Obesity and Natural Products: Mechanisms, Therapeutic Potential, and Future Directions

Obesity represents a major global public health challenge, currently affecting over 890 million adults worldwide and substantially increasing the risk of type 2 diabetes, cardiovascular diseases, and metabolic syndrome. Although several pharmacological agents are available for obesity management, their clinical use is often limited by adverse effects, high costs, and suboptimal long-term efficacy. These limitations have driven growing interest in natural products as complementary or alternative therapeutic options. Bioactive compounds derived from medicinal plants, fruits, and vegetables, such as polyphenols, flavonoids, alkaloids, terpenoids, saponins, and carotenoids, have shown promising anti-obesity effects through multi-targeted mechanisms. This narrative review summarizes current in vitro, preclinical, and clinical evidence on the role of natural products in obesity management, with particular emphasis on their ability to modulate lipid metabolism, inhibit adipogenesis, enhance energy expenditure, regulate appetite-related pathways, influence gut microbiota, and attenuate oxidative stress and inflammation. Compounds including epigallocatechin-3-gallate, curcumin, resveratrol, capsaicin, and berberine have demonstrated notable efficacy in experimental models, with increasing clinical data supporting their therapeutic potential. Nonetheless, challenges related to standardization, bioavailability, quality control, and regulatory approval remain major barriers to clinical translation. Addressing these issues is essential for the rational integration of natural products into evidence-based obesity management strategies.