This is, of course, blindingly obvious.
But it's not really an ideal long-term solution is it? In fact it reminds me a little of a joke by Tommy Cooper: "I went to my doctor the other day and said, It hurts when I do this" [briskly raises left arm above his head] "He said, Well don't do it then". Trouble is I really like food, so the wider variety and range of quantities I can eat the better - not necessarily all the time, but certainly every now and then. But these occasional guilty pleasures are not at all enjoyable if they always result in disastrous BG levels.
Part of the frustration stems from the fact that my insulin:carb ratio which in theory should allow me to eat pretty much whatever I like, seems to be less than predictable in certain circumstances. Almost everyone, I suspect, who adjusts doses this way will be familiar with the experience of counting carbs in an unusual meal carefully, taking the 'right' dose, only for BG chaos to follow. This can be particularly frustrating where I know I can achieve pretty good results for notoriously difficult meals (pizza or fish and chips for example) if I eat the 'usual' amount and take the 'usual' split dose, even if the actual carbs involved are not measured or counted very accurately at all.
A few very interesting comments came out of my forum post. I'm always suspicious of 'rules of thumb', but someone remembered a suggestion from John Walsh's excellent 'Using Insulin':
Take your weight in pounds and halve it, then use that figure as grams of carbs - this gives a good indication of the meal size above which your insulin:carb ratio may well break down. It might not work for everyone, but it's pretty much bang-on for me. Someone else suggested that above a certain point they found they needed to add approximately a third to the calculated dose for it to work well.Last night, we had a mixture of 'heat it and eat it' ready meals from the supermarket, and I ventured a pudding too. Overall mine ran to just over 90g carbs with a fairly high fat content. Not horrendously high carb load, but enough in recent weeks to cause problems. I decided to experiment with the new 'adding a third' approach and split the dose as if I were eating fish and chips. The results were excellent - 4.8mmol/L (86) before the meal, 5.0mmol/L (90) at one hour and 6.2mmol/L (112) at just over two hours. By hour three I was still pottering along at 6.1mmol/L (110) with a mix of the split doses still active. By suppertime I'd dropped back to 4.7mmol/L (85). That's a little low to go to bed on, so I had a small snack to prevent a dip overnight. FBG this morning was 5.0mmol/L (90). Cracking!
It's a bit early to believe that this will solve all my problems for unusual
meals in the future, but it's certainly a system I'll try again.