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People are bad at reporting what they eat. That's a problem for dietary research

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Re: People are bad at reporting what they eat. That's a problem for dietary research

#241

Post by dailykoder »

marinmania wrote: post #175
wnorris510 wrote: post #130

I've done research in this space for many years at Google AI and now at SnapCalorie. The thing I find interesting is how confident people are in their ability to estimate portion size visually, and in truth how wrong they all are. We published in CVPR (top peer reviewed academic conference for computer vision) and people are on average off by 53% and even trained professionals are still off by 40%. Basically if you w…

I highly recommend people get a food scale/measuring cups and weighing everything single thing they eat (even small things like nuts and cooking oil) for at least two weeks. After that I think you have a much better appreciation for how many calories your regular meals and snacks have.

I counted calories and put everything on a scale, for about 2 or 3 months in 2022 (iirc). And you are 100% right. I had absolutely no idea how much calories some food has. There were a lot of things, but I think cashews were my biggest eye opener (probably obvious to a lot of people). I easily achieved my goal of -10kg and saved A LOT of money, because I always had food prepared. And since I was going for a calorie deficit, I easily could afford a few sweets on the weekend.

Then I obviously got lazy. And while I sometimes still think I can estimate how much I am eating, I am probably wrong, because my bathroom scale says something different. My key takeaway is that it takes quite a bit of effort, but once you got into a routine, it's not hard.

Edit: Also, while I might have tried to ditch "wasted calories", I didn't put too much effort in eating healthy. One step at a time.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#242

Post by ellisv »

vladvasiliu wrote: post #166
taeric wrote: post #153

Earlier quoted context omitted.

This goes a long way to further convince me that it is portion sizes in the US. Having traveled, it is quite absurd to see the difference in standard order sizes. Even for zero calorie things like water and unsweetened teas/coffees. You just get smaller cups. I'm not even sure you can get a US large in Japan for most drinks?

Probably depends on where you go. I don't know about "the US", but as a "European" I thought serving sizes were comparable to what I get in restaurants at home. Drinks were an exception, since basically all restaurants had unlimited soda for next to nothing. This was actually great, since I was riding a motorbike in the desert in July. For reference, I live in France and visited LA and random towns in the western sta…

I'm a big fan of European serving sizes compared to U.S. for food – but when it comes to beverages, particularly water, I can't believe how much they charge you for how little they give. I understand everything comes in bottles with VAT but even asking for tap water I found they'd only bring a very small glass.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#243

Post by michchinn »

wnorris510 wrote: post #130

I've done research in this space for many years at Google AI and now at SnapCalorie. The thing I find interesting is how confident people are in their ability to estimate portion size visually, and in truth how wrong they all are. We published in CVPR (top peer reviewed academic conference for computer vision) and people are on average off by 53% and even trained professionals are still off by 40%. Basically if you w…

From the paper (https://openaccess.thecvf.com/content/CVPR2021/papers/Thames...):

> We asked them to estimate the mass of each ingredient present on the plate and subsequently converted these values into nutrition estimates using the same USDA [9] values we used to create our dataset

I get that there's a linear relationship between the mass of a food and its calories, but I'd expect that nutritionists would be better at estimating the calories in a plate of food than the mass of a food item. Most people aren't doing the math in their heads, they're using a frame of reference that recognizes calories. Did you have this in mind? Is there any research on this?

Re: People are bad at reporting what they eat. That's a problem for dietary research

#244

Post by ellisv »

pavel_lishin wrote: post #179
tejohnso wrote: post #177

Earlier quoted context omitted.

> you need to use a food scale or something that measure the volume of food Isn't that obvious? Basic high school science projects would have students using measuring devices. Are you saying that it's common for nutritional studies to tell people to eyeball their portions and that is then used as actual data? I see from the article "Nutritional epidemiology studies typically ask people to keep a food diary or complet…

I would wager that just paying attention to, and thinking about what someone eats has a decent impact on their health - so it feels like it's working, and like your estimates are accurate. After all - once you started doing it, you started losing weight/building muscle/achieving whatever result.

Yes, the mere act of monitoring (including self-monitoring) leads to behavioral change.

This alone can be sufficient for some people.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#245

Post by rconti »

TypingOutBugs wrote: post #6

I try calorie count with My Fitness Pal and holy shit it’s a lot of effort. Eat out and you’re screwed (estimated at best). When you include sauces and oils etc it’s really hard to be accurate in the best of times, and it’s just a pain to keep on top of. Best option is to avoid any so you don’t have to count. I imagine almost everyone will add bad data in a study at some point with the best of intentions.

