Obviously there could be many factors. I want to point out, though, that a caloric deficit is a marginal difference. That means small changes in the base calori

Obviously there could be many factors. I want to point out, though, that a caloric deficit is a marginal difference. That means small changes in the base calorie intake can lead to a many-fold increase in your caloric deficit. As an example, let’s say you go from a healthy adult at 18 years old and 160 lbs, to an obese adult at 40 and 300 pounds. That’s 140 pounds over 22 years. If a pound of weight is gained after 3,500 excess calories, then this person only consumed roughly 60 extra calories a day. If they consumed only 20 excess calories a day, they would be 195. Overweight, but still relatively healthy. It doesn’t take a lot of sugar to add 40 or 60 calories to someone’s diet and leave everything else unchanged.