An impoverished diet lacking sufficient nourishment produces poverty of the blood and difficult-to-cure conditions like dyspepsia and general debility.

Original passage

Because principle requires us to discard those things that irritate the stomach and impair health, we should remember that an impoverished diet produces poverty of the blood. Cases of disease most difficult to cure result from this cause. The system is not sufficiently nourished, and dyspepsia and general debility are the result. Those who use such a diet are not always compelled by poverty to do so, but they choose it through ignorance or negligence, or to carry out their erroneous ideas of reform.