I hate to say this, but there is sometimes sugar in Chick Tik Masala sauce, and each restaurant will be slightly different .... if in doubt about stuff, and I'd known I was having an Indian at the weekend, yesterday in Tescos I'd have looked at their 'take away' curries cos if memory serves me right, the nutrition info is on the packaging so I'd have checked it and scribbled it in my diary, to refer to on Saturday. You then have to sort of decide whether it's about the same amount or not and adjust it up or down accordingly.
Warburtons packets tell you what's in a slice - there's a column for '100g' and then to the right, it says per slice. The medium sliced is 17.7g per slice. So the thick sliced may be slightly more than 20g, dunno cos I never have thick LOL
Heinz soup cans ditto - a small can of tomato - 300g - is 30.1g so 400g would be 40g. Think Tesco own brand is about the same. So I'd have called it 100g. (except personally I couldn't have eaten all that!)
I couldn't do that with soup by eyeballing, but I know it says that on the labelling and things I eat frequently I get to remember - so if I had a plate of cream of tomato out somewhere, I could give a good guess.
And apart from under-estimating to be on the safe side, the other thing is when eating out - don't ever do your jab till YOUR food is on the table, because if there is a delay and you've already had your jab ........ (I'm sure we've all been there done that and had to drink emergency 'full fat' Coke that we didn't want !!!)
Enjoy! - ooh and if drinking alcohol with/before or after the curry, underestimate a bit more too .....