Effects of resistance training and animal protein intake on diet–induced weight loss in obese older women displaying metabolic abnormalities

INTERVENTION: All groups will be followed for 24 weeks (4 weeks of weight stabilisation before and after the intervention + 16 weeks of weight loss program). Women will be randomized to one of the four following groups: 1. Standard hypocaloric diet 2. Standard hypocaloric diet + resistance training 3. Standard hypocaloric diet + animal proteins supplement and 4. Standard hypocaloric diet + animal proteins supplement + resistance training Standard hypocaloric diet: This diet should induce an average caloric deficit between 500 and 1000 kcal/day (weight loss between 1 and 2 lbs per week). The diet will be based on the Canadian food guide (15% of proteins, 30% of lipids and 50% of carbohydrates). The average daily protein intake should be 0.8 gram per kg of body weight. Animal proteins supplement: Subjects will be asked to consume a supplement of 25 grams of animal proteins each day. For those in the resistance training group, the supplement will be taken within 2 hours after training on day of training. Resistance training (RT): Women in RT groups will train three times a week on non‐consecutive days, under the supervision of an exercise physiologist. All training sessions will start with a warm‐up period consisting of 5 min of low‐intensity cycling. Participants then performed the load phase of RT consisting in 3 series of 8 repetitions for nine different exercises. CONDITION: Obesity, menopause, metabolic syndrome, physical capacity. ; Nutritional, Metabolic, Endocrine ; Obesity PRIMARY OUTCOME: 1. Dual energy X‐ray absorptiometry (DXA) technology to measure total fat mass, bone mass and lean body mass as well as each tissue by region (trunk, legs and arms). ; 2. Other measures of body composition include weight, height, waist and hip circumferences. They are taken before, during and after the intervention (total of 3 times for DXA outcomes and 8 times for other body composition measurements). SECONDARY OUTCOME: 1. Lipids, glucose homeostasis, inflammation profile, adipokines, energy expenditure, resting arterial blood pressure and heart rate, physical capacity and psychosocial determinants; 2. Plasma measures will be taken before, during and after the intervention (total of 3 times): Analyses will be done on the COBAS INTEGRA 400 (Roche Diagnostic, Montréal, Canada) analyzer for total cholesterol, HDL‐cholesterol, triglycerides and glucose combined with specific cassettes containing in vitro diagnostic reagent system. LDL‐cholesterol concentration will be calculated by Friedewald equation using total cholesterol, HDL‐cholesterol and triglycerides. ; 2.1. Insulin and IGF‐I concentrations will be determined with commercially available radioimmunoassay kits (Radioassay System Laboratory, and ICN Biomedicals, Costa Mesa, CA; distributed by Immunocorp, Montreal, PQ, and Diagnostic Systems aboratories‐2900, respectively). ; 2.2. Plasma IGFBP‐1,2,3 will be determined by Western blotting. ; 2.3. Serum adiponectin and leptin (Linco Research, St‐Charles, MO, USA) levels will be measured in duplicate with a commercial radioimmunoassay (RIA) procedure using 125I‐labeled bioactive human adiponectin and leptin as tracers and a rabbit polyclonal antibody raised against full‐length peptides. ; 2.4. Plasma immunoreactive total and acylated ghrelin levels will be measured in duplicate with a commercial RIA using 125I‐labeled bioactive human acylated ghrelin as tracers and rabbit polyclonal antibody raised against full‐length total ghrelin and against the Ser3‐octanoylated portion of acylated ghrelin, respectively (Linco Research, St. Charles, MO). ; 2.5. Nonacylated ghrelin values will be calculated as total minus acylated ghrelin. NPY will be measured by RIA kits (Peninsula Lab., Belniont, CA) after plasma extraction on reverse‐phase minicolunins. CRP will be measured using an enzyme‐linked immunosorbent assay based on purified protein and polyclonal anti‐CRP antibodies (sensitivity: 0.08 µg/ml and interassay coefficient of variation: 8.0%) (Calbiochem, San Diego, CA). ; 2.6. An ELISA will be used to measure IL‐6, using commercial kits (detectable limit: 0.10 pg/ml and interassay coefficient of variation: 10.3%) (Quantikine, Minneapolis, MN, USA). Values will be measured in duplicate, and the average will be reported for both assays. Other metabolic variables for screening will be follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), HBA1c, creatinin, haptoglobin and Sex hormone‐binding globulin (SHBG).; 3. Glucose homeostasis will be measured before and after the intervention (total of 2 times). A 75g oral glucose tolerance test (OGTT) will be performed in the morning after a 12‐hour fast, as recommended. Blood samples will be collected through a venous catheter from an antecubital vein in vacutainer tubes containing Trasylol (Miles, Rexdale, Ontario, Canada) and EDTA, at ‐15, 0, 15, 30, 45, 60, 90 and 120 minutes. Plasma insulin concentrations will be determined by radioimmunoassay using polyethylene glycol separation and glucose levels will be measured enzymically.; 4. Measures of energy expenditure include the resting metabolic rate (RMR) and the metabolic cost of walking at different paces, both measured by indirect calorimetry. Measurement of gas concentrations will be used to determine 24h RMR using the equation of Weir. These measures will be taken before, during and after the intervention (total of 2 times).; 5. Resting systolic and diastolic blood pressures and heart rate will be measured in sitting position. First, resting values for each visit will be determined as the average of the last four readings of five (one per min) from a Dinamap (Critikon, Johnson & Johnson, Tampa, FL) automatic machine. Measurements will be performed at different visits before, during and after the intervention (total of 8 times). An appropriate cuff size will be selected for each subject based on arm circumference; 6. Physical capacity measures include climbing stairs, standing on one leg, hand grip strength and the 6‐min walk test. These measures will be taken before and after the intervention (2 times); 7. Following questionnaires are used to measure psychosocial determinants: ; 7.1. Self‐Efficacy ; 7.2. Perceived Benefits; 7.3. Mendelson et al?s Body Esteem Scale; 7.4. Medical Outcome Survey Quality of Life Questionnaire; 7.5. Stunkard & Messick?s 3‐Factor Eating Questionnaire; 7.6. Diet History Questions; 7.7. Menopause rating scale INCLUSION CRITERIA: 1. Women will be included in the study if they had stopped menstruating for more than 1 yr, and if they have follicle stimulating hormone (FSH) levels > 30 U/L 2. Aged between 60 and 75 years old 3. Body mass index (BMI) between 27 and 40 kg/m2 4. Sedentary (< 2 times a week of exercise) 5. Non‐smokers 6. Low to moderate alcohol consumers (< 2 drinks/week) 7. Displaying at least one of the following factor of the metabolic syndrome accordingly to the Adult Treatment Panel III (ATP III?s) definition [63] [triglycerides > 1.70 mmol/L; high density lipoprotein (HDL)‐cholesterol < 1.29 mmol/L; resting blood pressure < 160/95 mmHg (treated or not); fasting plasma glucose > 6.1 mmol/L], 7) stable medication(s) for the metabolic syndrome since 6 weeks and 8. Glycated haemoglobin (HbA1c) < 8%