"'Carbs' can mean broccoli or pure sugar." And since this analysis is using published scientific papers, you can be reasonably sure that the investigators did

"'Carbs' can mean broccoli or pure sugar." And since this analysis is using published scientific papers, you can be reasonably sure that the investigators did not make these kinds of completely novice errors in methodology. Certainly not across the board. I have never seen a study of the issue that confuses simple sugars with cellulose. Nearly all studies are based on the glycemic index, and use high- or low-glycemic-index foods as their discriminator. Most scientists are actually pretty good at their jobs. Obvious factors are controlled wherever possible. If you want to make this kind of a critique to a meta-analysis, you're actually making an extraordinary claim, and you must provide extraordinary evidence of improbable, correlated errors in the underlying studies.