I've used it on and off for 7 or 8 years and it's the only thing that can consistently help me lose weight. Even just the mindfulness of knowing how much you're eating and how much you're exercising are helpful in the process. You don't have to be that accurate on exact calorie counts for this to work.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#246

Post by jacobr1 »

taeric wrote: post #214
lotsoweiners wrote: post #191

Earlier quoted context omitted.

New York deli sandwiches are certainly not representative of what you get everywhere in the US. They are famously large.

They may be famously large, but I don't think they are abnormally large for most of the US nowadays? I certainly didn't think they were particularly big when I visited.

Katz serves roughly 3/4 lbs of meat. That is particularly big. You can get triple hamburgers which would be similar is size - but most people are ordering singles or doubles. And you can find other kinds of large sandwiches around the country ... but it is not the most common of sizes.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#247

Post by ttoinou »

landtuna wrote: post #234
everdrive wrote: post #81

A lot of people seem to have a purely emotional relationship with resources which logic doesn't seem to be able to penetrate. Food and finances seem similar here. For years I tried to get my wife to stick to a grocery budget. That is, we have $n per week for all groceries. She'd blow badly over the limit every time. "But we needed [food]" or "These were toiletries, so they don't _count_ as groceries." Ultimately we n…

I never understood why calories in == calories out was relevant when we can't know how many unprocessed calories are remaining undigested. Here's what the bots had to say: https://www.perplexity.ai/search/weight-loss-gurus-often-say... (FYI - I stay thin by limiting calories, so I don't disagree that fewer calories causes weight loss)

This theory is not scientific (food is not energy, the body is not a machine, measurements are not precise etc.) so there is nothing rationale you can say that will convince people who believe in it to switch to something else

Re: People are bad at reporting what they eat. That's a problem for dietary research

#248

Post by jeltz »

ellisv wrote: post #242
vladvasiliu wrote: post #166

Earlier quoted context omitted.

Probably depends on where you go. I don't know about "the US", but as a "European" I thought serving sizes were comparable to what I get in restaurants at home. Drinks were an exception, since basically all restaurants had unlimited soda for next to nothing. This was actually great, since I was riding a motorbike in the desert in July. For reference, I live in France and visited LA and random towns in the western sta…

I'm a big fan of European serving sizes compared to U.S. for food – but when it comes to beverages, particularly water, I can't believe how much they charge you for how little they give. I understand everything comes in bottles with VAT but even asking for tap water I found they'd only bring a very small glass.

In some European countries water is free. I am from Sweden where all places have free tap water and fancy places often have free sparkling water.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#249

Post by vidarh »

dnpls wrote: post #131
beezlebroxxxxxx wrote: post #70

Earlier quoted context omitted.

Counting works for people because it quantifies their food intake. For many people, that's an effective way to overcome a learned idea that portions should be huge, or that feeling hungry has to be addressed immediately, or that feeling "full" has to be constant. It's not perfect, and I don't recommend it to people with an ED history; however, after about a month or 2 of doing it, it can really change how you look at…

This is it. There will always going to be impossibly unpredictable errors even if you measure everything perfectly. The point of measuring is to be * as accurate as possible *, not 100% error-free. It helps to better estimate portion sizes, calorie / macro amounts. This is enough precision to control weight gain / loss correctly. A lot of people also get their maintenance calories estimation wrong, so it doesn't matt…

A lot of people mess up more by doing a maintenance calorie estimation wrong and relying on it rather than counting calories coupled with weighing themselves and adjusting calorie intake up/down depending on whether they lose/add weight... If you use a feedback loop, then indeed it doesn't matter if your calorie estimate is anywhere near correct anyway, as long as you're reasonably consistent and the errors aren't too badly skewed toward the wrong foods.

Re: People are bad at reporting what they eat. That's a problem for dietary research

#250

Post by jacobr1 »

ellisv wrote: post #244
pavel_lishin wrote: post #179

Earlier quoted context omitted.

I would wager that just paying attention to, and thinking about what someone eats has a decent impact on their health - so it feels like it's working, and like your estimates are accurate. After all - once you started doing it, you started losing weight/building muscle/achieving whatever result.

Yes, the mere act of monitoring (including self-monitoring) leads to behavioral change. This alone can be sufficient for some people.

One factor is just the sheer volume of snacks and treats - outside of the portion size of any particular meal. If your were not self-aware of constant eating that can have a big impact - at least it did for a few friends of mine.
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