This section is from the book "The Hygienic System: Fasting And Sun Bathing", by Herbert M. Shelton. Also available from Amazon: The Hygienic System Vol III Fasting and Sun Bathing.
Certain advocates of flesh eating, particularly one who lectures on the radio and gives away hams as a means of securing an audience, caution vegetarians against fasting. They tell vegetarians that they are the last who should fast. Why? Because fasting is "more likely to cause serious acidosis in vegetarians and others with low protein reserves. Diets high in protein of poor quality may be more harmful than low protein diets which provide the essential amino acids in good proportions."
This objection to fasting by vegetarians is not based on experience and observation, but is purely theoretical. This is one of those instances where "the facts of experience silence the voice of theory." It is not only true that vegetarians stand fasting better than heavy flesh eaters, it is equally true that light meat eaters stand fasting better than heavy consumers of flesh. Every advocate of fasting from Jennings, Graham and Trall to the present is in agreement on this.
Trall said of his observations in conducting his establishment, "containing more than a hundred inmates on the average, about half of whom were either vegetarian in principle, or were restricted to an exclusively vegetable diet by special prescription, that such patients can bear fasting for a time much better than the flesh eaters; and they usually suffer but little, in comparison with those who enjoyed a mixed diet, from the craving sensation of the stomach, on the approach of the dinner or supper hour. To this rule I have never known one exception."