Comparing the effectiveness of general dietary advice versus a very low energy diet in an obese outpatient population in Australia.

PURPOSE: Obesity is a major public health burden. Outpatient clinics are an essential resource for individuals with obesity to access advice for weight loss management. The aim of this study was to compare anthropometric and weight loss outcomes between participants receiving general dietary (GD) advice, and those on a very low energy diet (VLED) under non-trial conditions. METHODS: Data from 276 adults with obesity attending a multidisciplinary weight management clinic were analysed. Changes in anthropometry, body composition, and blood pressure (BP) over 12 months were analysed using linear mixed-effects models. RESULTS: Males on the GD demonstrated statistically greater reductions in body weight (BW), BMI, percent fat mass (FM), systolic BP, waist and hip circumference (p < 0.01). Changes in males on a VLED did not reach significance. Females showed statistically significant reductions in BW, BMI, waist and hip circumference regardless of dietary intervention (p < 0.01); those on the GD significantly reduced percent FM (p < 0.001). Females on a VLED had statistically greater reductions in BW, BMI and systolic BP compared to those on the GD. No effect of exercise physiologist was observed in this study. Participants prescribed a GD attended for significantly longer than those on a VLED (p < 0.05), irrespective of gender. At 12 months, 14.3 and 4.5% of males and females on a VLED were still attending, compared to 10.6 and 4.5% on the GD. CONCLUSIONS: In this retrospective study, females in both dietary intervention groups achieved significant changes across multiple measures. Only men receiving GD advice demonstrated significant changes. LEVEL OF EVIDENCE: Level II-2.

Bile salt stimulated lipase: Inhibition by phospholipids and relief by phospholipase A2.

INTRODUCTION: Bile salt stimulated lipase (BSSL; Enzyme Commission (EC) number 3.1.1.13) has been a candidate triglyceridase for improving enzyme therapy for pancreatic insufficiency; however, its efficacy is near absent. We hypothesise that similarly to pancreatic lipase, BSSL is inhibited by phospholipids and this inhibition is relieved by Phospholipase A2 (PLA2; EC 3.1.1.4), and the present study was undertaken to explore this possibility. MATERIALS AND METHODS: Synthetic emulsions of triglyceride and phosphatidylcholine (PC) or lysophosphatidylcholine (LPC)/bile salt mixed micelles were used as a model of intestinal digestion-media. The effect of PLA2 treatment of systems containing PC on BSSL activity was also explored. Automatic titration at constant pH (pH-stat) and nuclear magnetic resonance (NMR) spectroscopy were used to measure the rate and identify products of lipolysis. RESULTS: PC was inhibitory to BSSL activity, while LPC became inhibitory only above an LPC/bile salt concentration ratio of 0.3. PLA2 treatment relieved the inhibition only below this ratio, despite its complete phospholipid-hydrolysing action. Thus, LPC had an inhibitory effect at higher concentrations. CONCLUSIONS: These results may implicate a change in the design of enzyme therapy in patients with pancreatic exocrine insufficiency. Supplementation of BSSL with PLA2 could improve patient health with adequate manipulation of phospholipid and lysophospholipid concentrations in the intestinal fluid.