[wnorris510]

Yeah, dividing out a known portion size is a good hack that will probably help with accuracy. In our research most people's calories and error came from eating out where they didn't have these hints, but this is a good trick if you mostly cook for yourself!

[ericjmorey]

I started eating half of whatever was served as an individual portion whenever I was at a restaurant and not home cooking. It's the thing that tipped the scales for me when having difficulty losing weight.

[zahlman]

Historically I would rely on the restaurant's printed nutrition info. But I don't really eat out often enough for this to matter.

[tombert]

It can still be useful just to get rough estimates of what you're making at home, especially for portions and products that are roughly comparable.

If I make an egg, cheese, and sausage sandwich in the morning, and forget to weigh out or count how much of something I used, it can still be useful for back-of-napkin estimates if I Google the McDonalds Sausage McMuffin with Egg.

Obviously it's not going to be exactly equivalent, but I usually assume my homemade thing is 20% more than the restaurant to compensate.

It's of course better if you just weigh everything out first, you can get much more accurate measurements and calorie estimates then, but this can work in a pinch.