The limiting factor to agriculture is the need for nitrate and phosphate. Nitrate fertilizer is made industrially from natural gas. Phosphate is largely mined. An emerging problem is that the world's topsoil is deteriorating at a high rate.

It's not a question of lab grown meats and fats: it's the core staple products of wheat, rice, corn, and soybeans. These supply the wold's calories, either directly or indirectly, and they cannot exist without natural gas and mined phosphate. Lab grown foods will still need feed, likely to come from some combo of soy and corn. It doesn't get us around this problem.

When exactly this could be a problem is a subject of speculation. I think Malthus was probably too pessimistic, and was focused on the wrong parts of the issue. Current pessimistic predictions have us either exhausting our easy phosphate supply, or destroying our topsoils, long before we use all the available natural gas.