At the same time, we still have quite limited knowledge on what exactly makes ultraprocessed food so harmful. Is it the additives (and which additives exactly), the process (and which process exactly)? Ultraprocessed food is currently treated with a broad stroke, whereas the harm may well come from a very small fraction of additives and/or processes. All of this is very difficult to disentangle because our previous science indicated that the processes/additives now in use were safe.