There's nothing in soylent that isn't "generally recognised as safe" (GRAS). Some people just have intolerances for some plants. Some common plant products are

There's nothing in soylent that isn't "generally recognised as safe" (GRAS). Some people just have intolerances for some plants. Some common plant products are actually quite dangerous. For instance, grapefruit can interfere with the body breaking down Xanax and Valium. But there's no call for the FDA to stop grapefruit farming.