My BMI is under 20 but I have more body fat than I’d like (bit of a belly) despite running and lifting. I have tried for years to cut out or cut down the fried processed foods and chocolate, but cannot seem to do so without entering a binge/restrict cycle. It’s compulsive. It makes me feel like crap and I don’t even love the taste that much any more. I can’t explain it any way other than addiction.
I’m lucky my hunger hormones (and possibly love of exercise) keep me a normal size, otherwise with my dietary composition I’m sure I’d be obese too.