A product that I think is actually vey underrated is Aqueon betta food. Many people seem to look down upon it but based on the research I have done about ingredients in foods, it is what I would recommend people get if they can't get NLS...
One reason is that the first ingredients is whole fish meal. This is considered a quality ingredient and is listed as it's dry weight. Non meal items, such as "whole salmon" for example, is listed as it's wet weight. The wet weight is the weight of the item before it's cooked, so the final product that you buy and use has the item as it's dry weight. The dry weight is 20% of the wet weight. So when an ingredient is listed as a meal, you know it's position on tue list is accurate.
Another reason is that it lists "whole wheat flour" which indicates less product splitting. Product splitting is when a company will list components of an ingredient as seperate ingredients. This allows a company to put less desireable ingredients further down the list.
One more thing that I would like to add is that the food includes "whole dried krill" within the first five ingredients. Krill is very nutritious.
So, in conclusion, NLS is still my favorite fish food, but Aqueon betta food is a solid second, and I would feed it to my betta with a clear conscience.