You can be healthy eating very little or no meat. Many monks can attest to that fact.
Sure, and some Saints lived from the Holy Eucharist alone, but that's not true for "normal" people who don't benefit from special graces.
Related: before the Universal Flood, we didn't need to eat meat (and weren't allowed to).
But the Flood changed everything to be much worse than before...
Now we can't stay healthy without eating meat/fish. We should be aware of that fact!
(Anyone telling you otherwise has been brainwashed...)