To be sure, the fact that calories, particularly empty calories bereft of nutrients, have never in human history been more easily available or cheaper is certainly part of the equation. So is the fact that most of us have sedentary occupations and struggle to find time and motivation to participate in physical exercise. Still, these factors impact almost everyone, but only some of us become obese. That's why some people like to blame alleged character flaws in obese people. The reality, however is that there really seems to be no particular type of person who becomes obese.
Honestly, however, all we know for sure at this point is that, once we become obese, it's extremely difficult to lose the weight. Our bodies appear to be set up to want to maintain our weight -- whatever weight that may be -- and they do everything they can to thwart our attempts to reduce our size, including manufacturing hormones which make us feel ever more hungry and slowing down the rate at which we burn calories.
When it comes to finding an ultimate cause, obesity remains largely a health mystery. Fortunately, we at least have one working solution in bariatric surgery. We've now proven through countless studies and massive anecdotal data that these procedures not only make it a lot less comfortable to overeat, procedures such as a gastric sleeve surgery render metabolic changes that seem to help patients do what many of them previously thought was next to impossible: losing significant weight and keeping it off in the long run.
So, yes, we're not at all sure what to blame obesity on, but at least we have one effective solution.