Thanks Copepod, Northerner and Vince 13 for your comments and links. I'm going to look at the DESMOND link right now.
Fortunately I don't have a sweet tooth and I'm determined to alter my diet for the better. Having rarely read the nutritional info on the packets, I'm becoming an anorak. It's amazing how much sugar is in stuff, something that the majority of you know.
It's the simple, possibly somewhat embarrassing-to-ask because-I-should know-the-answer questions like,
"Will a couple of apples a day cause problems? and
"Having just boosted my Metformin in the last 24 hrs, I do feel a little heady/queasy today - is that due the medication?
that take a bit more searching for the answers.
Thank you all, again, for your kindness and time to answer not just mine, but all the other members posts.
*p.s. I've been trying to think why I'm still feeling "heady" and am wondering if my eating regime today has made things worse. I was told to regularise my meal times and amounts - no problem there. This morning an out of routine job saw me leave home at 0515 and return to eat breakfast at 1000ish instead of 0800. No lunch at midday due to not feeling hungry and am now awaiting my tea. Tonight I don't have tea at the regular time as I'm at a meeting where supper is provided, at 2045.
Would this contribute to the swimming head? I suspect I already know the answer.