A Systematic Review of the Long-Term Efficacy of Physical Activity Interventions in Reducing Risk Factors for Obesity in Adults

Regular physical activity (PA) provides numerous health advantages, including lowering mortality rates and preventing obesity. Despite well-established guidelines advising 150–300 minutes of moderate-intensity or 75–150 minutes of vigorous-intensity aerobic PA weekly, sedentary lifestyles remain prevalent, especially in industrialised nations. This systematic review examines the long-term effectiveness (12–24 months) of PA interventions aimed at reducing obesity risk among adults, with a particular focus on identifying strategies that promote sustained adherence. A comprehensive literature search was performed using multiple databases, including Cochrane Library, PubMed, and Embase, focusing on studies published between January 2004 and January 2024. The inclusion criteria focused on randomised controlled trials and similar designs targeting healthy adults, with interventions promoting sustained PA. Primary outcomes assessed were long-term PA adherence, reductions in obesity rates, and improvements in physical and metabolic health. Twenty-one studies met the inclusion criteria, covering a range of intervention strategies. Most interventions featured structured PA programmes, often with personalised components and ongoing support. Several high-quality studies demonstrated long-term PA adherence, increased weekly energy expenditure, and improvements in fitness. However, adherence rates varied, with participants meeting recommended PA levels ranging from 4.6–81%. The meta-analysis showed a small to moderate positive effect of PA interventions on outcomes like PA levels and weight loss, with an effect size of 0.37 (CI: 0.25–0.50). The results highlight the need for tailored, culturally sensitive interventions, particularly for vulnerable populations. Long-term PA adherence is stronger in older adults than middle-aged ones, but the sustainability of these effects remains unclear, warranting further research