Evaluating a meal replacement program for accelerated weight loss and greater program retention.

INTERVENTION: Modified Meal Replacement Program (M‐MRP): The M‐MRP group will alternate between MF (3 days/week; Monday, Wednesday, Friday) and the Standard‐MRP (3 days/week; Tuesday, Thursday, Sunday), with one day where participants can eat freely, i.e. ad libitum (Saturday). On the MF days, participants will consume 2 Impromy meal replacement shakes (1000kJ each) and a ‘meal’ of free vegetables. Participants will follow this intervention for 16 weeks. Compliance will be collected in week 1, 4, 8, 12, 16 using 7‐day checklists. Participants will be required to mark yes/no to consumption of the allocated number of meal replacements, snacks, evening meal and the approximate number of cups (to the nearest half cup) of free vegetables consumed. Intake on the ad libitum day will not be assessed. Qualified research dietitians will deliver face to face instructions and support at baseline, week 1 (via telephone) 2,4,6,8,10,12, and 14. All participants will then be instructed by the study dietitians to follow an 8 week weight maintenance program based on the Live Well Plan (http://www.beefandlamb.com.au/Learn/Online_magazines/The_Live_Well_Plan). CONDITION: Overweight and obesity Weight loss PRIMARY OUTCOME: Participant retention in the weight loss program/study, assessed as the final recorded clinic attendance. weight loss assessed using calibrated digital scales SECONDARY OUTCOME: 5 validated visual analogue scales will be used to assess food cravings Advanced glycation end products assessed by auto fluorescence (AF) in human skin. Blood pressure assessed by digital sphygmomanometer Body composition of fat and lean mass via DEXA and Bioelectric Impedance (BIA) Compliance with the dietary protocols will be assessed using 7‐day checklists. Participants will be required to mark yes/no to consumption of the allocated number of meal replacements, snacks, evening meal and the approximate number of cups (to the nearest half cup) of free vegetables consumed (collected in week 1,4,8,12 and 16). DNA biomarkers from whole blood and buccal cells: genetic variants associated with weight loss (Published genetic variants which show a strong association with obesity and/or metabolic disfunction will be genotyped using assays targeted to specific sites (Sequenom or similar) and SNP arrays) and methylation status. Gut comfort using a survey designed for this study. ; fasting blood samples for C reactive protein using commercially available assay kits ; fasting blood samples for LDL cholesterol using commercially available assay kits ; fasting blood samples for total cholesterol, using commercially available assay kits ; fasting plasma glucose using commercial assay kits ; ; fasting, plasma levels of folic acid in erythrocytes, assessed by commercial laboratory service provider. fasting, plasma levels of zinc assessed by commercial laboratory service provider. fasting, plasma levels of iron assessed by commercial laboratory service provider. fasting, plasma levels of vitamin B12 assessed by commercial laboratory service provider. fasting, plasma levels of vitamin B1assessed by commercial laboratory service provider. fasting, plasma levels of vitaminD3/25‐OH calciferol assessed by commercial laboratory service provider. fecal markers of gut health (microbiome, SCFA, fecal moisture and pH, intestinal permeability) plasma insulin will be measured using commercial assay kits INCLUSION CRITERIA: 1.Adults with a BMI greater than or equal to 27kg/m2; 2.Aged 25‐60 years; 3.Willing to attend CSIRO SAHMRI clinic in Adelaide on 10 occasions; 4.Willing to participate in the study including collection of blood samples on 2 occasions, and completing questionnaires, 5.Willing to follow a weight loss dietary protocol for 16 weeks plus weight maintenance dietary protocol a further 8 weeks; ; Health related quality of life will be assessed using the validated The RAND‐36 and cohort‐term and working memory and speed of processing will be assessed using a short battery of validated tests (5‐10 minutes) that can be administered via a computer or tablet. Motivation and behavioural control will be assessed using 7 questions, which are based on the Theory of Planned Behaviour, mood will be assessed using the validated 20‐item Positive and Negative Affect Schedule, social problem solving inventory, plan quality and dichotomous thinking will be assessed using the validated 15‐item Dichotomous Thinking Inventory (DTI), the Social Problem Solving Inventory‐Revised and a modified version of the 7‐item Goal‐Setting Evaluation Tool for Diabetes (GET‐D). Retinal vascularity as a marker of metabolic health, assessed by retinal scan The Dutch Eating Behaviour Questionnaire (DEBQ) will assess eating styles. fasting blood samples for HDL cholesterol using commercially available assay kits 6. Non‐smoker; 7. Has been weight stable (i.e. less than 3 kg weight loss) for the past 2 months.