James Lind Alliance research priorities: should diet and exercise be used as an alternative to drugs for the management of type 2 diabetes or alongside them?

AIM: To review evidence on whether diet and exercise should be used as an alternative to drug therapy for the management of type 2 diabetes or alongside. METHOD: We present a narrative review that draws on evidence from other systematic reviews and meta-analyses, narrative reviews, trials and cohort studies. We focused mainly on glycaemic control rather than control of blood pressure or cholesterol. RESULTS: Good-quality dietary advice that results in weight loss of >5% and physical activity interventions of >150 min/week of moderate to vigorous physical activity, combined with resistance exercise, can produce improvements in HbA1c similar to those produced by the addition of glucose-lowering drugs. These improvements can be seen at all stages of the disease. There are recognized interactions between glucose-lowering drugs and physical activity which may not be synergistic, but these are not well understood, and it is not clear if they are considered in clinical practice. Studies that explicitly compare drugs with diet or physical activity or control for drug use found that lifestyle could delay or reduce medication use, but most people eventually needed to progress to drug treatment. There are few studies, however, that provide strategies for the long-term maintenance of weight loss or physical activity. CONCLUSION: Diet and physical activity are of key importance in type 2 diabetes management, and attention to them improves glycaemic control and cardiovascular disease risk, but it is not yet known whether maintained lifestyle changes provide an alternative to drug therapy in the long term.

A systematic review of brief dietary questionnaires suitable for clinical use in the prevention and management of obesity, cardiovascular disease and type 2 diabetes.

The aim of this systematic review was to identify and describe brief dietary assessment tools suitable for use in clinical practice in the management of obesity, cardiovascular disease and type 2 diabetes. Papers describing development of brief (<35 items) dietary assessment questionnaires, that were accessible, simple to score and assessed aspects of the diet of relevance to the conditions of interest were identified from electronic databases. The development of 35 tools was described in 47 papers. Ten tools assessed healthy eating or healthy dietary patterns, 2 assessed adherence to the Mediterranean diet, 18 assessed dietary fat intake, and 5 assessed vegetable and/or fruit intake. Twenty tools were developed in North America. Test-retest reliability was conducted on 18 tools; correlation coefficients for total scores ranged from 0.59 to 0.95. Relative validation was conducted on 34 tools. The most common reference variable was percentage energy from fat (15 tools) and correlation coefficients ranged from 0.24, P<0.001 to 0.79, P<0.002. Tools that have been evaluated for reliability and/or relative validity are suitable for guiding clinicians when providing dietary advice. Variation in study design, settings and populations makes it difficult to recommend one tool over another, although future developers can enhance the understanding and use of tools by giving clear guidance as to the strengths and limitations of the study design. When selecting a tool, clinicians should consider whether their patient population is similar in characteristics to the evaluation sample.

Dietary changes and associations with metabolic improvements in adults with type 2 diabetes during a patient-centred dietary intervention: an exploratory analysis.

OBJECTIVES: Describe dietary intake of participants enrolled in a non-prescriptive dietary intervention and dietary changes at 6 months and explore whether these changes had a role in observed improvements in glycated haemoglobin (HbA1c), weight, lipids and blood pressure. DESIGN: Secondary analysis of data from the Early ACTivity in Diabetes randomised controlled trial. PARTICIPANTS: 262 patients with newly diagnosed type 2 diabetes randomised to the dietary intervention. OUTCOMES AND ANALYSIS: Changes in energy intake, macronutrients, fibre and alcohol and in weight, waist circumference, lipids, HbA1c and blood pressure at baseline and 6 months. Multivariate models were used to examine associations between dietary changes and metabolic variables. RESULTS: Men reported reducing mean energy intake from 1903±462 kcal to 1685 kcal±439 kcal (p<0.001), increasing carbohydrate intake from 42.4±6.6% to 43.8±6.6% (p=0.002) and reducing median alcohol intake from 13 (0-27) g to 5 (0-18) g (p<0.001). Women reported reducing mean energy intake from 1582±379 kcal to 1459±326 kcal (p<0.001) with no change to macronutrient distribution and alcohol. Fibre intake was maintained. In men (n=148), weak and clinically insignificant associations were found between increased carbohydrates and reduction in HbA1c (ß=-0.003 (-0.006, -0.001); p=0.009), increased fibre and reduction in total cholesterol (ß=-0.023 (-0.044, -0.002); p=0.033), decreased total fat and reduction in low-density lipoprotein (LDL)-cholesterol (ß=0.024 (0.006, 0.001); p=0.011), and decreased alcohol and reduction in diastolic blood pressure (ß=0.276 (0.055, 0.497); p=0.015). In women (n=75), associations were found between a decrease in transfats and reductions in waist circumference (ß=-0.029 (0.006, 0.052); p=0.015), total cholesterol (ß=0.399 (0.028, 0.770); p=0.036) and LDL cholesterol (ß=0.365 (0.042, 0.668); p=0.028). CONCLUSIONS: Clinically important metabolic improvements observed in a patient-centred dietary intervention were not explained by changes in macronutrients. However, a non-prescriptive approach may promote a reduction in total energy intake while maintaining fibre consumption. TRIAL REGISTRATION NUMBER: The Early ACTID trial number ISRCTN92162869.

