Me too, through much of my 20s and 30s. (Not MD . . Pepsi . . but metabolically basically the same thing.) Then I had a family, and needed life insurance, and couldn't get it, because of metabolic syndrome (obesity, high blood pressure, high blood glucose, the whole works). I decided, this past summer, to make what I hope will be permanent lifestyle changes to try to reverse this damage. I'm now mostly soda-free, HFCS-free, still addicted to some other sweets (and other high-glycemic carbs which are almost as bad), but working on it. Trying to exercise more and to eat mostly nutrient-dense rather than calorie-dense foods. I look and feel better already, but BP and other numbers are still bad. I expect to have to lose much of the fat I gained before they improve enough for me to represent a decent risk to a life insurance company, and, by then, I may well be in my mid-50s, so it will still be expensive, but it will be possible. I wish I could go back in time and change this nasty habit, perhaps by educating myself better about what it would ultimately entail, not just for me but much more importantly for the people I love.
You may very well have some manifestations of metabolic syndrome, not all of which are outwardly apparent. If you have access to decent healthcare, get yourself checked out, even if you feel and look otherwise healthy. But be aware that most doctors will want to prescribe drugs, which will treat some of the symptoms but possibly at the expense of causing or exacerbating others. What you really want instead is to eliminate the cause, which most nutritionists believe to be consumption of sugars and high-glycemic carbs, which trigger insulin and leptin surges, resistance to these and other hunger-related hormones over time, and a positive feedback loop eventually leading to high blood pressure, heart and artery disease, diabetes, obesity, and a high risk of death from stroke, heart attack, or renal failure. Most people who have not yet been hospitalized for one or more of these ailments - and even some who have - have been able to reverse them through proper nutrition and exercise.