Practical Advice - problems at work

Thank you for this. I am having problems at the moment! I am Type 1, and started a new job in January this year. I did not know when accepting the job that it was run along the lines of a call centre, in fact I was told on more that one occasion when making the application that this was definitely not the case!
So, I now find myself in a position where strict bra peaks have to be adhered to, in terms of when I am allowed to eat. Unfortunately, this means that I may have my lunch at anytime between 11.30 and 13.30! Although there is a 15 minute break in the morning and again in the afternoon, I am still not allowed to eat something at my desk should I need to. In fact, I was once told off for earring a Rolo when I felt I was going a bit low! This is just one example of direct discrimination that I have had reason to speak to them ion about. What makes matters worse is that the Team Manager is Type 2, but is ignorant enough to think that I can manage in the same way as her, i e. have a round of toast for breakfast and then have nothing apart from an apple for lunch at 1 or 2! And, consequently, she of course is allowed to eat and drink whatever she wants, when she wants!
I didn't manage to get my lunch until 13:40 today (should have been 1pm), but because of sickness and the person coming back late, I had to wait. This is causing big problems in that I have to make up for highs and lows by having sugary snacks in break times, full sugar drinks on my desk in case of emergencies, having to inject, more than I normally would, and having knock on effects, one of which is weight gain!
I have contacted HR three times now asking for their policy on disabled workers. Their latest answer is to send the sickness policy!
Does anyone have any suggestions please?

Are you on a basal/ bolus insulin schedule?

I worked in a call centre briefly. I spoke to my manager before starting and explained I would need to keep glucose and snacks with me at my desk in case my blood sugar was low and I needed to eat. I presented it as something I had to do with my diabetes, almost like part of my medication. I also explained that if my BS was low I wouldn't be able to deal with people on the phone properly. I also explained I'd have to do blood tests.

I never had a problem even though I don't think they really understood. They just accepted I did what I had to.

Could you arrange a meeting with your manager and explain what you need? Your employer should make 'reasonable adjustments'.

Why aren't you allowed food at your desk? Is it for safety or because of taking calls? Perhaps you could tell your manager how you'd deal with that.