Q: When should I send a second inquiry about my manuscript's status to the journal editorial office?

Six months does seem like a long time for an article to be "Under Review" unless you belong to a field like mathematics or economics where the review times are unusually high. Also, going by the journal's response, there seems to be no clear end date for the peer review. It is likely the journal has had challenges finding the right peer reviewer for the article. You can write to them two to three weeks after your last communication. However, this time, apart from asking for an update, also share your anxiety about the time being taken. If you still don’t receive a positive or definite response, in a later mail, you could consider withdrawing the article from their journal and submitting to another journal.

Related reading:

• How to communicate with the journal editor

It is difficult for us to help you write a concept paper on the topic of your choice. However, we can guide you on how to go about it. As you may already know, a concept paper is a short paper (about two-three pages long) written before undertaking a study outlining key aspects of the study. You should choose a research question based on the following factors: how relevant it is (to the target population), how novel it is, and how it builds on existing research (or suggests directions for future research). To arrive at a research question, you need to do a comprehensive review of the literature on the topic. In your case, you could go through recent literature on fast food consumption (in the country and also internationally, if needed) to explore various aspects and perspectives, such as consumption patterns, links to lifestyle, impact on health, and alternatives. Doing an extensive literature review will not only help you arrive at an appropriate research question, but also help you write the other elements of the concept paper. Here are some resources on how to do a literature search and choose a research question:

• A young researcher's guide to digital tools for literature search and reference management
• How to choose a research question

All the best for your literature review and concept paper!