If you ignore the fad diets, it’s not that bad. Science can change on specific points over time but it’s been pretty uncontroversial for many decades that a diet of fresh foods with plenty of fruits and vegetables and a moderate intake of meat and fish, with a minimum of sugar and junk food, is good for you.

It’s just that occasionally something comes along that we really want to be true, like wine is healthy or all-meat is actually good because the cavemen did it. When the finding is something we want to be true, we’ll blow a minor, flawed study all out of proportion and keep talking about it years after it’s debunked.