> I don't know why I haven't seen more studies where extremely obese individuals just stop eating.

It's probably not common because you'd be trying to study the one thing they have the most trouble doing. To understand what I mean, you have to understand that asking an extremely obese person to stop eating is like asking an Alcoholic to stop drinking. All of them know that's what they have to do but that's literally their problem, they can't stop drinking and extremely obese people can't stop eating. More importantly, the drinking and eating in these diseases is not the problem per se, they're typically symptoms of less obvious root problems.

In the case of food, these people get a dopamine rush each time they eat. It makes them feel good. But then they feel bad because they're getting fatter (for various physiological, social and psychological reasons), which then makes them want to eat more because that at least makes them feel good (temporarily). It's pretty easy to spot the mental illness and similarity to drug addiction in this feedback loop.

I know this is hard to swallow for people who find it easy not to be alcoholics or overeaters but here's a journal article that studied the connection:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166230/

They say there is strong evidence that food addiction is similar to opiate and other psychoactive drug addictions. It also calls out alcohol and carbohydrate binges as stimulants for the brain's production and utilization of dopamine. The carbohydrates part is interesting since of course, that's literally what pig farmers use to fatten up pigs. So of course, if eating those makes you feel good and eating too many of them makes you fat then problem really starts to make sense.

I used to be obese. When I moved to a new city and found a new doctor, I asked him if there was anyone I could talk to so I could get more help. He told me it's simple, I just need to eat less and exercise more. I've been called a lot of lousy names in my life, but what he said was the most insulting thing I had ever heard... that it was simple.

You don't tell an alcoholic it's simple not to be an alcoholic, "Just stop drinking!" or to a drug addict, "Just stop taking drugs!". It's simple for you, but it's not simple for them. That's what makes them an alcoholic and not you.

I had lost 50lbs about 10 years earlier, so I knew the technical requirements to lose weight. My problem was not with dietary knowledge or exercise. But, as many doctors do, they give you advice/pills/creams/etc to improve the symptoms rather than trying to understand the root problem. I don't blame the doctor though, he didn't understand my problem.

In these cases, it has to be treated as an addiction and that's how I approached it. Once I realized my problem was one of addiction, I started to make some progress. I started to realize I would zombie walk to the kitchen like an addict in a daze, looking for a fix. I was thinking about something else completely but my body was on autopilot looking for food. I had a problem with food itself. Definitely carbs (especially sugar). I read a lot about eating disorders to better understand the problem and hoped to find a solution to the problem and not just the symptom.

I wish I found out about the link between carbs/dopamine a lot sooner. I discovered it accidentally when I found out about the Keto diet around 2013. When I cut out almost all carbs, I quickly discovered my brain fog went away, I felt happy most of the time, I wanted to exercise, I had more energy, and finally... I didn't want to eat all the time.

So, that was the basic solution for me, but even then it wasn't easy or simple. I did a lot of research and it took many false starts to finally make good progress.

I'm sorry for the wall of text, and for hijacking your comment, but I hope this helps some people understand why it's not simple to do (or study) and I hope it helps some people who have an eating disorder find their path or get professional help (if they'll listen).