Changes in reported food intake in adults with type 2 diabetes in response to a nonprescriptive dietary intervention.

OBJECTIVES: There is a lack of published data about the food intake of patients with type 2 diabetes and the changes that they make in response to patient-centred dietary advice. The present study describes the changes reported in response to a nonprescriptive dietary intervention based upon UK dietary guidelines. METHODS: Two hundred and sixty-two patients (87 women and 175 men) from the Early ACTivity in Diabetes (ACTID) trial who received the dietary intervention returned 4 days food diaries at baseline and 6 months. Nonparametric tests were used to examine changes in meal patterns, total energy intake and energy from food groups between baseline and 6 months. RESULTS: Mean (SD) number of reported meals day(-1) was 3.0 (0.3) and mean (SD) number of snacks was 1.1 (0.6) at both baseline and 6 months for men and women. Men reported decreasing energy intake by a mean (SD) of 912 (1389) KJ/day [218 (332) kcal day(-1) ] (P < 0.001) and women by 515 (1130) KJ/day [123 (270) kcal day(-1) ] (P < 0.001). Men reported reducing energy from alcoholic drinks [-234 (527) KJ day(-1) ; P < 0.001], white bread [-113 (402) KJ day(-1) ; P = 0.001], biscuits [i.e. cookies -67 (205) KJ day(-1) ; P < 0.001] and cakes [-50 (410) KJ day(-1) ; P = 0.0012]. Women reported reducing energy from mixed main meals [-134 (456) KJ day(-1) ; P = 0.036], pasta and rice [-79 (326) KJ day(-1) ; P = 0.019], high-energy drinks [-59 (159) KJ day(-1) ; P = 0.001] and white bread [-59 (368) KJ day(-1) ; P = 0.042]. CONCLUSIONS: Men and women in the Early ACTID study reported small changes in higher-energy and lower-fibre foods and drinks in response to patient-centred dietary advice.

Diet or diet plus physical activity versus usual care in patients with newly diagnosed type 2 diabetes: the Early ACTID randomised controlled trial.

BACKGROUND: Lifestyle changes soon after diagnosis might improve outcomes in patients with type 2 diabetes mellitus, but no large trials have compared interventions. We investigated the effects of diet and physical activity on blood pressure and glucose concentrations. METHODS: We did a randomised, controlled trial in southwest England in adults aged 30-80 years in whom type 2 diabetes had been diagnosed 5-8 months previously. Participants were assigned usual care (initial dietary consultation and follow-up every 6 months; control group), an intensive diet intervention (dietary consultation every 3 months with monthly nurse support), or the latter plus a pedometer-based activity programme, in a 2:5:5 ratio. The primary endpoint was improvement in glycated haemoglobin A(1c)(HbA(1c)) concentration and blood pressure at 6 months. Analysis was done by intention to treat. This study is registered, number ISRCTN92162869. FINDINGS: Of 593 eligible individuals, 99 were assigned usual care, 248 the diet regimen, and 246 diet plus activity. Outcome data were available for 587 (99%) and 579 (98%) participants at 6 and 12 months, respectively. At 6 months, glycaemic control had worsened in the control group (mean baseline HbA(1c) percentage 6·72, SD 1·02, and at 6 months 6·86, 1·02) but improved in the diet group (baseline-adjusted difference in percentage of HbA(1c) -0·28%, 95% CI -0·46 to -0·10; p=0·005) and diet plus activity group (-0·33%, -0·51 to -0·14; p<0·001). These differences persisted to 12 months, despite less use of diabetes drugs. Improvements were also seen in bodyweight and insulin resistance between the intervention and control groups. Blood pressure was similar in all groups. INTERPRETATION: An intensive diet intervention soon after diagnosis can improve glycaemic control. The addition of an activity intervention conferred no additional benefit. FUNDING: Diabetes UK and the UK Department of Health.

Advice available on the Internet for people with coeliac disease: an evaluation of the quality of websites.

BACKGROUND: The Internet may be a useful resource for people with coeliac disease as a great deal of health-related information is published online. However, not all of it is accurate. It has been suggested that accurate information is most likely found on transparent sites and kitemarks are awarded on this basis. This paper examines whether the Internet is a useful resource for people with coeliac disease and whether transparency criteria can be used in identifying accurate sites. METHOD: An evaluation tool was developed using selected transparency criteria and clinical guidelines for accuracy. A total of 63 websites were evaluated. RESULTS: In the study, 66% of the websites scored less than 50% for accuracy. This was primarily because of incomplete information but 15.9% of sites contained inaccuracies. Over 50% of sites scored less than 50% for transparency. No correlation was found between sites that scored highly for accuracy and those that scored highly for transparency. CONCLUSION: There are useful information available for people with coeliac disease but transparency criteria alone cannot be used to identify accurate sites.