Well, you can find studies that support whatever diet approach you want, that much is true. There is definitely a lot of bad science out there, and a lot of it has to do with who funds the study and what their financial motives are for a particular outcome.
What we can say with some certainty, though, is that throughout about 99%+ of our evolutionary history, humans have eaten whole/real foods such as meat (and the fat that meat contains), fish, roots/tubers, various plants, berries and other fruits, nuts, seeds, some honey,etc.. About 10,000 - 15,000 years ago, humans started consuming grains, for the first time (10,000 years is a very small blip in our evolutionary history). It is only within the last 70-100 years or so, that we have had this explosion of highly-processed, manufactured foods that now comprise (by some estimates) around 50% of the typical Western diet. Along with that increase in our consumption of highly-processed foods came an increase in all of the serious chronic diseases that now plague us........diabetes, heart disease, cancer, etc..
So, it's pretty clear to me that most people could improve their diet by just going back to eating mostly whole/real foods, whenever possible. Anything that comes in a box or bag with a long list of ingredients on the side is not real food. I realize this is not easy for most people to do, because most of the grocery store is full of highly-processed food that many of us have eaten (and even enjoyed) for many years. But if you want to improve your health, it is something to at least strive for.
If you think about it that way, you really don't have to worry about whether you are eating low-carb, low-fat, or anything else. As long as you don't get too extreme (and decide to eat only fruit, for example), you can't really go wrong if you are consuming mostly whole/real foods. The saturated fat in meat, for example, is something humans have consumed throughout history, so I don't worry about saturated fat being bad for health. Now, consuming something like canola oil (which is an industrial product unlike anything humans have ever consumed until the last several decades) is something you should worry about.
That's the way I look at it, anyway. YMMV.