My experience in PAF is worth sharing. My visits as junior officer, I observed that airmen messes provide tasty and balanced food. The lunch and dinner menu had always two dishes daal/vegetable and some meat (white or red) with bread or rice and a seasonal fruit or some sweet. As visiting officers we share their food and after that we have to log condition of mess, its dinning hall and quality of food. Yes you are right about field exercises when forward operating base are activated, then most of the time engineering officers eat the lunch and dinner with JCOs, NCOs and other technicians.
I am sure same traditions must be followed in Army and Navy as Jawans and officers are more closely integrated with each other due to regular war exercises and rigorous joint training.