weighing food to determine serving size

Most food is labeled to be weighed raw.

4 oz of raw chicken cooks down to approximately 3 oz of cooked chicken.

I usually find that it is most accurate to weigh everything (pasta, veggies, meat, rice, etc...) raw! However, it also depends how you are recording it.

If you are using the nutrition facts off of the package, weight it raw.
If you are choosing chicken as an already-listed item, them be sure to read it (they often say roasted, boiled, grilled, etc...)

Weight 1 single piece of chicken raw, then weight it after it's been cooked - big difference...

I'd say after. Especially with pasta, rice, or other foods like vegetables that can absorb water, I would weight after (when it weighs more) to be more conservative with the calories. That is, unless the database tells you that it's X grams uncooked. But I'd play it safe and measure afterwards. With chicken, though, it shouldn't matter, especially if you're baking it or something. That wouldn't change the mass anyway!

I go by whatever the food database, it should tell you if the food is raw or cooked. Otherwise, I always weigh raw, once cooked it will be lighter!

Raw, uncooked.

It depends.....when making hamburgers I weigh them as I am making the patty (so raw) because it also helps me to determine how big to make them.

But for chicken or steak, I weigh them cooked because it is easier. I know they should be weighed raw I believe, but I don't want to worry about getting raw chicken on more surfaces, and then trying to remember which one is mine once it's cooked. I figure the difference is slight, and I don't want to become THAT obsessive about my calories. I think it's important to be accurate, but being too particular is bad I think. For everything that I overestimate, I probably underestimate other stuff.

Besides, how would anyone eat leftovers if you always have to weigh it before hand? Chicken breasts often vary in size, so even if you weighed them raw, how would you keep track of which one weighs what to eat later?

Most products are labeled with their information as they are packaged. Some will actually have two sections one for as packaged and one for prepared. I always measure my meat (I can't help but giggle here) when it is raw.

I'd also like to point out that you should look carefully at the labels. I find a lot of stuff will have two measurements. For example the turkey sausage we like says a serving size is 1 link. HOWEVER, it has grams in parentheses. If you weigh each link in the package they all weigh different grams and almost always they are more than the serving size. So just be aware of this. I know this was an eye opener when we realized it and made a HUGE difference in our weight loss once we corrected it!

Always, always raw with meats. I worked in a specialty food store that had a kitchen and all weights and measurements are done raw.

This is because when you cook something there is no consistency to how much it will weigh when it's cooked. If I give 4oz of raw chicken breast to two different people and let them cook it, person A's cooked chicken might weigh 3.5 oz while person B's weighs 3.25 oz. but both of the cooked amounts have 120 calories in it.

This happens for various reasons, the main one being amount of time cooked. The longer something is cooked the more moisture it loses (hence why overlooked meat is dry). So person B's chicken has .25 oz less water in it now than person A's, and that's all that's different.

It's why when you see ads on TV or listings on menus for "quarter-pound" burgers or a 12 oz steak, there's typically an asterisk with fine print at the bottom that says "pre-cooked weight"

Thanks for asking the question. I just started weighing my food and was looking up what other people have written about the same topic and came by yours.