintenance intervention focusing on nutritional counseling and physical exercises. Secondary trial outcomes including course of BMI, HOMA-IR, glucose response after oGTT (glucose_AUC), and HRQoL (SF-36) were analyzed yearly for 48 months. Adipose ANP receptor mRNA expression was analyzed during weight loss.

RESULTS

Initial weight loss (- 4.7±1.5 kg/m²) improved glucose_AUC, HOMA-IR, and HRQoL. Although BMI was still reduced after 48 months (-1.98 [95% CI -2.61, -1.35] kg/m²), benefits on HOMA-IR, glucose_AUC, and mental health disappeared after 36 (-0.49 [-1.00, 0.02]), 18 (0.61 [-9.57, 10.79] mg dl^-1 min^-1), and 18 months (2.06 [-0.08, 4.20]), respectively, while improved physical health persisted up to months 48 (2.95 [0.49, 5.40]). Weight maintenance intervention inhibited weight regain and delayed impairment of HOMA-IR and glucose_AUC (but not HRQoL) for up to 12 months. However, no metabolic long-term effect was seen beyond the intervention period. Lower adipose NPR-C and higher NPR-A mRNA expression after weight loss predicted smaller regain of weight (r=0.398; p<0.05)/fat mass (FM) (r=0.391; p<0.05) and longer improvement of HOMA-IR (r=-0.422; p<0.05), respectively.

CONCLUSIONS

Additional benefits of a behavioral 12-month weight maintenance intervention after weight loss regarding body weight regain and metabolic improvement does not persist beyond the intervention period. However, weight loss-induced modulation of the adipose ANP system is probably involved in the long-term control of body weight regain and insulin sensitivity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00850629 . Registered on February 25, 2009.

Outcomes of bariatric surgery in elderly patients: a registry-based cohort study with 3-year follow-up

BACKGROUND

Elderly patients undergo bariatric surgery less frequently than younger patients. Short- and medium-term outcomes after bariatric surgery in the elderly population remain largely unknown. The objective of the present retrospective, registry-based cohort study was to compare short- and medium-term outcomes between patients <65 and ≥65 years undergoing bariatric surgery, hypothesizing similar outcomes between groups.

METHODS

In this retrospective, registry-based cohort study, the Ontario Bariatric Registry was used to compare data of patients <65 and ≥65 years who underwent Roux-en-Y gastric bypass and sleeve gastrectomy between January 2010 and August 2019 in all accredited bariatric centers of excellence in Ontario, Canada. Primary outcomes were overall postoperative complications. Secondary outcomes included early (<30 days) complications, readmissions, reoperations, mortality, weight loss and comorbidities improvement at 1 and 3 year after surgery.

RESULTS

Data of 22,981 patients <65 and 532 patients ≥65 years were analyzed. Overall postoperative complications were similar between patients <65 and ≥65 years (3388/22,981 [14.7%] vs. 73/532 [13.7%], p = 0.537). Early (<30 days) postoperative complications, readmissions, reoperations, and mortality rates were also similar between groups. Both groups had significant weight loss and comorbidities improvement at 1- and 3-year follow-up. Patients <65 years had superior weight loss (+3.5%, 95% CI: 1.6-5.4, p < 0.001) and higher rates of remission for diabetes mellitus (63.8% vs. 39.3%, p < 0.001), hypertension (37.9% vs. 14.5%, p < 0.001), dyslipidemia (28.2% vs. 9.5%, p < 0.001) and gastroesophageal reflux (65.1% vs. 24.0 %, p < 0.001) compared to patients ≥65 years at 3 year.

CONCLUSIONS

Patients <65 and ≥65 years had similar perioperative morbidity and mortality after bariatric surgery. Even though patients <65 years had overall better medium-term outcomes, bariatric surgery is safe and yields significant weight loss and comorbidities improvement in patients ≥65 years.

Fetuin-B, a potential link of liver-adipose tissue cross talk during diet-induced weight loss-weight maintenance

Background/objectives

Numerous hepatokines are involved in inter-organ cross talk regulating tissue-specific insulin sensitivity. Adipose tissue lipolysis represents a crucial element of adipose insulin sensitivity and is substantially involved in long-term body weight regulation after dietary weight loss. Thus, we aimed to analyze the impact of the hepatokine Fetuin-B in the context of weight loss induced short- and long-term modulation of adipose insulin sensitivity.

