I get the impression that much of the official advice of the past was actively harmful; the official advice has flip-flopped on many things over the past decades; things which were touted as healthy were later shown to be unhealthy, and vice versa. So presumably some of the current official advice is also actively harmful, and some of it is merely useless. But I don’t know which.
This is not, in itself, a reason to stop trusting official advice on nutrition. On the science hierarchy of how certain we are of our understanding, nutrition science is very low and physics is very high. So we can treat all nutrition science recommendations as “we believe this slightly more than we believe the opposite”. So it will take a little bit of counter evidence for the field to update its point of view to the opposite. But once that has happened, it will take more counter evidence to flip back. The flip flops will get rarer as evidence accumulates, and at every point in time it could still be that official recommendations are the best that can be made given the data that we currently have. I’m not saying this is the case, but it is consistent with the data of flip flops.
Unfortunately, the official advice lags our current understanding (by decades, maybe). I think that’s a much bigger problem than the perceived flip flopping.
This is not, in itself, a reason to stop trusting official advice on nutrition. On the science hierarchy of how certain we are of our understanding, nutrition science is very low and physics is very high. So we can treat all nutrition science recommendations as “we believe this slightly more than we believe the opposite”. So it will take a little bit of counter evidence for the field to update its point of view to the opposite. But once that has happened, it will take more counter evidence to flip back. The flip flops will get rarer as evidence accumulates, and at every point in time it could still be that official recommendations are the best that can be made given the data that we currently have. I’m not saying this is the case, but it is consistent with the data of flip flops.
Unfortunately, the official advice lags our current understanding (by decades, maybe). I think that’s a much bigger problem than the perceived flip flopping.
I don’t have any advice for nutrition, but examine.com is pretty decent for information about supplements and vitamins, and the NIH guide on supplements is even better: https://ods.od.nih.gov/factsheets/list-all/