Title pretty much sums it up. But, here's what I'm thinking, and why I'm asking:

8 years ago I lost 70+ pounds eating ketogenic and doing a 5-day split, so I have experience with splits and I quite enjoy doing something new each day. That being said, after regaining 90 of that 70, I'm finally back into it with full force and 42 re-lost. I want to get back into a routine, but my body is nowhere near where it was when I was hitting the racks.

Should I follow the conventional wisdom on weight training and start with a 3x full body workout until I build my strength back up a bit? Or, is it alright to go ahead and start on a 3-day split? Eventually I'd like to get back to a 5-day split.