Anyone who has participated in calorie-tracking for an extended period of time can tell you that the visual appearance of food can be highly misleading to the number of calories in it.
I'm all for making it easier for people to lose weight but this app may honestly have the reverse effect. If the app estimates calories too low (and therefore the individual eats more), many people will get frustrated with the lack of progress and give up. If the app estimates too high, the individual will lose weight, but diet fatigue and other negative side effects of being at a >500 calorie deficit may make the diet too difficult to maintain.
Had a friend who came to me with the same idea. In challenge of the idea I sent a picture of some chopped cucumbers and tomatoes, and an other picture with the same chopped vegetables drizzled with a copious amount of olive oil. I asked if they can tell which one is which. The difference was hundreds of calories and you could not tell which one is which (least of all how much oil there is on the one with the oil.)
That of course feels like a "weird" edge case, but it illustrates the general problem that butter/oil/sugars can pack a lot of calories and have no or almost no visual signature.
My reasoning for evaluating the relevancy of this app:
1. If the food being scanned has a nutrition label, I don't need this app.
2. If there's no nutrition label, the app can't possibly extrapolate the nutritional information. It can't estimate portion size or the ingredients in the recipe.
3. If the app can't extrapolate nutritional information, I don't need this app.
Many people will analyze this from a tech perspective. I urge you not to. This isn't about whether the technology is good or bad. The real reason they succeeded is their mastery of marketing, particularly TikTok and influencer marketing. Understanding distribution is far more important than knowing how to build something, and this is truer now than ever before. I know it stings but its the truth.
>But he looked around. “We were surrounded by people that were in their late 20s or 30s all day. And I realized that if I didn’t go to college, this is what life would be like.”
Lol, I can relate. I started working in an office when I was 16, now 24, and regretting wasting my youth grinding when I could have been having fun in a period of your life you only get to experience once.
Don't grow up too fast kids. Make stupid decisions and ride out your youth as long as you can afford to.
I understand the scepticism here. For sure this app isn’t 90% accurate in any traditional sense.
One note, as someone who also built a calorie tracking app with ai as well as lost a good amount of weight with it: accuracy for calorie tracking doesn’t matter. You can honestly just detect if it’s a meal and return 600 cals. For most people the simple fact that they become aware of what they eat and think about their food in an ongoing basis will lead them to loose Weight.
Sticking to it is the hard part.
I'll bite - I'm an early adopter, and paying user, I paid for the year, but won't renew. For what it's worth, the app UI is dead simple and it makes it easier to track macros. I'll adjust the inputs to what I know I'm eating, and I rarely depend on the "AI camera" I usually just use the UPC barcode scanner. I'm mainly focused on protein intake and making sure I hit those goals. It does a decent job with simple foods, which is healthier for me to eat. I'll break each ingredient down, combine them into meals, then save them. Rinse and repeat for tracking. It's better than a spreadsheet, and I get to see the photos of what I'm eating.
That being said, I'm not going to renew next year. But there is something to this product that is not the "AI" but the simplicity vs. MyFitnessPal which has a ton of features I don't really need.
The critiques are good, but for me, the simplicity of the app is the most attractive part for me.
The app sucks, there’s no reason to use it when myfitnesspal is just leagues better. You can poison it and it will just follow the instructions as well.
The obvious problem with this is how can it tell how large your meal is or how much butter you put in? I can see it working for fast/junk food, though.
When I learnt machine learning one of the things was continually training the model. Like your spam filter. You show it what is spam and eventually it learns. Is this stuff continually trained on the user's BMI? That's the only way to tell if a diet is working. Or is it just making absolute claims based on universal training data?
I'm working on an app in this area [1], and I've spent a lot of time exploring how to responsibly use AI for food tracking.
My conclusion is that while AI is excellent for augmenting your tracking experience, it's not yet reliable enough to be the sole tracking method. Consistency is key to successful food tracking, and AI can certainly help users avoid the common issue of missing a meal and losing momentum. However, inaccuracies, like consistently being off by 100-200 calories per day, can significantly impact results, especially for those on lower-calorie diets (like 1,200-1,500 calories/day, which is common for many women due to their physical size).
With FitBee I landed on communicating to the user that these are estimates and you probably shouldn't use it as your primary method of tracking calories.
A friend of mine build a similar app last year (https://joineat.app) and it didn't go anywhere (even though it is objectively the nicer app). So there's a lot of luck involved here as well (or maybe he was too early).
Been keeping a food diary for several months now. I did have to spend a bit of time at the beginning working out the calorie content of the food I eat. But after that it's mostly just copy + paste - turned out I was far more of a creature of habit than I thought.
If you want to derive any benefit from doing this you should really be trying to get your numbers correct from the start. I wouldn't leave that to a LLM.
I am not sure I could achieve the distribution success of these two. That's worth celebrating.
If I could, I am not sure that I would. This app seems actively harmful. I don't think it can actually do what it claims to do, and that's going to cause real people problems.
It's unfortunate that that disqualifies me from making that kind of money. It's unfortunate that they are allowed to do so.
> The concept is simple: Take a picture of the food you are about to consume, and let the app log calories and macros for you.
> The result is an app that the creators say is 90% accurate, which appears to be good enough for many dieters.
It absolutely cannot be "90% accurate". But I'm sure it seems "90% plausible" to its millions of users.
Incredible that a product like this can exist. Do people just will the fiction into reality?