Subjects/methods

143 subjects (age > 18; BMI ≥ 27 kg/m²) were analyzed before (T-3) and after (T0) a standardized 12-week dietary weight reduction program. Afterward, subjects were randomized to a 12-month lifestyle intervention or a control group. After 12 months (T12) no further intervention was performed until 6 months later (T18) (Maintain-Adults trial). Tissue-specific insulin sensitivity was estimated by HOMA-IR (predominantly liver), ISI_Clamp (predominantly skeletal muscle), and free fatty acid suppression during hyperinsulinemic-euglycemic clamp (FFA_Supp) (predominantly adipose tissue). Fetuin-B was measured at all concomitant time points.

Results

Circulating Fetuin-B levels correlated significantly with estimates of obesity, hepatic steatosis as well as HOMA-IR, ISI_Clamp, FFA_Supp at baseline. Fetuin-B decreased during dietary weight loss (4.2 (3.5–4.9) vs. 3.8 (3.2–4.6) µg/ml; p = 2.1 × 10⁻⁵). This change was associated with concomitant improvement of HOMA-IR (r = 0.222; p = 0.008) and FFA_Supp (r = −0.210; p = 0.013), suggesting a particular relationship to hepatic and adipose tissue insulin sensitivity. Weight loss induced improvements of insulin resistance were almost completely preserved until months 12 and 18 and most interestingly, the short and long-term improvement of FFA_Supp was partially predicted by baseline level of Fetuin-B.

Conclusions

Our data suggest that Fetuin-B might be a potential mediator of liver-adipose cross talk involved in short- and long-term regulation of adipose insulin sensitivity, especially in the context of diet-induced weight changes.

Trial registration

ClinicalTrials.gov number: NCT00850629, https://clinicaltrials.gov/ct2/show/NCT00850629, date of registration: February 25, 2009.

Two-year weight trajectories following completion of a behavioral weight loss maintenance intervention

Introduction

Long‐term effects of behavioral weight loss maintenance interventions need to be assessed in order to understand their durability of effects. This can be evaluated with the use of weights recorded in the electronic medical record. The goal of this study was to use electronic health record (EHR)‐recorded weight to examine outcomes 2 years beyond the completion of a trial in which participants were randomized to receive a weight maintenance intervention or usual care after required initial weight loss.

Methods

Weights collected in the Veteran's Affairs national EHR were obtained for 2 years following trial completion. Outliers and implausible weights were identified and removed prior to analysis. Mixed‐effects models with quadratic time were fit to estimate between‐arm differences in weight change.

Results

Model‐estimated weight at trial completion was 109.7 kg for usual care and 106.8 kg for intervention, estimated difference of −2.9 kg (95% confidence interval [CI]: −8.8, 3.0; p = 0.34). Two years later, estimated mean weight collected from (n = 211) participants with available EMR weights was 111.5 kg for usual care and 108.0 kg for intervention, estimated difference −3.4 kg (95% CI: −9.3, 2.4 kg; p = 0.35).

Conclusions

While not statistically significant, weights from the EHR suggest the possibility of a clinically meaningful difference that should be confirmed by future adequately powered studies.

Behavioral Counseling to Promote a Healthy Diet and Physical Activity for Cardiovascular Disease Prevention in Adults With Cardiovascular Risk Factors: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease is the leading cause of death in the US, and poor diet and lack of physical activity are major factors contributing to cardiovascular morbidity and mortality.

OBJECTIVE

To review the benefits and harms of behavioral counseling interventions to improve diet and physical activity in adults with cardiovascular risk factors.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, and the Cochrane Central Register of Controlled Trials through September 2019; literature surveillance through July 24, 2020.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of behavioral counseling interventions to help people with elevated blood pressure or lipid levels improve their diet and increase physical activity.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from studies by one reviewer and checked by a second. Random-effects meta-analysis and qualitative synthesis were used.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, mortality, subjective well-being, cardiovascular risk factors, diet and physical activity measures (eg, minutes of physical activity, meeting physical activity recommendations), and harms. Interventions were categorized according to estimated contact time as low (≤30 minutes), medium (31-360 minutes), and high (>360 minutes).

