Does obesity affect your life expectancy?

Yes. Obesity can increase your risk for health problems, such as diabetes and high blood pressure, which can shorten your life expectancy.
Yes. Obesity affects many bodily systems known to shorten life span. It contributes to sleep apnea, diabetes, stroke, hbp, cancer, psychological issues, stigma, life satisfaction and stress - all known to affect life span. Remember - you have a lifetime to work on it - don't look to "diets" look towards expanding your life via dietary change (permanent and not temporarily) make choices for life.