Dehydration
Having too much protein can cause your body to flush out water, leaving you dehydrated. Most of the time you can just drink more water to counteract that, but a lot of the time people don’t even realise they’re more thirsty than usual, because a lot of the time we’re not drinking enough water either way.
Unexplained Exhaustion
While protein is a great fuel for our body and is legitimately what our muscles are made of, it’s also not the easiest thing to digest. When you eat too much of it, your digestive system has to work longer and harder to digest it and that can make you feel exhausted, for no apparent reason.