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?

Aims The aim is 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 focussed 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 >150mins/week moderate to vigorous physical activity combined with resistance exercise can produce improvements to HbA1c similar to that produced by the addition of glucose lowering drugs. These improvements can be seen at all stages of the disease. There are recognised 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 lifestyle could delay or reduce medication, but most people eventually needed to progress onto drug treatment. However, there are few studies that provide strategies for 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.