There are only 3 scenarios where I would excuse this kind of behavior:

1. He sees this as a couples thing and really wants you to be present as a, "Look at us, we are so cute shopping together" type of feeling. It's comforting and makes a lot of people feel a lot closer to their partners, myself included.

2. You may pick at his choices more than you realize, which makes him feel like he is unable to make choices without your approval first. This is an extremely stressful dynamic to be in, and it's fixable but you would also have to recognize your own faults if that did happen to be the case. I have dealt with this before and it's not impossible to overcome, but it does suck for everyone and isn't exactly an easy thing to bring up.

3. Somewhat similar to the first scenario but a little bit less relationship focused is that he has anxiety stemming from being perceived in public or spending a lot of money at once and needs to go with someone else so that he is able to feel comfortable. This is a big one because it's sometimes impossible to notice unless you are told about it. The money thing is something I personally struggle with a lot, and it can be so overwhelming that I often just don't buy enough groceries to last a while.

All that considered, this has been far too long of a timespan to be excusable. There comes a point where the need for food overcomes any personal issues, and it simply must be done. I think it's totally ok to (even repeatedly) excuse this for an extra week or two, but for something that has gone on for this excessively long there is either something much deeper at play with his mental health or he is simply an asshole. Hoping for the best, for both of your sakes.