Junhao Huang ^1* Xu Yan ² Bing Shen ³ Liwei Xie ⁴ Chia-Hua Kuo ⁵

• ¹ Guangzhou Sport University, Guangzhou, China
• ² Victoria University, Australia, Melbourne, Victoria, Australia
• ³ Macau University of Science and Technology, Taipa, Macao, Macao, SAR China
• ⁴ Guangdong Academy of Sciences, Guangzhou, China
• ⁵ University of Taipei, Taipei, Taiwan

major global health challenge with important clinical implications 1 . As a complex disease characterized by abnormal or excessive fat accumulation, obesity increases the risk of many other diseases and health problems, such as metabolic diseases, cardiovascular diseases, cognitive dysfunction, sleep apnea, cancers, etc. In recent years, efforts have been made in investigating the lifestyle strategies which may prevent or treat obesity. Exercise have been shown to reduce the risk of obesity. However, it is still unclear which specific modality of exercise may have a more significant effect on reducing obesity. More studies are still needed to investigate the optimal exercise mode, intensity, and frequency, as well as explore the underlying mechanisms behind the changes in obesity. Besides exercise, diet is another important factor that may affect obesity. Furthermore, growing evidence has shown that exercise can increase the release of cytokines, such as IL-6, FGF21, and myostatin, from skeletal muscle or other organs into the blood. These cytokines can modulate adipose tissue metabolism 2 . However, there is still much to explore to fully understand the roles of exercise-induced cytokines and the underlying mechanisms involved, especially in relation to the treatment and prevention of obesity.In this research topic, a total of 7 papers were published to cover the above-mentioned aspects among different populations.One cross-sectional study (Zhu et al.) 3 Besides observational studies, one intervention study (Wang et al.) 6 compared the acute effects of three exercise modalities including tabata, high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT) on the energy expenditure and substrate metabolism in male university students with overweight/obesity. This study reported that, during both the exercise and recovery phases, tabata exhibited a significantly higher fat oxidation rate than HIIT and MICT and suggested that tabata can be used as an efficient short-term weight loss exercise program for male college students with overweight/obesity.Besides the original studies, two meta-analyses were also published in this research topic. One meta-analysis (Wang et al.) 7 The last paper in this research topic (Wen et al.) 9 focused on the relationship between an adipokine called Apelin-13 and metabolic diseases and exercise. The review summarized the recent studies on the relationship between Apelin-13 and related metabolic diseases as well as the regulatory effects of exercise on Apelin-13 and concluded that more studies are still needed to investigate the effects of exercise with different types, intensities, and amounts on Apelin-13 in the future.In summary, there are large varieties among the included studies in this research topic. However, most of the studies further support the benefits of physical activity and on reducing the risk of obesity among different populations. Additionally, diet is another important factor that may affect obesity. However, the effects of combined exercise and diet on obesity are still unclear so far. Unfortunately, no related studies were included in this research topic. In addition, there is only one study related to cytokines in this topic. Obviously, further research is needed to explore the relationship between lifestyle interventions and obesity as well as the underlying mechanisms.