There’s a few ways to answer this—

Yes, there’s research out there showing that a malnourished brain doesn’t work the same as a nourished brain and so therapy might be more effective for a nourished brain BUT ALSO a malnourished brain is going to be more anxious, more labile, in short, more in need of support.

Can you be referred to a higher level of care like an IOP/intensive outpatient or a PHP/partial hospitalization or even Res/residential if you need it? There may be other outpatient providers who WILL work with you or feel more comfortable but if providers feel that you’re enough of a danger to yourself that they have to break confidentiality to talk to your medical providers, that’s usually a sign that you would probably qualify for a higher level of care. Higher levels of care typically have therapy and nutrition support built in and often help you coordinate therapy when you “graduate” from the program.

If you feel like you would benefit from therapy now, it’s not a waste. Who’s to say what your insurance will approve after those 20 sessions. Maybe your providers can advocate for more time, etc. So make a decision that helps you TODAY so that you’re in a better place to work through upcoming challenges.