Hi, my nutrition niche is about true facts about nutrition as opposed to the popular beliefs. Still looking for a WS name to change it to as mine is not indicative of what I am doing. As I began to blog a few yrs ago, I found my style developed itself and all the old info I had collected over many years in my head came out very direct and shocking to many, I suppose, but I like to call it inspiring. My goal is to wake people up. So you think about what really excites you about this field, what you have researched, and you will find a niche! Maybe you already have.

Hi - I also have an interest in nutrition, having studied it in school (but not in any nutritional niches at the moment). I believe that it might be a good idea to focus on a particular element of nutrition.

Perhaps sports rehydration with sufficient fluids and electrolytes (and post sport meals/supplements).

The elderly also take numerous meal supplements due to their decreased appetite and ability to digest large quantities of food: so meal replacements and/or supplements for the elderly could be another niche.

Furthermore, there are many specialized nutritional recommendations/focuses or "programs" for people with specific health related issues: such as "nutrition for diabetics" or "nutrition for IBS" or "Nutrition for people living with HIV", "nutrition for vegetarians" (since they must ensure adequate protein, iron, vitamins etc that many other people ingest with meat).

The possibilities are there, you just need to pick something that you like :) Hope this helps!