To the best of my understanding the cause of obesity is linked to huperinsulinemia and to put it in simple term, it is largely caused by the huge injestion of carb. All carb is converted to glucose and in turn acts on the pancreas to produce more insulin, slowly loading the body with more insulin than needed. From there all the symtoms connected to heart desease become gradually worse as time goes on. To me, and from what I read, the only way to reverse the process is to reduce the carbs along the guidelines of PP Lifeplan thus reducing hyperinsulinemia. While maintaining a primary protein diet and reduced carb the body fat seems to melt away. It appears that's when the hormone glucagone is at work doing the fat burning job. It seem to work for me.

But there are some who are able to eat tons of carbs without putting on weight.
Even for them, carbs are harmful in other ways.