They Go Gluten-Free (For No Good Reason)
The rationale: "I've heard that some people feel less bloated when they give up gluten."
The mistake: Those who suffer from wheat-related bloat may have Celiac disease, an autoimmune disorder in which wheat damages the small intestine—but it affects less than one percent of Americans (the less-severe gluten insensitivity is also less common than most people realize). The gluten warning is specifically intended for those diagnosed with one of these conditions, but the Nutrition Twins see many people using it like a weight loss plan. These misguided dieters avoid all forms of gluten—including satisfying, heart-healthy whole grains—and, worse, swap food made from wheat flour for food made with processed rice, corn or soy flour. These commercial products can also be high in sugar and sodium, making them more unhealthy than the food they're intended to replace.
Try this: The 2010 Dietary Guidelines for Americans recommends that everyone switch from refined grains to whole grains. Even those diagnosed with a gluten sensitivity can still enjoy naturally gluten-free grains like amaranth, buckwheat, flax, millet, quinoa, and teff.