I am just happening to have a vegetarian day to day. Not planned, but the result of a sudden need to reorganise my menu plan to allow for a visit from DD, over tomorrow lunch
That is what being an omnivore means you chose from the wide range of foods available to you in order to have a mixed diet.
Some years ago the food writer came up with the mantra^Eat well, not too much, mostly plants^ and its corollary If its made from a plant eat it, if it is made in a plant don't
I use these two statements as the guiding lights to my relaxed eatn style.