a nutritionist and does not advise doing either - for health reasons. Our bodies evolved eating meat and plants. To take away one source of nutrition that our bodies evolved eating requires very disciplined diets to replace the loss. If you have to give up meat at least don’t go vegan unless you are prepared for a very strict regimen.
We cut back on meat to cut back on fat and cut back on processed meat because of the nitrites. But we did not eliminate it from our diet. We still eat a good bit of cheese, but limit the serving sizes due to fat. And we still eat eggs, but not frequently. We drink milk daily plus take calcium supplements. The secret is eat in moderation.
If you notice, the reports on what is healthy changes so frequently and are so contradictory, what they tell you today is bad, tomorrow or next week will be good, and vice-versa.