I remember when I started med school, periodically I'd learn something that was directly in conflict with some "common knowledge" that I had taken as dogma. A key part of my training, then, was learning about critically-reading the literature, understanding the ins and outs of various research approaches and results, and paying close attention to "evidence based" medicine. Medicine is an interesting field, because sometimes there is no answer, and yet decisions still need to be made and treatment plans developed. Medicine taught me to use the available evidence, but not to become paralyzed by a lack of information, and to always consider the risks/benefits.

My PhD training, was similar in some ways but very different in other ways. A key similarity was critical reading of the literature, and approaching all published work (in the "real" scientific literature) with a healthy dose of skepticism, and then forcing a paper to "prove" its conclusions to me. One area where PhD training is different from MD training is that the PhD side of things refuses to simply believe something because it seems to make sense (generally, no life or death decisions need to be made acutely on the PhD side of my brain). Thus, I tend to be more of a skeptic when I approach any source of information.

All of this training has really helped me filter out the noise that you mentioned. I basically take all news, fitness or diet information that's on websites and blogs, as mostly false. If there's something that's really important to me, then I'll dig out the primary literature to see just how strong the evidence is. Most diet and exercise scientific literature is not highly-rigorous, and so leaves a lot of room for improvement. Even the dogmatic statements that are out there ("you need to drink 6-8 glasses of water a day for good heath") are not well-founded. So, I tend to ignore most of what's out there in the popular literature.

I note that it doesn't help that a "big and famous" nutrition researcher, Brian Wansink, resigned after findings of scientific misconduct by his institution and some retractions of his work from the primary literature! Of course, I assume/hope that this is a mostly-isolated instance, though.

I fact check "research" in the media, how many participants, way of reporting, and conclusion methodology. After digesting that I'll make my decision on facts, and my own knowledge. Might not work for everyone, but seems to work for ME.
As to the "what to eat/what not to eat" I rely on my Dr.'s practice dietician, but still check against what works for me. Anyone want my share of kale?

I pretty much tuned out the chatter right off the bat. When I first started WW I was extremely limited as to any physical exercise till I could get some weight off. When I began to drop I discovered that I was losing as much weight as others that were sweating and working so hard with exercise to lose weight. Of course it was all about getting in your cardio that was the most important thing about exercise that I realized at that point.

I actually today don't pay hardly any attention to the ads and the greatest, latest, new machine ect;. So I really don't have a good source at this point. Since my age and health challenges have come about I'm more or less taking advice from 1. My Nutritionist and 2. Going to the rehab center except that they were slow to open after covid-19 lol.