While CICO is universally true, it doesn't account for a few other factors. For instance, gut microbiome. Gut flora has a strong affect on cravings. Also mental and emotional health also affect self control and regulation. Food "science" has created craving monstrosities snacks that are as addictive as cigarettes. Personal health issues like PCOS and thyroid dysfunction will affect how many calories are consumed by the body and how those calories are used within the body.

So yes, eat less and lose weight. Sure. Some people can lose weight eating junk. For others it creates a reward cascade in the brain that leads to overeating. Just eat less. For some that's as practical as telling a lifelong smoker to give up the habit. And that's why medical alternatives to self control exist, but aren't successful without addressing the root cause of the obesity.