I love science. I tell my Clients all the time that you can actually do scientific experiments on yourself.
You don’t walk through life in a lab, and, there are many confounding variables.
But, generally speaking, if you do a good job of controlling (making no other changes other than the one you seek to measure), you can identify what foods, workouts, or other lifestyle changes work for you. A self-experiment is not without flaws, but, its results cannot be denied.
Unfortunately much of the health & wellness information that is presented in the media as science is built on bad science. There is a large, complex process of biases, significance, and distillation that any informed learner needs to be aware of. I won’t go down a rabbit hole here, but, one example is that many of the nutrition studies that do not produce significant results never get published at all. And so, while I don’t expect a journal to publish everything, if a group runs an experiment 10 times, but only gets the result they are seeking once, and the fact that nine studies which failed is never even mentioned, then, there is a big gap in the information.
There is a lot of good science out there. Gravity exists. The Earth is round. Gluten & dairy don’t agree with me.
No matter how many times I let an object out of my grip, it falls to the ground. Every time I walk due West 24,901 miles along the equator, I end up back at the same spot that I started. (Just kidding!) And, every time I accidentally eat some wheat or a lot of dairy, I get an upset stomach.
If you can measure it and repeat it, then it works for you. This is not to be overlooked.
There are many good studies on diets that works for large groups of people. But you might not be in that group.
You’ve got to figure out what works for you, and only you can truly affirm that.