calories in a tuna fish sandwich?

how many calories and carbs are in a tuna sandwich?

OR, you might use 2 slices of 'lite' bread - 80 calories
1 tbsp of FF mayo - 15 calories

Determined's comes to 470. Mine comes to 245. Again, there are too many variables.

And I like mine w/ a slice of cheese and a sandwhich pickle - add another 70 cals...

And, if you make your tuna w/ mayo, celery, onion and relish? That can add a few more cals too.

This is a question you should get in the habit of figuring out for yourself.
Years of calorie counting has given me the ability to do a "rough est" of calories, so here's my best guess...
tuna - 150
2 slices bread - 220 mayo 1Tbs - 100 total - 470 bread's what, 15g carbs per slice?

Oh, yeah.... that's right... if I add 1/2 a sprig of celery, that means I totally negated the whole calorie value of the whole sandwich .. right. So, adding celery means I can eat all the tuna and bread
I want.

are there any means of measuring how many calories there are in a food. I am under an impression that they somehow 'burn' the food and see how much heat is released. Is it possible to do something like that at home.