There have been a ton of threads here on Veganism, with die hards for and against, so I expect someone here might offer an opinion.
I have been a strict Vegetarian (almost Vegan) almost a year. I "converted" because I thought it an ethical way to reduce animal suffering.
Since switching, I gained almost 20 pounds.
Conversely, at the same time, my Mom switched to diet very high in meat (modified Keto) and lost 40 pounds.
I suppose I can exercise more to fight off weight gain, but the real issue is my immune system seems weakened. Healing times are much slower. For example, if I get a skin issue, such as an abrasion, instead of healing in a few days, it lingers for a month or so.
Reading on this, this relates to deficiencies in key proteins - and seems a common side effect of Vegan diet.
I suppose it might be possible to improve/avoid this with careful meal planning, but I feel I shouldn't need a Food Science degree to make dinner.
I haven't gone "off the wagon" just yet, but am seriously considering it. A weak immune systems in a global pandemic seems like asking for trouble.