[wnorris510]

If you have a known bowl and fill it to a known position every day with the same type of food, then you can probably do better than the average for that specific meal. In our research we've found a majority of calories for most people come from when they're eating out and consuming new dishes where they don't know the ingredients or portion sizes.

In the study we gave people a variety of dishes to make their estimate on, some they were familiar with, some they were not.

The professionals were nutritionists who had trained in portion size estimation and were shown 2D images on a computer screen.

For what it's worth, we've had a lot of people who have claimed to be very accurate at portion size estimation from a long history of using a kitchen scale. We've paid many of them to do a quiz to see if they're above average accuracy and they have almost always ended up around 40% accuracy or worse.

[shawabawa3]

estimating from a photograph is always going to have huge error because you just cannot know e.g. the size of the plate without some external reference

[wnorris510]

Modern phones have LiDAR that give you the near exact volume and dimensions of everything on a plate. That's what we do:

https://www.snapcalorie.com/

We co-authored a paper on this with Google AI and showed it got about 2x the accuracy of a nutritionist because of it.

[maeil]

I'd love to do such a quiz -I might even be willing to pay for the privilege! I'm quite convinced I'm really accurate at calorie estimation without using a scale but would love to be proven wrong. Zero food industry experience here, just from reading hundreds of food labels per year since very young, maybe 8 years old.

Thinking about it again, I'll probably do a lot worse from a picture because I can't have a bite of the food! Just having a spoon makes it so much easier in terms of ratios.