I always look at questions like that as me VS a completely healthy person. SO the fact that you have dietary/preparation restrictions whereas a completely healthy person would not...IMHO I'd rate that as moderate to severe probably erring on the side of severe.

When I was helping hubby fill out his disability papers that was what his doc and Pdoc told us, don't look at it as you look at it as you VS a perfectly healthy person. Because hubby had been ill so long we'd made so many "systems" to help him through his day that to us we'd rate things at none or mild and the doc would throw an absolute hissy fit saying that it was severe. That if a healthy person had to go through the processes he did they would think it was a major impairment.

I hope that made sense