Comment by rafram
We already have the FDA (most foods and drugs), the USDA (produce, animal products besides milk), and TTB (alcohol). Each one sets its own safety and labeling standards, which is why, for example, mixed drinks containing alcohol don't have to list allergens(!). Another level of fragmentation would be a disaster IMO. We could split the FDA, but we'd need to merge the food regulator half into one of those other existing agencies.
To be honest, I could see an argument for separating the handling of raw agricultural product from the rest of the food system. The health effects of Oreos vs. making sure our eggs don’t have bird flu are quite different regulatory concerns.