Not only am I the father of an Iraq combat veteran but a Baptist elder as well...
I read the original article and the point of it was that eating meat was energy intensive rather than suggesting bicycling was inefficient. I recommend the articles on nutrition and physiology from "High Tech Cycling" 2nd Ed. by Edmond Burke. Cyclists are 20 to 25% efficient in converting carbohydrates to mechanical energy. See "Diet for a Small Planet" by Francis Lappe for information on getting a complete protein supply from combinations of non meat sources. Add soybeans and wheat, peas and rice, or beans and corn to get protein and carbohydrates together. These 'cheap fuels' are ideal for cycling whether you enjoy meat and ice cream as well. Venison and turkey make for a tasty meat loaf if you want to spare the environment from corn fed beef.