Multi-modal interventions outperform nutritional or exercise interventions alone in reversing metabolic syndrome: a systematic review and network meta-analysis

This review aimed to evaluate the comparative effectiveness of primary prevention interventions targeting therapeutic lifestyle changes on metabolic syndrome reversal and cardiometabolic outcomes in adults (≥ 18 years) with metabolic syndrome. A systematic search was conducted in seven electronic databases from inception to 28 April 2023 to identify randomised controlled trials (RCTs) of primary prevention interventions combating metabolic syndrome. Bayesian network meta-analyses were conducted to evaluate comparative effectiveness of active intervention components. Total of 98 eligible RCTs involving 12 813 participants were included. The individual interventions were categorised as nutritional or exercise interventions and their combinations as multi-modal interventions. The behavioural change strategies were categorised according to the sources of behaviour (i.e., capability, opportunity and motivation). Pairwise meta-analysis demonstrated that multi-modal interventions outperformed exercise interventions in reversing metabolic syndrome. Network meta-analyses revealed the differences in the optimal active intervention components across outcomes. The consumption of a diet promoting moderate macronutrient intake (caloric restriction, DASH and Mediterranean diets) combined with supervised aerobic exercise training or professional physical activity advice or counselling consistently yielded superior beneficial effects on metabolic syndrome, which was supported by a low certainty of evidence. Between-study differences in body weight and blood pressure were significantly explained by the use of behavioural change strategies. Combining a moderate macronutrient diet with aerobic exercise training or physical activity advice or counselling demonstrated superior beneficial effects on metabolic syndrome and its defining characteristics. These findings could provide healthcare professionals with critical guidance for implementing lifestyle interventions to manage metabolic syndrome.