It would be convenient if customers could filter grocery items by nutrition information. For example, someone on a keto diet could filter items in grocery by grams of carbohydrates, fat, and protein, or someone on a cleanse could filter by grams of sugar or added sugar. It could be similar to the price filter in which you choose a preset range or enter in a custom range. I'm always looking for new healthy options. Filtering this way could increase search results beyond the way the items are marketed. People are always trying different diets, and the nutrition data is already required by law. It would just be a matter of writing the code which could be easily adapted from the price filters, and of course, entering all the data which would be quite a task. I think customers would really like it and it could give Amazon a boost in the grocery shopping market (not that Amazon needs any boosts!).
(I just had the idea while shopping on Amazon Fresh, so I Googled how to submit a suggestion... I hope this is an acceptable forum...)