Q1: I did not, although I partially credit that to taking fairly gradual steps toward carnivore (I was meat + fruit only for ~6mos. before going full carnivore). My buddy I did it alongside with definitely felt a drop in energy as his body transitioned out of carb energy to fat adaptation; i.e. the "keto flu", however it only lasted about 1-2 weeks.

Q2: YES. This has been a huge benefit. During the last 3 months of carnivore, I've worked out far less than ever before in my life (I explain why here), yet have become more cut than ever before. This has been wild, as before, if I didn't work out fairly regularly, I'd always have a little bit of puff on my stomach. Now I have that defined line down the middle without needing to work for it; it's just there by default, which rocks. For the rest of my body, the muscle on my arms/legs definitely stays there much better than it did when I ate plants. It's quite wild how eating the proper human diet just keeps you rock solid naturally.

Q3: I hate awkward social situations, especially when I'm the cause of them. This happens a lot on this diet; I have to be the "difficult one" anytime I'm out eating with friends, giving the poor waiter a laundry list of things to not do (no seasoning, no seed oils on the grill, no sides, etc. etc.). It's not easy. But if you truly care about being your absolute best, it's worth it! This is a big reason why so many Bitcoiners are able to maintain carnivore; we have a reputation for proudly rejecting clown world and all its rituals, which you definitely have to do in order to remain dedicated to this way of eating. Also diarrhea for a while in the beginning lmao, that's a classic, and not the most fun, but quite common as your gut adapts.

Also I have no down sides yet. Way cheaper, way easier, way less time consumed, my guts feel way better, way less stiff in the morning, aches and pains are gone and I feel way less bogged down.

I have only been doing it for a few weeks and have had way more energy and after 2 days, my lingering lower back injury that was 6 months old was basically gone.