Both the fields you have mentioned are experience dependent. As a fresher to get a job as a Dietician can be really tough but if you go for physiotherapy then you can work under some senior and with gaining experience you can move out to your own clinic. Also in some hospitals, there are requirements of physiotherapist in the department of orthopaedics and as a result you can work as an junior resident there also to gain experience. So I would suggest than BPT can be more easier to get established as a career but for being a dietician you need to go for higher studies and you have to gain experience in order to get some promising jobs.

To know more about Dietician visit the link below:

https://www.careers360.com/careers/dietitian

To know more about Physiotherapist visit the link below:

https://www.careers360.com/careers/physiotherapist

I hope this answer helps. All the very best for your future endeavors!