RESULTS

Ninety-four RCTs were included (N = 52 174). Behavioral counseling interventions involved a median of 6 contact hours and 12 sessions over the course of 12 months and varied in format and dietary recommendations; only 5% addressed physical activity alone. Interventions were associated with a lower risk of cardiovascular events (pooled relative risk, 0.80 [95% CI, 0.73-0.87]; 9 RCTs [n = 12 551]; I2 = 0%). Event rates were variable; in the largest trial (Prevención con Dieta Mediterránea [PREDIMED]), 3.6% in the intervention groups experienced a cardiovascular event, compared with 4.4% in the control group. Behavioral counseling interventions were associated with small, statistically significant reductions in continuous measures of blood pressure, low-density lipoprotein cholesterol levels, fasting glucose levels, and adiposity at 12 to 24 months' follow-up. Measurement of diet and physical activity was heterogeneous, and evidence suggested small improvements in diet consistent with the intervention recommendation targets but mixed findings and a more limited evidence base for physical activity. Adverse events were rare, with generally no group differences in serious adverse events, any adverse events, hospitalizations, musculoskeletal injuries, or withdrawals due to adverse events.

CONCLUSIONS AND RELEVANCE

Medium- and high-contact multisession behavioral counseling interventions to improve diet and increase physical activity for people with elevated blood pressure and lipid levels were effective in reducing cardiovascular events, blood pressure, low-density lipoproteins, and adiposity-related outcomes, with little to no risk of serious harm.

Text messaging and financial incentives to encourage weight loss in men with obesity: the Game of Stones feasibility RCT

Background

In 2016, 26% of UK men were estimated to be obese. Systematic reviews suggest that few men engage in formal weight loss interventions that support weight reduction and improve health.

Objective

To co-produce, with patient and public involvement, an acceptable and feasible randomised controlled trial design to test a men-only weight management intervention.

Design

This was a two-phase feasibility study. Phase 1 was the development of intervention components, study procedures and materials including a discrete choice experiment with survey questions. Phase 2 was an individually randomised three-arm feasibility trial over 12 months. Qualitative interviews were conducted at 3 and 12 months.

Setting

The setting was two sites in Scotland that had disadvantaged urban and rural areas and differed in employment levels and ethnic groups.

Participants

In phase 1, 1045 men with obesity were recruited by Ipsos MORI (London, UK; www.ipsos.com/ipsos-mori/en-uk) to represent the UK population. In phase 2, 105 men with obesity were recruited in the community or through general practice obesity registers. Qualitative interviews were conducted with 50 men at 3 months and with 33 men at 12 months.

Interventions

The trial arms were narrative short message service (SMS) for 12 months (SMS only), financial endowment incentive informed by loss aversion and linked to achievement of weight loss targets plus narrative SMS for 12 months (SMS + I), and waiting list control group for 12 months followed by 3 months of an alternative SMS style developed based on feedback from men who had received the narrative SMS (control).

Main outcome measures

The main outcome measures were acceptability and feasibility of recruitment, retention, engagement, intervention components and trial procedures. Outcomes were assessed by examining procedural, quantitative and qualitative data at 3, 6 and 12 months.

Results

The most acceptable incentive strategy, based on the discrete choice experiment results, was to verify weight loss of 5% at 3 months, verify weight loss of 10% at 6 months and maintain weight loss of 10% at 12 months. Overall, 105 men with obesity from across the socioeconomic spectrum were successfully recruited to target, 59% of whom lived in more disadvantaged areas. Retention at 12 months was acceptable (74%) and was higher among individuals from disadvantaged areas. Narrative SMS were acceptable to many men, with a minority reporting negative reactions. Incentives were acceptable but were not the primary motivation for behaviour change. Twelve men in the incentive arm (33%) secured at least some money and three (8%) secured the full amount. Both intervention arms lost some weight, with greater weight loss in the arm that received SMS and incentives. The alternative SMS based on men’s feedback received no strong negative reactions.

Limitations

Fewer participants from the SMS + I arm (64%) completed the study at 12 months than did those in the SMS-only (79%) and control (83%) arms. The reasons for this difference were complex.

Conclusions

The men-only weight management intervention consisting of narrative SMS and financial incentives was acceptable and feasible, meeting the progression criteria for a full trial. Tailoring of SMS may improve acceptability and retention.

