Gluten is the sticky protein found in wheat, barley, and rye.
Already present in most breads, cakes, pasta, pizza, and
beer, gluten is also added to a wide variety of other products
for its gooey, mouth-pleasing abilities—but mouths may be
the only thing that gluten is making happy. Recent research
suggests that gluten may present a unique inflammatory
challenge, impairing insulin sensitivity and predisposing one
to weight gain irrespective of the carbohydrates with which
it is bundled. Case in point: mice that were fed diets with
added gluten gained more weight than mice fed the same
diets without gluten.^24 These mice had reduced metabolic
activity and increased markers of inflammation compared to
control mice consuming the exact same number of calories,
carbs, and fat—the only difference was they were
consuming gluten. The fact that this was a mouse study may
tempt you to balk, but don’t. “Overall, the mammalian
digestive tract is strongly conserved, with major differences
between species being likely driven by diet. Given their
shared omnivorous nature, humans and mice thus share
strong similarities,” wrote researchers addressing the
question of mouse model utility in studies on the gut in the
journal Disease Models & Mechanisms.^25 This adds to the
growing body of evidence suggesting that gluten’s impact
extends far beyond the digestive tract—a fact that I will
explore in depth in chapter 7.