MY diet is VERY similar that I have been following. With a few exceptions. Here it is, straight from his own diary!
5 egg omelet with 3 ounces cheese and chicken
2 cups of coffee
8 ounces of chicken and diet soda
Milk
Protein Powder
Coffee
16 ounces of fish with 1 Lite Beer.
This was followed for a few weeks prior to the 1980 Olympia.
Offseason diet, yes.
Several friends know Frank and it's common knowledge that you can purchase a training weekend with him and he goes over his contest "diet" and none of the diets he writes to clients is there that much dairy and protein in one sitting (5 eggs and chicken) cheese and milk same day.
Don't know where this was pulled but this was before e would start prep. His protein of choice was fish and he would and still does eat like a bird. Breakfast 3 to 4 eggs and half a grapefruit, etc.