Diet, Exercise for submissive

Frist you need to talk with your Dominant about your goals and what your punishment will be.
This is the perfect opportunity for a Dominant to step up and inject himself into His submissive life to help her be the best version of herself.
This holds two parts in a D/s relationship responsibility and accountability.
The Dominant is responsible for monitoring your diet and exercises.
The sub is fully accountable for delivering results.
This is how it works.

Startup up phase: simple reporting it's simple rule you report when you exercise. And you will report what you ate.
There is no consequences for food choices or lack of experience during this phase this is just get you in habit of reporting.

Tighting the lease phase: This begins the enforcing the decision you may ask some sort of verification.
Examples
Like a photo of your meal
Record of your exercise
Note: Most phones have apps exercise tracker, pedometer ect

Accountability phase: There needs to be consequences for failure. Yes we are talking about punishment but the Dominant needs to treat lightly here not so much with exercise but with food there could be issues there so no shaming.