Incredibly, these are the types of app ideas you'd hear from non-tech "entrepreneurs" in 2012 looking for a co-founder. The problem being, the engineers knew it was impossible. You could fake it I guess by asking Google to search for "similar photos" and getting a plausible calorie count half the time. But the users wouldn't believe it.
We're now at the phase where any impossible idea can be fully marketable by slapping "AI" in the name. ChatGPT feels so magical that we now believe unicorns really do exist.
Seems contradictory that there's a market for this since it requires the same individual to simultaneously be concerned about precisely measuring calories yet willing to pay for a method of doing so that's (probably) wildly inaccurate.
Teemagers not knowing about the limitations of the technology they don't understand. Please don't give them a platform and send them back to school, otherwise we're doomed. This app will harm people.
I thought about doing this years ago, but without AI, the only way was to have people do the analysis. I thought this was bad karma, as I would end up paying people in Bangladesh to look at the stuff that Americans eat.
The comments from HNers in this case are interesting.
Usually if a teenage hacker builds something, the HNers would respond with enthusiasm, but then, this is a guy who builds *something* and *actually* makes a good business out of it, at the same time maintains his high school life, and all we have is skepticism and discouragement.
Photo calorie app Cal AI was built by two teenagers
(techcrunch.com)68 points by PaulHoule 3 April 2025 | 190 comments
Comments
I'm all for making it easier for people to lose weight but this app may honestly have the reverse effect. If the app estimates calories too low (and therefore the individual eats more), many people will get frustrated with the lack of progress and give up. If the app estimates too high, the individual will lose weight, but diet fatigue and other negative side effects of being at a >500 calorie deficit may make the diet too difficult to maintain.
That of course feels like a "weird" edge case, but it illustrates the general problem that butter/oil/sugars can pack a lot of calories and have no or almost no visual signature.
1. If the food being scanned has a nutrition label, I don't need this app.
2. If there's no nutrition label, the app can't possibly extrapolate the nutritional information. It can't estimate portion size or the ingredients in the recipe.
3. If the app can't extrapolate nutritional information, I don't need this app.
4. I don't need this app.
“You can have a full self driving car with just a few cameras”
In a way both things are very much similar and the real accuracy is more of a fiction than reality.
Lol, I can relate. I started working in an office when I was 16, now 24, and regretting wasting my youth grinding when I could have been having fun in a period of your life you only get to experience once.
Don't grow up too fast kids. Make stupid decisions and ride out your youth as long as you can afford to.
One note, as someone who also built a calorie tracking app with ai as well as lost a good amount of weight with it: accuracy for calorie tracking doesn’t matter. You can honestly just detect if it’s a meal and return 600 cals. For most people the simple fact that they become aware of what they eat and think about their food in an ongoing basis will lead them to loose Weight. Sticking to it is the hard part.
Take a picture of everything you eat and correlate it with symptoms. Have AI figure out what may be a trigger.
(I have a super rare food disease that took years to figure out and made my life unbearable).
That being said, I'm not going to renew next year. But there is something to this product that is not the "AI" but the simplicity vs. MyFitnessPal which has a ton of features I don't really need.
The critiques are good, but for me, the simplicity of the app is the most attractive part for me.
When I learnt machine learning one of the things was continually training the model. Like your spam filter. You show it what is spam and eventually it learns. Is this stuff continually trained on the user's BMI? That's the only way to tell if a diet is working. Or is it just making absolute claims based on universal training data?
https://x.com/zach_yadegari/status/1906859987105636667
https://x.com/zach_yadegari/status/1906888487292559531
My conclusion is that while AI is excellent for augmenting your tracking experience, it's not yet reliable enough to be the sole tracking method. Consistency is key to successful food tracking, and AI can certainly help users avoid the common issue of missing a meal and losing momentum. However, inaccuracies, like consistently being off by 100-200 calories per day, can significantly impact results, especially for those on lower-calorie diets (like 1,200-1,500 calories/day, which is common for many women due to their physical size).
With FitBee I landed on communicating to the user that these are estimates and you probably shouldn't use it as your primary method of tracking calories.
[1] https://apps.apple.com/us/app/fitbee-calorie-macro-counter/i...
If you want to derive any benefit from doing this you should really be trying to get your numbers correct from the start. I wouldn't leave that to a LLM.
If I could, I am not sure that I would. This app seems actively harmful. I don't think it can actually do what it claims to do, and that's going to cause real people problems.
It's unfortunate that that disqualifies me from making that kind of money. It's unfortunate that they are allowed to do so.
> The result is an app that the creators say is 90% accurate, which appears to be good enough for many dieters.
It absolutely cannot be "90% accurate". But I'm sure it seems "90% plausible" to its millions of users.
Incredible that a product like this can exist. Do people just will the fiction into reality?
Incredibly, these are the types of app ideas you'd hear from non-tech "entrepreneurs" in 2012 looking for a co-founder. The problem being, the engineers knew it was impossible. You could fake it I guess by asking Google to search for "similar photos" and getting a plausible calorie count half the time. But the users wouldn't believe it.
We're now at the phase where any impossible idea can be fully marketable by slapping "AI" in the name. ChatGPT feels so magical that we now believe unicorns really do exist.
Are you eating a 10% calorie deficit or a 10% calorie surplus? Cal AI can't tell you.
Not possible to know accurately enough from a picture. Potentially ever.
Usually if a teenage hacker builds something, the HNers would respond with enthusiasm, but then, this is a guy who builds *something* and *actually* makes a good business out of it, at the same time maintains his high school life, and all we have is skepticism and discouragement.