Obesity is an ongoing global epidemic and has adverse consequences for cardiovascular health. Obesity is often associated with hypertension, which is, itself, a common condition and an important cause of morbidity and mortality worldwide. Although animal models of obesity have provided extensive data on the links between obesity and hypertension, a greater understanding of the pathways linking obesity and hypertension in humans is likely to assist translation of animal data, and may, itself, identify important treatment strategies. Ultimately, this could have a substantial impact on human health, both at an individual and population level. The current review will focus specifically on studies of experimental weight gain and weight loss in humans and the following key areas, which are strongly related to blood pressure: cardiovascular function, autonomic nervous system function, metabolic function and the impact of cardiorespiratory fitness.