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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.
Watson, NA, Dyer, KA, Buckley, JD, Brinkworth, GD, Coates, AM, Parfitt, G, Howe, PRC, Noakes, M, Murphy, KJ
Nutrition journal. 2018;17(1):62
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The psychological burden of living with type 2 diabetes (T2D) has far reaching effects, negatively impacting quality of life, physical health and emotional wellbeing. It has been suggested that health-related quality of life (HRQoL) changes in response to weight status however this has not yet been explored in individuals with T2D. The aim of this randomised controlled study was to compare the effects of high protein and high carbohydrate diets, combined with moderate intensity exercise, on psychological wellbeing and HRQoL in 61 overweight adults with T2D. Participants enrolled in a 12-week weight loss period followed by a 12-week weight maintenance phase and blood glucose levels and various quality of life factors were assessed. This trial found in overweight adults with T2D, improvements in several psychological wellbeing and HRQoL were seen in response to modest weight loss and improvements in blood sugar levels. Improvements were seen in both high protein and high carbohydrate group, though a high protein diet may be better for maintaining control of blood glucose levels thus improving feelings of vitality. Based on this study, the authors conclude that it is imperative to address and support the psychological aspects of patients managing T2D.
Abstract
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.
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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.
Watson, NA, Dyer, KA, Buckley, JD, Brinkworth, GD, Coates, AM, Parfitt, G, Howe, PRC, Noakes, M, Murphy, KJ
Nutrition research (New York, N.Y.). 2018;:56-66
Abstract
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.
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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.
Watson, NA, Dyer, KA, Buckley, JD, Brinkworth, GD, Coates, AM, Parfitt, G, Howe, PRC, Noakes, M, Dye, L, Chadwick, H, et al
Contemporary clinical trials. 2015;(Pt B):217-225
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Abstract
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.