No. You should give advice that causes good outcomes. You don't need to do anything else. We know that low carb diets have higher all-cause mortality. Because

No. You should give advice that causes good outcomes. You don't need to do anything else. We know that low carb diets have higher all-cause mortality. Because of this, telling people to eat low carb will (probably) cause a bad outcome. If we want a good outcome, we need to work out more specific advice. To be clear, advice doesn't always have to be very specific. This particular advice needs to be improved, because it looks like it would kill more of them than current dietary advice. We can tell it would kill them because the meta-analysis several comments above shows an increase in all cause mortality. This is not the same as telling people where the pharmacy is, because A) we have no studies at all about going to the pharmacy, B) people need to get important medicine from the pharmacy and going to it could plausibly lower mortality, and C) telling someone where to find a building is not lifelong public health advice and the risk for one person crossing one road is miniscule anyway.