Behaviour change techniques targeting both diet and physical activity in type 2 diabetes: A systematic review and meta-analysis.
Changing diet and physical activity behaviour is one of the cornerstones of type 2 diabetes treatment, but changing behaviour is challenging. The objective of this study was to identify behaviour change techniques (BCTs) and intervention features of dietary and physical activity interventions for patients with type 2 diabetes that are associated with changes in HbA1cand body weight.



We performed a systematic review of papers published between 1975-2015 describing randomised controlled trials (RCTs) that focused exclusively on both diet and physical activity. The constituent BCTs, intervention features and methodological rigour of these interventions were evaluated. Changes in HbA1cand body weight were meta-analysed and examined in relation to use of BCTs.



Thirteen RCTs were identified. Meta-analyses revealed reductions in HbA1cat 3, 6, 12 and 24 months of -1.11 % (12 mmol/mol), -0.67 % (7 mmol/mol), -0.28 % (3 mmol/mol) and -0.26 % (2 mmol/mol) with an overall reduction of -0.53 % (6 mmol/mol [95 % CI -0.74 to -0.32, P < 0.00001]) in intervention groups compared to control groups. Meta-analyses also showed a reduction in body weight of -2.7 kg, -3.64 kg, -3.77 kg and -3.18 kg at 3, 6, 12 and 24 months, overall reduction was -3.73 kg (95 % CI -6.09 to -1.37 kg, P = 0.002). Four of 46 BCTs identified were associated with >0.3 % reduction in HbA1c: 'instruction on how to perform a behaviour', 'behavioural practice/rehearsal', 'demonstration of the behaviour' and 'action planning', as were intervention features 'supervised physical activity', 'group sessions', 'contact with an exercise physiologist', 'contact with an exercise physiologist and a dietitian', 'baseline HbA1c>8 %' and interventions of greater frequency and intensity.



Diet and physical activity interventions achieved clinically significant reductions in HbA1cat three and six months, but not at 12 and 24 months. Specific BCTs and intervention features identified may inform more effective structured lifestyle intervention treatment strategies for type 2 diabetes.
Physiology, School of Medicine, NUI Galway, University Road, Galway, Ireland.|Electrical & Electronic Engineering, School of Engineering & Informatics, NUI Galway, University Road, Galway, Ireland.
Kevin A
KA
Cradock
Electrical & Electronic Engineering, School of Engineering & Informatics, NUI Galway, University Road, Galway, Ireland.|National Centre for Biomedical Engineering Science, NUI Galway, University Road, Galway, Ireland.
Gearóid
G
ÓLaighin
Bariatric Medicine Service, Galway Diabetes Research Centre, HRB Clinical Research Facility, Galway, Ireland.
Francis M
FM
Finucane
School of Health and Exercise Sciences, Faculty of Health and Social Development, The University of British Columbia, ART 129- 1147, Research Road, Kelowna, BC, V1V 1 V7, Canada.
Heather L
HL
Gainforth
Physiology, School of Medicine, NUI Galway, University Road, Galway, Ireland. leo.quinlan@nuigalway.ie.
Leo R
LR
Quinlan
School of Health and Exercise Sciences, Faculty of Health and Social Development, The University of British Columbia, ART 129-1147 Research Road, Kelowna, BC, V1V 1 V7, Canada.
Kathleen A Martin
KA
Ginis
D000328:Adult; D001521:Behavior Therapy / Q000379:methods*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000628:therapy*; D004032:Diet; D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008019:Life Style; D008297:Male
D006442:Glycated Hemoglobin
Behaviour change techniques; Diet; HbA1c; Meta-analysis; Physical activity; Systematic review; Type 2 diabetes