This paper presents three cases involving young Orthodox Jewish males, each of whom lost 15-25 pounds over a course of time ranging between a few months and up to 2 years, as the result of decreased food intake because of misinterpretation of a religious concept learned in their Judaic studies. Although each had a body mass index between 15.8 and 16.1, they did not display the body image concerns necessary for the diagnosis of anorexia nervosa. The discussion covers the distinction between anorexia nervosa and the newly described diagnosis in these young men, i.e., weight loss as a result of religious zeal, along with a brief history of fasting for religious reasons as described in previous centuries.