But if you want to know what we believe to be true about which foods are healthy, there's probably no better starting point than Harvard's Healthy Eating Plate.
- https://www.hsph.harvard.edu/nutritionsource/healthy-eating-...
Avoiding processed foods and refined sugar is good. Avoiding dairy is good. But there's no reason in general to avoid cereal grains, legumes or potatoes unless you're sensitive/allergic.
And higher-quality meat is an improvement over the status quo but a vegetarian diet is likely to be healthier.
But all that is me talking, not my wife. I suspect she would say similar things but honestly we don't spend a lot of time discussing the random fad diet book du-jour.
Many people would consider a diet like this difficult, but if you approach it correctly (I end up cooking a lot of szechuan cuisine), it's quite easy—and delicious!