Exercise improves the metabolic alterations associated with obesity (such as insulin resistance and/or inflammation) independently of weight loss. That is to say, exercise by itself can improve these pathologies even without caloric deficit or weight loss in the subject. However, the loss of visceral fat (fat located internally in the abdomen, surrounding the organs and tissues found there) seems to be a mediator without which substantial improvements in these alterations would not occur, i.e., losing visceral fat is key to the improvement of these metabolic and inflammatory alterations associated with excess fat, regardless of whether or not there are changes in total adiposity.
Exercise decreases visceral fat even without producing relevant weight loss, since the adipocytes (adipose tissue cells) predominant in visceral adipose tissue appear to have a greater number of β3 receptors (exerts lipolytic effects by favoring lipolysis of triglycerides through the action of SLH) releasing stored fatty acids. In addition, the adipocytes of visceral adipose tissue show a decrease in α2 receptors, which has the opposite effect (inhibiting lipolysis).
Thus, the decrease in visceral fat exerted by exercise is greater than that produced by diet (although both are inseparably necessary) as the greater number of β3 receptors facilitates catecholamine-mediated lipolysis (mediated by exercise), which translates into a lower probability of alterations such as an inflammatory state, insulin resistance, etc.
And specifying a little more, strength training seems to be one of the best tools to effectively reduce visceral fat deposits, although so does resistance exercise (especially high intensity), being the concurrence between the two surely the best option. Yes, when we talk about health and fitness improvement, without a doubt strength + cardio always wins.