Comparison of two low-fat diets, differing in protein and carbohydrate, on psychological wellbeing in adults with obesity and type 2 diabetes: a randomised clinical trial.

BACKGROUND: Although higher-protein diets (HP) can assist with weight loss and glycemic control, their effect on psychological wellbeing has not been established. The objective of this study was to compare the effects of a HP and a higher-carbohydrate diet (HC), combined with regular exercise, on psychological wellbeing both during weight loss (WL) and weight maintenance phases (WM). METHODS: In a parallel RCT, 61 adults with T2D (mean ± SD: BMI 34.3 ± 5.1 kg/m2, aged 55 ± 8 years) consumed a HP diet (29% protein, 34% carbohydrate, 31% fat) or an isocaloric HC diet (21%:48%:24%), with moderate intensity exercise, for 12 weeks of WL and 12 weeks of WM. Secondary data evaluating psychological wellbeing was assessed using: Problems Areas in Diabetes (PAID); Diabetes-39 Quality of Life (D-39); Short Form Health Survey (SF-36); Perceived Stress Scale-10 (PSS-10) and the Leeds Sleep Evaluation Questionnaire (LSEQ) at Weeks 0, 12 and 24 and evaluated with mixed models analysis. RESULTS: Independent of diet, improvements for PAID; D-39 diabetes control; D-39 severity of diabetes; SF-36 physical functioning and SF-36 general health were found following WL (d = 0.30 to 0.69, P ≤ 0.04 for all) which remained after 12 weeks of WM. SF-36 vitality improved more in the HP group (group x time interaction P = 0.03). Associations were seen between HbA1c and D-39 severity of diabetes rating (r = 0.30, P = 0.01) and SF-36 mental health (r = - 0.32, P = 0.003) and between weight loss and PAID (r = 0.30, P = 0.01). CONCLUSION: Several improvements in diabetes-related and general psychological wellbeing were seen similarly for both diets following weight loss and a reduction in HbA1c with most of these improvements remaining when weight loss was sustained for 12 weeks. A HP diet may provide additional increases in vitality. TRIAL REGISTRATION: The trial was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12613000008729 ) on 4 January 2013.

Gastrointestinal symptom burden and dietary intake in patients with chronic kidney disease.

BACKGROUND: Gastrointestinal (GI) symptoms can present a significant burden to patients with chronic kidney disease (CKD) but the reported prevalence is inconsistent. OBJECTIVE: To examine the GI burden and dietary intake in patients with CKD with or without dialysis. METHODS: This was a cross-sectional study of 216 adults, recruited from outpatient and dialysis clinics, with CKD stage 4 or 5 not receiving dialysis (CKD-ND), or receiving haemodialysis (HD) or peritoneal dialysis (PD). Three questionnaires were administered: the Bristol Stool Form Scale (BSFS); a modified Gastrointestinal Symptom Rating Scale and a short Food Frequency Questionnaire. Outcomes were stool frequency and consistency, GI symptoms and dietary intake. RESULTS: Data were collected from 216 patients (mean age, 63 years [95% CI: 61, 65]; 63% males; CKD-ND: n = 134; HD: n = 67; PD: n = 15). Mean stool frequency for all groups was one bowel action per day (p = .45) and consistency was normal (BSFS type 4, p = .95). Overall GI symptom burden was low but several symptoms occurred at least "most of the time" including "tiredness/lethargy" (54% of participants), "reduced appetite" (29%), "early satiety" (25%) and "change in taste" (15%). Low intakes of fresh fruit, vegetables, whole-grains and legumes were found. No associations were observed between diet and GI symptoms. CONCLUSION: The overall GI symptom burden was low, but >15% of participants reported several symptoms as occurring most to all of the time. Low intakes of fresh fruit, vegetables, whole-grains and legumes were observed in all CKD patients.

Reductions in food cravings are similar with low-fat weight loss diets differing in protein and carbohydrate in overweight and obese adults with type 2 diabetes: A randomized clinical trial.

