What happens when you evolve later?

Question

If you hit the b button and stop a Pokemon from evolving, will it have lower stats if I evolve it later as opposed to evolving it now? For example:
1: I evolve Foongus into Amoongus at level 39, and level grind until it's level 45.
2: I restrict Foongus's evolution until it gets to level 45, then I evolve it.

Will example 2 have lower overall stats? Or will both have the same stats?

Answer 1

They will both have the same stats once Foongus evolves. Here's what happens:
Foongus has its own max stats since it is the pre-evolution. It will have lower stats than it would as an Amoongus. Once it evolves, it will receive a stat boost because Amoongus has higher base stats than Foongus. So it would automatically have the same stats it would if you evolved it, then leveled it up to LV 45. You would have to take EVs into the equation, though, since those would change its stats in any situation. Click this link if you don't know what EVs are: http://pokemondb.net/ev