There is a caveat. Most science, even when high calibre and delivering clear results, doesnt reliably predict wwhat individuals should do. It only speaks to an average across the population. Individuals have unique responses, which can vary by degree and also by direction. The gold standard is always careful experimentation on a case by case basis. This phenomena is more apparent in diet science where dissecting causation and elaborating mechanism is particularly difficult. Many studies are narrow in scope, with short duration, and applied to limited demographic types... limiting generalisability. Larger, longer studies in more natural contexts produce results that often conflict, presumably because of factors we don't fully understand.
So my two cents would be to remember that results of studies are not always true for individuals, annoying as that is. If you're serious about change you'll need to experiment.