From reading around, although I didn't find a definitive source worth sharing here, it seems like across several famines in the 1970s, somewhere in the low tens

From reading around, although I didn't find a definitive source worth sharing here, it seems like across several famines in the 1970s, somewhere in the low tens of millions died, while another several tens of millions came close to starvation. So the prediction was off by an order of magnitude.