"Jonathan McCullum was in excellent health at 155 pounds when he left last summer to spend the school year as an exchange student in Egypt. But when he returned home to Maine just four months later, the 5-foot-9 teenager weighed a mere 97 pounds and was so weak that he struggled to carry his baggage or climb a flight of stairs. Doctors said he was at risk of a heart attack. McCullum says he was denied sufficient food while staying with a family of Coptic Christians, who fast for more than 200 days a year, a regimen unmatched by other Christians."