It is a problem you find it to be mind-boggling and problematic. For instance, there is a myth that eating many eggs can result in high cholesterol. This is a problem to be tested. If so, how did the previous research say about it? Any external factors can link to high C? Maybe you also read the papers, test it out rigorously, monitor your bodies, and so on. This is what a research problem look like. After that, you need to explain why it formulates as a problem. Maybe you can say the previous research did not consider the individual differences in consuming eggs... So you try to understand this gap from your own perspectives, which you think it is worth to explore.
You generally have to find a "gap" in the literature that you wish to explore; something that has not been investigated or something that has been investigated and you want to confute / challenge. So, basically, first you need to know what has been discussed (and found) by other scholars. Then you can formulate your research question(s) on the topic you wish to explore.