alt Hacker NewsThere is actually an elegant _mathematical_ solution to this problem using sensor fusion and a differential equation model of the science: if you weigh your food almost all of the time at home, and only make portion and ingredient guesses when infrequently eating out, we can actually estimate your personal rate of underestimation and correct for it.
Our startup (BODYSIM.com) has also been doing research on this a long time. As founders, we all have >16 months of daily food logging mostly by kitchen scale weights, aligned to daily BIA-scale weigh-ins, fitness tracker calories, bi-weekly blood tests, monthly DEXAs, 3D scans, etc etc. We also have a science-based structural model of macronutrient balance and muscle hypertrophy. Given all that, we can VERY confidently estimate your TDEE (total daily energy expenditure) and its components, and predict how your fat and muscle mass will change on a daily basis. This is real math/science so you can also run it in reverse. This ("simultaneity constraint") provides enough constraints we can estimate users' individual underestimating/over-indulgence when eating out. In fact, it's better to just NOT log those days AT ALL and we can fill them in. I think this solution isn't more widely used b/c you need all this other "quantified self" type data at the same time.
Replies
How reliable do you find the calories-burned data from fitness trackers to be? Are there any brands that have higher accuracy than others? Are there any hardware features like pulse monitoring that improve the accuracy?
I find that the raw step count varies up to 66% between my phone and my wrist-worn tracker and I can't close that gap just by making sure my phone is never left behind.
This is really interesting, and I'll probably sign up for your app (I'm training for rock climbing). I've used a kitchen scale for a few weeks at home and got pretty good at estimating portion size during that time. Biggest takeaway was that even if you aren't "over-indulging" when you eat out, the portion sizes (especially in the US, less so in Europe) are just insane. 2-3x portions. Ordering half-orders or starters and letting the food settle before eating/ordering more helped quite a bit.