The Daniel fast is a religious spin on cleansing diets, and omits meat, dairy, sweets and bread. The idea is to eat the way the biblical Daniel did when after he was held captive in Babylon, and Christians who fast often follow this plan to attempt to grow closer to God.

The Daniel fast includes plant-based foods such as fruits, vegetables, whole grains and beans, and is sometimes called a more restrictive vegan diet. Soy does fall into the bean category; however, the diet does not include any beverages except water, according to Susan Gregory, author of "The Daniel Fast Cookbook." Therefore, drinking soy milk is not allowed. Plant-based milks and juices are allowed in food recipes, however, so feel free to pour soy milk on your cereal.