This works in the case of {steak,fish,chicken} because those options are pretty close to identical in their overall role in a diet. But there are also nutrition strategies for which cycling is worse than any of the options. A straightforward example of this is keto. Conventional wisdom is that these are highly nonlinear; a diet which is low-carb but not low-carb enough is substantially worse than either a low-carb or a full-carb diet. And there’s a switchover period with some adverse effects, so cycling between keto-days and non-keto-days would be bad.
This works in the case of {steak,fish,chicken} because those options are pretty close to identical in their overall role in a diet. But there are also nutrition strategies for which cycling is worse than any of the options. A straightforward example of this is keto. Conventional wisdom is that these are highly nonlinear; a diet which is low-carb but not low-carb enough is substantially worse than either a low-carb or a full-carb diet. And there’s a switchover period with some adverse effects, so cycling between keto-days and non-keto-days would be bad.