Food cravings are common in type 2 diabetes (T2D). Higher-protein diets are effective in improving satiety but their effect on cravings is unclear. It was hypothesized that a high protein (HP) diet would provide greater reductions in cravings than an isocaloric higher-carbohydrate diet (HC). In a randomized controlled trial, 61 adults (54% males) with T2D (means ± SD: BMI 34.3 ± 5.1 kg/m2; aged 55 ± 8 years) consumed either a HP diet (mean across study: 29% protein, 34% carbohydrate, 31% fat) or an isocaloric HC diet (21%:48%:24%) for 12-weeks each of weight loss (WL) and weight maintenance (WM). The Food Craving Inventory (FCI), measuring types of foods craved and the General Food Craving Questionnaires measuring traits (G-FCQ-T) and states (G-FCQ-S) were assessed at Weeks 0, 12 and 24. Weight changes were similar between groups (means ± SEM: WL: -7.8 ± 0.6 kg, WM: -0.6 ± 0.4 kg). No group effects or group x time interactions were found for any outcome (P ≥ .07). Independent of group, all food cravings (except carbohydrates) and G-FCQ-T subscales decreased over the 24-week study (P ≤ .04) with sweets and fast food cravings, loss of control and emotional cravings reducing following WL (P ≤ .03). Obsessive preoccupation with food decreased following both phases (WL: P = .03; WM: P = .001). Weight was associated with several FCI subscales (r ≥ 0.24, P ≤ .04). In conclusion, both the HP and HC diets provided significant reductions in food cravings after similar weight losses which were maintained when weight was stabilized.

Correction: Watson, N.; et al. Effects of Low-Fat Diets Differing in Protein and Carbohydrate Content on Cardiometabolic Risk Factors during Weight Loss and Weight Maintenance in Obese Adults with Type 2 Diabetes. Nutrients 2016, 8, 289.

The authors request the following corrections to their paper [...].

Effects of Low-Fat Diets Differing in Protein and Carbohydrate Content on Cardiometabolic Risk Factors during Weight Loss and Weight Maintenance in Obese Adults with Type 2 Diabetes.

Despite evidence for the benefits of higher-protein (HP) diets in weight loss, their role in type 2 diabetes mellitus (T2DM) management and weight maintenance is not clear. This randomised study compared the effects of a HP diet (38% carbohydrate, 30% protein, 29% fat) to a isocaloric higher-carbohydrate diet (HC: 53%:21%:23%) on cardiometabolic risk factors for 12 weeks in energy restriction (~30% reduction) followed by 12 weeks of energy balance whilst performing regular exercise. Outcomes were measured at baseline and the end of each phase. Sixty-one overweight/obese adults (BMI (body mass index) 34.3 ± 5.1 kg/m², aged 55 ± 8 years) with T2DM who commenced the study were included in the intention-to-treat analysis including the 17 participants (HP n = 9, HC n = 8) who withdrew. Following weight loss (M ± SEM: -7.8 ± 0.6 kg), there were significant reductions in HbA1c (-1.4% ± 0.1%, p < 0.001) and several cardiometabolic health risk factors. Improvements were sustained for 12 weeks when weight was stabilised and weight loss maintained. Both the HP and HC dietary patterns with concurrent exercise may be effective strategies for weight loss and weight maintenance in T2DM although further studies are needed to determine the longer term effects of weight maintenance.

A randomised trial comparing low-fat diets differing in carbohydrate and protein ratio, combined with regular moderate intensity exercise, on glycaemic control, cardiometabolic risk factors, food cravings, cognitive function and psychological wellbeing in adults with type 2 diabetes: Study protocol.

BACKGROUND: Hypocaloric low-fat diets, high in protein with moderate carbohydrate (HP) can enhance weight loss, improve glycaemic control and improve cardiometabolic health risk factors in type 2 diabetes mellitus (T2DM). However, it is unclear whether the metabolic benefits observed during weight loss are sustained during energy-balance and weight maintenance. Furthermore, there is a lack of evidence regarding the effect of HP diets on food cravings, cognitive function and psychological wellbeing in T2DM, despite carbohydrate food cravings, cognitive impairment and depression being associated with hyperglycaemia. METHODS/DESIGN: Overweight/obese adults with T2DM were randomised to consume either a HP diet (n=32, ~32% protein, 33% carbohydrate, 30% fat) or a higher-carbohydrate diet (HC, n=29, ~22% protein, 51% carbohydrate, 22% fat) for 24 weeks with 30 min of moderate intensity exercise five days/week for the study duration. There were 2 phases: a 12 week weight loss phase followed by a 12 week weight maintenance phase. Primary outcome was glycaemic control (glycosylated haemoglobin; HbA1c). Secondary outcomes were cardiometabolic risk factors (body composition, fasting blood pressure, blood lipids, glucose, insulin and C-reactive protein), food cravings, cognitive function (memory; psychomotor and executive function and psychological well-being. Outcomes were measured at baseline and the end of each 12-week intervention phase. Data will be analysed as intention-to-treat using linear mixed effects models. CONCLUSION: This study will examine the effects of two dietary interventions on health outcomes in T2DM during weight loss and notably following weight maintenance where there is a paucity of evidence.