There is one very good reason to avoid wheat: if you have celiac disease, also known as gluten-sensitive enteropathy or nontropical sprue. Celiac disease has become more common in the past 50 years for largely unknown reasons.
The U.S. Dietary Guidelines advise that at least half your daily grain intake be whole grains. That’s easier said than done, in part because it can be hard to identify truly “whole grain” foods. This rule can help you quickly calculate.