Treat it like the addiction it is, and you said it yourself.
Here's a copypasta from another comment I made.
Society and the easy access to indulging high caloric and straight up unhealthy food. You don't see a lot (if any) fat people in certain parts of the world where access to cheap, unhealthy, highly caloric food is not as readily available as it is in the US. The literal problem around here is "I have too much access to food, and I'm unable to stop myself from eating it".
Some people get addicted to cocaine, others to meth, heroine, others to alcohol, and others, to food (Sugar has been found to be MORE addicting than cocaine BTW). So it is an addiction problem, but because it is tabboo to tell someone they should eat that much, it becomes a hard problem to address.
They appeal to emotion, i.e. "I will be hungry, do you know how hard is to go hungry?", yeah, thats your body craving its addiction, you know how hard is to quit alcohol cold turkey? It literally can kill you, so its almost the same with food.
Someone else commented that some people lose a lot of weight, and then they gain it again 5 years down the road. Thats because the adiction won, at that point you gotta treat your food habits like an addiction. At least with alcohol and drugs, you can literally avoid it and not go near it, and still live fine. You cannot live without food so it makes the tempation of overindulging even higher.