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.

Nerylee Ann Watson, Kathryn Ann Dyer, Jonathan David Buckley, Grant David Brinkworth, Alison Mary Coates, Gaynor Parfitt, Peter Ranald Charles Howe, Manny Noakes, Karen Joy Murphy

Journal: Nutrition journal 2019;17(1):62

PMID: 29907153

Plain Language Summary

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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/m, 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.

Address: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA, 5001, Australia. [email protected].; Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA, 5001, Australia.; Commonwealth Scientific and Industrial Research Organization - Health and Biosecurity, PO Box 10041, Adelaide, SA, 5000, Australia.; Clinical Nutrition Research Centre, School of Biomedical Sciences and Pharmacy, University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia.; Institute for Resilient Regions, University of Southern Queensland, Springfield, QLD, 4300, Australia.
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