Future work

Minor refinements to the intervention components based on the study findings will be made prior to testing in a multisite definitive randomised controlled trial.

Trial registration

ClinicalTrials.gov NCT03040518.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 11. See the NIHR Journals Library website for further project information.

The limits and challenges of antiobesity pharmacotherapy

INTRODUCTION

Pharmacotherapy is a useful adjunct when patients with obesity are unable to achieve adequate benefit from lifestyle interventions.

AREAS COVERED

This review covers the history of antiobesity drugs, efficacy, and risks of currently approved drugs, limits of their usefulness in clinical practice, gaps in knowledge, methodological limitations of clinical trials, and reasons for underutilization.

EXPERT OPINION

In randomized controlled trials, currently approved antiobesity drugs have yielded an average weight loss ranging from approximately 3% to 9% relative to placebo at 1 year. Inadequate inclusion of racial and ethnic minorities and men, and high dropout rates in clinical trials limit generalizability of these findings to clinical practice. Weight loss achieved with antiobesity drugs is generally associated with lowered glycemia, but improvements in blood pressure and lipid measures tend to be marginal. There is limited evidence for sustained weight loss beyond 1 year and for safety and efficacy of antiobesity drugs in children and adolescents, and in post-bariatric surgery patients. None have demonstrated reduction in major adverse cardiovascular events or other significant disease outcomes. Limited health insurance coverage and negative perceptions of physicians have hindered the utilization of antiobesity drugs.

The Effect of Bariatric Surgery on Weight Loss and Metabolic Changes in Adults with Obesity

Methods of treating obesity, such as changes in lifestyle, physical activity, restrictive diets, and psychotherapy, are not sufficient. Currently, it is considered that in the case of patients who meet the eligibility criteria for surgery, the treatment of choice should be bariatric surgery. The aim of this study was to assess the weight loss and metabolic changes in a group of adults with obesity undergoing bariatric surgery. The study involved 163 patients whose body mass index (BMI) exceeded 40 or 35 kg/m², concurrent with at least one metabolic sequelae. In 120 of the cases (74%), sleeve gastrectomy was used; in 35 (21%), gastric banding was used; and in 8 (5%), laparoscopic Roux-en-Y gastric bypass was used. Metabolic parameters such as total cholesterol, LDL-cholesterol (low-density lipoprotein cholesterol), HDL-cholesterol (high-density lipoprotein cholesterol), triglycerides, and glucose were measured preoperatively and postoperatively, as well as the creatinine, creatine kinase (CK-MB), and leptin activity. In patients undergoing bariatric surgery, a significant decrease in excess weight (p < 0.001) was observed at all the analyzed time points, compared to the pre-surgery value. Weight loss after surgery was associated with a significant improvement in glycemia (109.6 ± 48.0 vs. 86.6 ± 7.9 mg/dL >24 months after surgery; p = 0.003), triglycerides (156.9 ± 79.6 vs. 112.7 ± 44.3 mg/dL >24 months after surgery; p = 0.043) and leptin (197.50 ± 257.3 vs. 75.98 ± 117.7 pg/mL 12 months after surgery; p = 0.0116) concentration. The results of the research confirm the thesis on the effectiveness of bariatric surgery in reducing excess body weight and improving metabolic parameters in patients with extreme obesity.

Weight Change 2 Years After Termination of the Intensive Lifestyle Intervention in the Look AHEAD Study

OBJECTIVE

This study evaluated weight changes after cessation of the 10-year intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study. It was hypothesized that ILI participants would be more likely to gain weight during the 2-year observational period following termination of weight-loss-maintenance counseling than would participants in the diabetes support and education (DSE) control group.

METHODS

Look AHEAD was a randomized controlled trial that compared the effects of ILI and DSE on cardiovascular morbidity and mortality in participants with overweight/obesity and type 2 diabetes. Look AHEAD was converted to an observational study in September 2012.

RESULTS

Two years after the end of the intervention (EOI), ILI and DSE participants lost a mean  (SE) of 1.2  (0.2) kg and 1.8  (0.2) kg, respectively (P = 0.003). In addition, 31% of ILI and 23.9% of DSE participants gained ≥ 2% (P < 0.001) of EOI weight, whereas 36.3% and 45.9% of the respective groups lost ≥ 2% of EOI weight (P = 0.001). Two years after the EOI, ILI participants reported greater use of weight-control behaviors than DSE participants.

