I would like to THANK YOU ALL for your comments, honestly I did not expect that much comments. I will take time to review them and try to get the best from them.
What's annoyed me a lot is, the CTO had a meeting with most of us and I was there to tell us he is going to ask for pay raise to match the market and he did not mention any relation with work performance however the happy ending was not for all of us.
I do like the way you are looking at the problem, but as high overview it's all down to supermarket to provide this information (if they got it and easy to share).
I was hoping to find kinda open data date for grocery food but still looking for.
Hope get more people interested on the idea so it gives me a push to explore more paths to solve the problem.
Yes having to scan you bill/receipt is the approach I am thinking of but how are providers/supermarkets willing to give this data? or I have to find away to get these information somehow.
As I wrote in another comment, I would like to know how many are interested on this idea to see if the journey is worth to take.
@trtobe: you could ask the supermarkets. Doesn't hurt. Perhaps you would have better luck promoting this idea with grocery stores that have loyalty cards? Loyalty cards I suppose are already used to track specific users and what they purchase. I think working with the supermarkets are better because it results in a more frictionless experience.
I agree spending hour(s) scanning or tapping is not the solution. Be fair we will be lazy to do so.
First I wanted to know if the idea got traction before investing time on it.
I was thinking about image recognition but still we have to spend time to store all the data.
I was more thinking approaching providers/supermarket to add this information on the receipt so you have just to scan it to get all needed information but this doable is worth to ask.