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Evidence summaries

Dietary Advice and Exercise for Type 2 Diabetes Mellitus

Dietary advice combined with exercise improves metabolic control in type 2 diabetes mellitus in adults. Level of evidence: "A"

Exercise and dietary advice is recommended for all patients with type 2 diabetes as a non-pharmacological treatment.

A systematic review and meta-analysis 2 included 20 studies with a total of 1 192 subjects. Combined aerobic exercise and diet (AEDT) produced significant improvements in glycated hemoglobin (standardised mean difference -0.52, 95 % CI -0.93 to -0.10), body mass index, body weight, waist circumference, systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, fasting blood glucose, fasting plasma insulin, glycated hemoglobin, leptin, interleukin-6, C-reactive protein, and adiponectin (p < 0.05) compared to the standard treatment (ST) group.

A Cochrane review [Abstract] 1 included 18 studies with a total of 1 467 subjects. Dietary approaches included low-fat/high-carbohydrate diets, high-fat/low-carbohydrate diets, low-calorie (1000 kcal per day) and very-low-calorie (500 kcal per day) diets and modified fat diets. Dietary advice plus exercise as compared with dietary advice alone (6 trials, n=340), was associated with a statistically significant mean decrease in glycated haemoglobin at 6 months (pooled weighted mean difference, WMD 0.9%, 95% confidence interval 0.4 to 1.3) and at twelve months (WMD 1.0%, 95% CI 0.4 to 1.5). However, all studies were at high risk of bias. No data were found on micro- or macrovascular diabetic complications, mortality or quality of life.

A meta-analysis 3 assessing associations of structured exercise training in type 2 diabetes included 47 RCTs with 8538 patients. Structured exercise (aerobic, resistance, or combined) decreased HbA1c (-0.67%, 95% CI -0.84% to -0.49%; 23 trials) compared with control. Declines in HbA1c compared with control were -0.73% (95% CI -1.06% to -0.40%) in structured aerobic exercise; -0.57% (95% CI -1.14% to -0.01%) in structured resistance training; and -0.51% (95% CI -0.79% to -0.23%) in both combined. Structured exercise durations of more than 150 minutes per week were associated with HbA1c reductions of 0.89%, while structured exercise durations of 150 minutes or less per week were associated with HbA1c reductions of 0.36%. Combined physical activity advice and dietary advice was associated with decreased HbA1c (-0.58%; 95% CI -0.74% to -0.43%) as compared with control.

Another meta-analysis 4 assessing associations of structured exercise training (aerobic, resistance, or combined) in type 2 diabetes included 30 RCTs with 9540 patients. Exercise was associated with reductions in systolic blood pressure (SBP; WMD -4.22 mmHg; 95% CI -5.89 to -2.56) and diastolic blood pressure (DBP; WMD -2.07 mmHg; 95% CI -3.03 to -1.11) versus controls. Structured exercise longer than 150 min/week was associated with greater blood pressure reductions. Physical activity advice only was associated with reduction in SBP (WMD -2.97 mmHg; 95% CI -4.52 to -1.43) and DBP (WMD -1.41 mmHg; 95% CI -1.94 to -0.88) versus controls.

The following decision support rules contain links to this evidence summary:

References

  • Nield L, Moore HJ, Hooper L, Cruickshank JK, Vyas A, Whittaker V, Summerbell CD. Dietary advice for treatment of type 2 diabetes mellitus in adults. Cochrane Database Syst Rev 2007 Jul 18;(3):CD004097. [PubMed]
  • Al-Mhanna SB, Rocha-Rodriguesc S, Mohamed M, et al. Effects of combined aerobic exercise and diet on cardiometabolic health in patients with obesity and type 2 diabetes: a systematic review and meta-analysis. BMC Sports Sci Med Rehabil 2023;15(1):165[PubMed]
  • Umpierre D, Ribeiro PA, Kramer CK et al. Physical activity advice only or structured exercise training and association with HbA1c levels in type 2 diabetes: a systematic review and meta-analysis. JAMA 2011;305(17):1790-9. [PubMed]
  • Figueira FR, Umpierre D, Cureau FV et al. Association between physical activity advice only or structured exercise training with blood pressure levels in patients with type 2 diabetes: a systematic review and meta-analysis. Sports Med 2014;44(11):1557-72. [PubMed]

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