I don't fully blame OP, the HN title is simply wrong. The paper does not say that weight loss lowers the risk of diabetes. Which would imply a causal relations

I don't fully blame OP, the HN title is simply wrong. The paper does not say that weight loss lowers the risk of diabetes. Which would imply a causal relationship. The paper says that "lifestyle intervention" lowers the risk of diabetes. This intervention could also explain the weight loss, hence a corollary relationship. That said, there is such a thing as bad science and there is literally decades of it when it comes to nutrition and chronic diseases. And more keeps coming out all the time. I don't blame the OP for being skeptical, but he/she was skeptical of the wrong thing in this case.