Nope. It would require less farming to feed people than to feed animals and people to eat those animals. Energy loss is an order of magnitude. If you ate the plants instead of eating the animals eating the plants it would be more energy efficient.
I don't know anything about growing meat in the lab, but it doesn't sound very appealing and I've lost any desire to eat meat long ago so I don't really care either way. The theoretical potential to grow meat isn't in any way a convincing argument to make eating meat right this minute either non-cruel or energy efficient however.
