The first aspect of the invention relates to a phosphoinositide 3-kinase inhibitor for use in the treatment or prevention of a disease or condition associated with the expression of peroxisome proliferator-activated receptor gamma coactivator 1-α (Pgc1α) and/or uncoupling protein 1 (Thermogenin/Ucp1) in brown adipocytes. The disease or condition may be positive energy imbalance-associated, for example, obesity, an obesity-associated disease or condition, steatosis and biological aging (performance aging). Another aspect of the invention provides the use of a phosphoinositide 3-kinase inhibitor for promoting weight loss in an individual.
