Obesity is the leading, modifiable risk factor for cardiometabolic morbidity and mortality worldwide. It is beyond doubt that accumulated and dysfunctional adipose tissue is an active player that connects obesity to its major complications. To address this rising public health issue, diverse pharmacological, surgical, and lifestyle interventions have been developed and practiced. We now know that adipose tissue responds to each type of intervention by weight loss-dependent and -independent alterations, which underlie at least part of the metabolic benefits of weight loss, e.g. improvements in components of the metabolic syndrome. On the other hand, certain adipose tissue adaptations are important factors that compromise the maintenance of a reduced body weight and drive fat regain. A critical component of this phenomenon are dynamic changes in both the presence and activity of adipose tissue-resident immune cells. In contrast to other tissues, such as the liver, visceral adipose tissue curiously retains some degree of inflammation and insulin resistance even after successful weight loss. As of today, most aspects of the “what”, “where”, and “how” of adaptive responses that occur in each adipose tissue depot and their clinical implications remain to be elucidated. Hence, the objective of the present collection is to cover both innovative and established methods used in studying in vitro, ex vivo, and in vivo responses of preadipocytes and adipose tissues to diet, exercise, cold exposure, nutraceuticals, pharmaceuticals, and bariatric surgery. Among others, assessment methods of adjustments in myeloid cells, angiogenic activity, adipocyte browning, and shifts in the adipose tissue transcriptome and secretome fall within the scope of this collection. Gaining a deeper understanding in this important field not only gives insight into identifying more effective therapeutic targets, but also contributes to conceptualizing novel measures to prevent weight regain in obese patients.