CONCLUSIONS

Both groups lost weight during the 2-year follow-up period, but more ILI than DSE participants gained ≥ 2% of EOI weight. Further understanding is needed of factors that affected long-term weight change in both groups.

Four main barriers to weight loss maintenance? A quantitative analysis of difficulties experienced by obese patients after successful weight reduction

BACKGROUND

Weight maintenance remains to be a challenge for patients in a reduced obese state and it has been recommended to provide them more individualized support. For this purpose it is crucial to understand the barriers patients are experiencing after weight loss. Many have been identified by qualitative studies. We evaluated if a quantitative assessment of patient perspective during weight maintenance can help identify major barriers that refer to actual regain.

METHODS

Follow-up data were analyzed from patients attempting weight maintenances after successful completion of a nonsurgical weight loss and lifestyle intervention for morbid obesity. The data were acquired at mandatory follow-up assessments and included rating of 26 probable difficulties. A principal component analysis was carried out to explore whether these difficulties could be grouped into meaningful factors. Associations with socio-demographics, follow-up time, and weight changes were evaluated.

RESULTS

Data from 88 out of 102 patients were available (baseline BMI 49.5 ± 7.4 kg/m²; 12-month weight loss 24.3 ± 9.6%; follow-up time 1.48 ± 0.6 years). Four solid factors, composed of 21 items and explaining 56% of the variance were extracted and interpreted as 'Hedonic Hunger', 'Mental Distress', 'Binge Eating', and 'Demoralization'. Weight regain (12.4 ± 12%) was correlated with each factor, most closely with 'Mental Distress' (r = 0.38). When controlling for age and follow-up time, 'Binge Eating' was the most important predictor (adj. R² = 0.297).

CONCLUSIONS

A quantitative assessment of patient perspective during the first years after weight loss can help identify valid barriers to weight loss maintenance.

Long-term Weight Loss Maintenance in the Continuation of a Randomized Diabetes Prevention Translational Study: The Healthy Living Partnerships to Prevent Diabetes (HELP PD) Continuation Trial

OBJECTIVE

HELP PD was a clinical trial of 301 adults with prediabetes. Participants were randomized to enhanced usual care (EUC) or to a lifestyle weight loss (LWL) intervention led by community health workers that consisted of a 6-month intensive phase (phase 1) and 18 months of maintenance (phase 2). At 24 months, participants were asked to enroll in phase 3 to assess whether continued group maintenance (GM) sessions would maintain improvements realized in phases 1 and 2 compared with self-directed maintenance (SM) or EUC.

RESEARCH DESIGN AND METHODS

In phase 3, LWL participants were randomly assigned to GM or SM. EUC participants remained in the EUC arm and, along with participants in SM, received monthly newsletters. All participants received semiannual dietitian sessions. Anthropometrics and biomarkers were assessed every 6 months. Mixed-effects models were used to assess changes in outcomes over time.

RESULTS

Eighty-two of the 151 intervention participants (54%) agreed to participate in phase 3; 41 were randomized to GM and 41 to SM. Of the 150 EUC participants, 107 (71%) continued. Ninety percent of clinic visits were completed. Over 48 months of additional follow-up, outcomes remained relatively stable in the EUC participants; the GM group was able to maintain body weight, BMI, and waist circumference; and these measures all increased significantly (P < 0.001) in the SM group.

CONCLUSIONS

Participants in the GM arm maintained weight loss achieved in phases 1 and 2, while those in the SM arm regained weight. Because group session attendance by the participants in the GM arm was low, it is unclear what intervention components led to successful weight maintenance.

