in regards to losing/gaining weight.
If your lifting weights, eating every 3-4 hours is acceptable for gaining maintaining/weight.
If your not, all it will do is put you in a leptin resistance state, which you don’t want. Your just end up gaining fat & having to retrain your body to normal eating patterns.
As it quite stressful having these symptoms, your cortisol is likely to be higher than normal, which means you will be burning more muscle than if you had a balanced homeostasis. Less muscle means slower metabolism.
If you have adrenal burnout, eating frequently is suggested, but make you sure you get your macro nutrition right to suit what your going though.
I know its frustrating, but personally I wouldn’t aim to gain weight for the sake of it, the body will be responding differently. So eat when your hungry, not because you feel you have too.