You've heard the story before: when you eat carbohydrate-rich foods that digest quickly, it sends your blood sugar and insulin levels soaring, then your blood sugar level comes crashing back down and you feel hungry and cranky. You reach for more carbohydrate, perpetuating the cycle of crashes, overeating, and fat gain.
It sounds pretty reasonable– in fact, so reasonable that it's commonly stated as fact in popular media and in casual conversation. This idea is so deeply ingrained in the popular psyche that people often say "I have low blood sugar" instead of "I'm hungry" or "I'm tired". But this hypothesis has a big problem: despite extensive research, it hasn't been clearly supported. I've written about this issue before (1).
A new study offers a straightforward test of the hypothesis, and once again finds it lacking.