According to the experts, obesity plays a crucial role in the body's battle against age-related disorders at the cellular level. Obesity, they write, accelerates immune system aging by targeting distinct immune cells, and losing weight afterwards will not necessarily reverse the process. Obesity has been shown to increase your risk of developing diseases such as diabetes, heart disease, and cancer later in life. It also decreases life expectancy by an average of six months. The main cause of death for people who are obese is cardiovascular disease. Studies have shown that adding mild exercise to an obese person's daily routine can significantly improve blood pressure and other markers related to heart health. There are several theories on how obesity affects aging. One theory is called the "metabolic theory." This theory states that obesity causes multiple metabolic problems within the body, resulting in increased inflammation and decreased immunity over time. The "insulin theory" suggests that insulin resistance leads to higher levels of insulin in the body, which in turn causes increased inflammation and accelerated aging. The "prolactin theory" explains that hyperprolactinemia, or high levels of prolactin (a hormone produced by the pituitary gland) in the blood, results from obesity. Experts believe that this hormone may play a role in aging by causing oxidative stress and DNA damage.