Just as one size does not fit all when it comes to almost any pursuit in life, the same is true for dieting – in fact, nutritionists have observed that what may work for weight loss for one person doesn’t always work for another. And now, a study in the journal Cell begins to figure out why this is the case. It turns out that people metabolize food very differently depending on their individual makeup – and the makeup of their gut microbes. What may lead to a slow, steady rise in blood sugar for one person may lead to a bizarre spike in blood sugar for another.