Dietary Strategies for Weight Loss Maintenance

Weight regain after a successful weight loss intervention is very common. Most studies show that, on average, the weight loss attained during a weight loss intervention period is not or is not fully maintained during follow-up. We review what is currently known about dietary strategies for weight loss maintenance, focusing on nutrient composition by means of a systematic review and meta-analysis of studies and discuss other potential strategies that have not been studied so far. Twenty-one studies with 2875 participants who were overweight or obese are included in this systematic review and meta-analysis. Studies investigate increased protein intake (12 studies), lower dietary glycemic index (four studies), green tea (three studies), conjugated linoleic acid (three studies), higher fibre intake (three studies), and other miscellaneous interventions (six studies). The meta-analysis shows a significant beneficial effect of higher protein intake on the prevention of weight regain (SMD (standardized mean difference) -0.17 (95% CI -0.29, -0.05), z = 2.80, p = 0.005), without evidence for heterogeneity among the included studies. No significant effect of the other strategies is detected. Diets that combine higher protein intake with different other potentially beneficial strategies, such as anti-inflammatory or anti-insulinemic diets, may have more robust effects, but these have not been tested in randomized clinical trials yet.

An Integrated Understanding of the Molecular Mechanisms of How Adipose Tissue Metabolism Affects Long-term Body Weight Maintenance

Lifestyle-based weight loss interventions frequently demonstrate long-term inefficiency and weight regain. Identification of underlying mechanisms and predictors to identify subjects who will benefit from lifestyle-based weight loss strategies is urgently required. We analyzed 143 adults of the randomized Maintain trial (Maintain-Adults) after intended weight loss to identify mechanisms contributing to the regulation of body weight maintenance. Unbiased RNA sequencing of adipose and skeletal muscle biopsies revealed fatty acid metabolism as a key pathway modified by weight loss. Variability of key enzymes of this pathway, estimates of substrate oxidation, and specific serum acylcarnitine (AC) species, representing a systemic snapshot of in vivo substrate flux, predicted body weight maintenance (defined as continuous or dichotomized [< or ≥3% weight regain] variable) 18 months after intended weight loss in the entire cohort. Key results were confirmed in a similar randomized controlled trial in 137 children and adolescents (Maintain-Children), which investigated the same paradigm in a pediatric cohort. These data suggest that adaption of lipid utilization in response to negative energy balance contributes to subsequent weight maintenance. Particularly a functional role for circulating ACs, which have been suggested to reflect intracellular substrate utilization, as mediators between peripheral energy stores and control of long-term energy homeostasis was indicated.

Obesity and Weight Loss in Idiopathic Intracranial Hypertension: A Narrative Review

BACKGROUND

Most patients with idiopathic intracranial hypertension (IIH) are obese. Weight loss is felt to be an important factor in improving IIH. The mechanism by which weight loss leads to a reduction in elevated intracranial pressure is unclear. Evidence from prospective studies evaluating the role of weight loss in IIH is lacking.

EVIDENCE ACQUISITION

We performed a detailed review of the published literature regarding the association of IIH and obesity, including proposed pathogenetic mechanisms, and the effect of weight loss and weight-loss interventions in IIH. References were identified by searching PubMed with the terms idiopathic intracranial hypertension and weight loss. Additional citations were found in the identified references.

RESULTS

Over 90% of IIH patients are obese or overweight. The risk of IIH increases as a function of body mass index (BMI) and weight gain over the preceding year. The risk of IIH-induced vision loss also increases with increasing BMI, especially with BMI >40 kg/m. Several mechanisms have been proposed linking obesity to the development of IIH but the pathophysiology remains unknown. Published studies and clinical observations strongly support weight loss as an effective treatment, although there are no prospective controlled trials. Weight loss in the range of 6%-10% often leads to IIH remission. Weight loss of ≥5% at 1 year is achieved in roughly 50%-70% of patients if they are enrolled in a high-intensity lifestyle modification program and in 20%-35% of patients if they direct their own weight loss. Weight is typically regained over 1-3 years but about a third of patients maintain ≥5% weight loss over the long term. Patients treated initially with lifestyle modification therapy show a modest persisting benefit over self-directed patients. Selected commercial weight loss programs also may improve long-term maintenance of weight loss. New antiobesity drugs significantly improve the proportion of obese patients who have ≥5% loss of weight at 1 year.

CONCLUSIONS

Obesity is an important contributing factor for the development of IIH, although the pathophysiological mechanism linking obesity to IIH is unknown. The risk of developing IIH and associated visual loss increases with increasing BMI. Weight loss is an effective treatment for IIH. Long-term maintenance of initial weight loss is helped modestly by lifestyle modification programs and possibly by selected commercial weight loss programs. New antiobesity drugs may provide further options for IIH therapy in the future.