the western world is somewhat becoming obese, but doesn't suffer from famine at all, 3rd world countries with problems industrialising farming do have increasing problems with famine as population increases.
If we didn't farm as intensively as we did, the western world would also be starving.
We still ship in VAST quantities of food from around the world, which doesn't go to much closer countries that have huge famine problems. We import craploads of fruit from Africa, while Ethiopa suffers, we import rice while places far closer to where it is grown also suffer with famine.
Imagine if money was taken out of the equation a vast portion of our food stops being shipped in and our intensive farming methods didn't work anymore, think what would happen. Same situation that occurs elsewhere in the world would happen here, rich/greedy get more, others suffer.
You're confusing the existance of famine, with the lack of it here.
There also actually is give or take enough food for the world being produced now, but greed as I've said generally prevents it going where its needed. People here and many places eat far more than they should, while many people in Asia and Africa die every day from famine. If the US/UK/EU produced a lot less food, well, we'd likely take a lot more food from other continents but also generally have less food "at home" as well.
I mean, common infections killing people is all but irradicated in the UK and has been for 50 years, but people die from basic infections in other parts of the world. Solving something in one location doesn't solve it for everyone.