Effectiveness of Structured Education Programmes on Diet and Exercise for Preventing Type 2 Diabetes in Adults With Prediabetes: A Systematic Review.

Diet and exercise can prevent or delay progression from prediabetes to type 2 diabetes mellitus, but lifestyle advice in routine care may be brief, inconsistent, or unstructured. This systematic review assessed whether structured education programmes on diet and exercise are more effective than usual care, standard advice or less intensive lifestyle intervention in preventing or delaying type 2 diabetes among adults with prediabetes. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance and registered in PROSPERO (CRD42023484038). CINAHL (Cumulative Index to Nursing and Allied Health Literature), Embase, Ovid MEDLINE, Web of Science and Google Scholar were searched for English-language studies from database inception to July 2026. Randomised and cluster-randomised controlled trials involving adults with prediabetes, impaired glucose tolerance, or impaired fasting glucose were included if they compared structured education focused on diet, exercise or both with usual care, standard advice or a less intensive intervention. Data were synthesised narratively. Eighteen randomised or cluster-randomised controlled trials met the inclusion criteria. Most studies reported favourable effects of structured education on diabetes incidence, glycaemic indices and weight-related outcomes compared with usual care or less intensive lifestyle advice, while effects on cardiovascular risk markers were less consistent. Structured education on diet and exercise appears more effective than usual care or less intensive lifestyle advice in preventing or delaying type 2 diabetes among adults with prediabetes.