[emmelaich]

Of course food shortage was a factor;

> Rice yield per acre had been stagnant since the beginning of the twentieth century;[25] coupled with a rising population, this created pressures that were a leading factor in the famine

https://en.wikipedia.org/wiki/Bengal_famine_of_1943

Add to that transport impact (floods, war), the drop in imports from Burma and other factors.

[_2d30]

FWIW, your quote doesn't support a food shortage being a cause since it says nothing about the relative change of total planted acreage.