Dietary needs vary by individual, and unvarying rules cannot regulate everyone's habits because foods wholesome to one may harm another.

Original passage

There is real common sense in dietetic reform. The subject should be studied broadly and deeply, and no one should criticize others because their practice is not, in all things, in harmony with his own. It is impossible to make an unvarying rule to regulate everyone's habits, and no one should think himself a criterion for all. Not all can eat the same things. Foods that are palatable and wholesome to one person may be distasteful, and even harmful, to another. Some cannot use milk, while others thrive on it. Some persons cannot digest peas and beans; others find them wholesome. For some the coarser grain preparations are good food, while others cannot use them.