Question about weight of food....

Depends on the listing. If the listing says "grilled chicken breast" then it is the weight after cooking. If it says raw, then it's the weight before cooking.

You should definitely choose the listings that are specific about cooked or raw. I was so confused by chicken was so much more caloric than turkey until I realized I was entering raw weight for cooked chicken (but did the turkey correctly).

A side note, I'm a chemist and we never weigh things while they are hot; it messes with the measurement and the scale. I'm guessing most kitchen scales are not that measurement sensitive, but you might want to be cautious measuring hot cooked food. I try to measure them all raw since I tend to mix things together or forget to measure after I get done cooking.