Two years ago, I was at 300 pounds. Today, I float between 250 - 260. That number is slowly and steadiliy going down.
I can easily sit down and eat two frozen pizzas at a time, but I choose not to do so. I could eat 2 or 3 thick burgers from Hardees. I choose to avoid Hardees 99% of the time. When I don't avoid Hardees, I buy 1 burger.
As the original OP stated, the extra bowls of ice cream and entire pies probably have a lot to do with the obesity of the people he witnessed at Golden Corral. This is not the case for everyone, but I would say several. If people would stop GORGING themselves until they can't eat anymore, they wouldn't get into the shape they are in now.
Strictly my opinion here (I'm NOT a medical professional): if obesity is a medical condition, so is starvation. Luckily, BOTH can be handled with proper diet. If you are suffering from starvation, eat something, preferably something healthy. If you are obese, eat healthier and in slowly decreasing amounts. Medicine and pills are NOT the answer.