[zahlman]

>people are on average off by 53% and even trained professionals are still off by 40%. Basically if you want to have a higher level of accuracy you need to use a food scale or something that measure the volume of food, people just can't estimate portion sizes visually.

I can typically estimate them accurately without direct measurement, and with feedback that will tend to make errors cancel out over time. My trick is to note package weights, and divide containers into N equal portions. That is: I decide a target portion size first, and then portion it out.

If the task is "measure out an ounce of butter" I realistically won't be 40% off - because I can very accurately divide a rectangular solid in half repeatedly, and the butter comes in a one-pound package. Similarly, I have a pretty good idea how much grilled chicken is on my plate, because I know how much raw chicken I cooked, because I made a whole piece from a pack of N roughly-equal pieces weighing X (values which I noted when I bought it).

[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.