Worldwide obesity has risen to record levels generating a major risk factor for metabolic syndrome, diabetes, hypertension, and cardiovascular disease as well as cancer and neurodegenerative diseases. Here we discuss the impact of obesity on lifespan and cardiometabolic disease in mice and humans and how different types of fasting can help prevent and treat them. We argue that specific types of fasting regimens which are associated with low burden, high long-term compliance and safety, can reduce obesity and other disease risk factors, lower morbidity and extend healthspan.