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When governments and healthcare providers offer people cash rewards for weight loss, an assumption is that cash rewards are versatile, working equally well for everyone – for example, for all genders. No research to date has tested for gender difference in response to financial incentives for weight loss. We show in an randomized controlled trial (RCT) (n = 472) that cash incentives for weight loss only worked for males. The RCT consisted of a 3-month, self-administered online weight loss program. Offering a US$150 incentive for a 5% weight loss more than tripled the proportion of males who were successful, compared with a no-incentive Control arm (20.9% vs. 5.9%). On average, males in the incentive arm lost 2.4% of weight over 3 months, compared with 0.9% in the Control arm. The same incentive had no such effect on females: The average weight loss in the incentive arm was not significantly different than in the Control (1.03% and 1.44%, respectively), nor was the proportion of participants meeting the 5% weight loss goal (8.6% and 8.7%, respectively). This study shows that males respond better than females to financial incentives for weight loss.

Background: Metabolic-bariatric surgery (MBS) leads to durable weight loss and significant metabolic improvement in type 2 diabetes mellitus (T2DM) patients with obesity. However, data on durability of control is often lacking in Asia. Aim: We report 5-year glycemic and metabolic outcomes in a T2DM cohort who had MBS from 2008-2012 at a tertiary center in Singapore. Methodology: Patient demographics and biochemical parameters were retrieved from a web-based data repository. DM remission was defined as HbA1c ≤6% without DM medications. Results: There were 59 patients with a mean age of 43.0±9.5 years and 37.3% were males (Table 1). Most (76.3%) had gastric bypass while 23.7% had sleeve gastrectomy. Baseline mean weight and BMI were 114.4±27.4 kg and 42.5±10.5 kg/m2 respectively. Mean weight loss of 26% was achieved at 1 year and sustained over 5 years. Mean HbA1c decreased from 8.3% to 5.8% and 6.3% at 1 and 5 years respectively, with use of fewer DM, anti-hypertensive and lipid-lowering medications. At 5 years, 18 of 43 (41.9%) patients achieved sustained remission of diabetes with 6 (14.0%) having relapse of DM after initial remission at 1 year. Conclusion: MBS is effective therapy for obesity and DM with durable glycemic and metabolic control associated with lower medication use over 5 years in this Asian population.Table 1. Characteristics of subjects at baseline and over 5-year follow upPatient characteristicsPre-surgery (n=59)12 months (n=47)24 months (n=40)36 months (n=37)48 months (n=38)60 months (n=43)GenderMaleFemale22(37.3%)37(62.7%)NANANANANAAge (years)43.0 ± 9.5NANANANANAEthnicityChineseMalayIndianOther24 (40.7%)20 (33.9%)14 (23.7%)1 (1.7%)NANANANANADiabetes mellitus duration (months)92.1±96.3NANANANANATypes of surgerySleeve gastrectomyMini gastric bypassRoux-en-Y gastric bypass14(23.7%)16(27.1%)29(49.2%)NANANANANAWeight (kg)114.4±27.484.9±20.5*84.5±21.0*87.5±23.0*83.0±19.9*83.8±21.5*Body Mass Index (BMI) (%)42.5±10.531.9±8.3*31.3±7.4*32.5±8.2*31.3±8.06*32.0±8.67*Systolic blood pressure (mmHg)127.0±14.6125.6±17.3125.8±18.2130.2±17.7129.7±13.3135.4±19.2Diastolic blood pressure (mmHg)77.0±9.577.5±11.878.3±10.880.5±8.778.8±10.775.8±8.7Fasting blood glucose (mmol/L)8.51±3.125.51±1.93*5.99±2.11*6.59±2.57*6.72±2.51*6.73±2.55*HbA1c (%)8.32±1.385.82±0.82*6.09±1.09*6.51±1.31*6.53±1.11*6.32±1.02*Lipid panel (mmol/L)Total cholesterolLDLTriglycerideHDL4.56±0.882.75±0.811.69±0.741.05±0.264.77±0.942.83±0.611.19±0.56*1.32±0.29*4.81±0.77*2.84±0.731.30±0.51*1.46±0.54*4.79±0.86*2.78±0.701.42±0.68*1.37±0.32*4.54±0.912.52±0.801.41±0.76*1.38±0.28*4.17±0.522.28±0.451.30±0.70*1.30±0.28*Number of DM medications1.90±1.030.42±0.79*0.31±0.68*0.45±0.93*0.57±1.10*0.60±1.19*Antihypertensive medications1.64±1.210.42±0.70*0.39±0.72*0.37±0.79*0.40±0.83*0.45±0.95*Lipid-lowering medications0.81±0.570.17±0.38*0.25±0.44*0.31±0.50*0.27±0.49*0.33±0.51*Diabetes remission (n)NA2824121218Continuous data as mean ± SD; categorical data as n (%)* Presence of significant difference when compared to pre-surgery data (p<0.05) Disclosure Z. Liew: None. A. Maung: None. S. Ganguly: Advisory Panel; Self; Novo Nordisk Inc.. P. Lee: None. K. Tham: None.