Something that is confusing here with comparing obesity to addictions is that for some obese people, food actually is an addiction (compulsive overeating), whereas for others it is not. Kind of like how someone can be skinny and not eat much food, but they are not the same as someone who has anorexia. You don't have to be a compulsive overeater to get fat, nor do you have to be anorexic to be skinny. If you do have an eating disorder, then it is much tougher to lose or gain weight.
So I don't know if it is fair to compare alcoholism to obesity. Maybe it is more fair to compare it to compulsive overeating disorder.