[andrewvc]

One of the biggest gaps is that people don't understand that food labels are allowed by the FDA to be off by up to 20% in terms of the number of actual calories!

In the real world you need to calibrate your behavior with the results. Are you gaining weight? You'll need to eat less if you want to lose any. You can do all the math with nutrition labels and macros you want but that's all theoretical.

See this study below for the 20% figure, as well as their experimental results on real food items (some even exceeded this threshold though most were within it). https://pmc.ncbi.nlm.nih.gov/articles/PMC3605747/?st_source=...

[bonoboTP]

A large part of the effectiveness in counting calories is that you pay more attention and make more conscious decisions and are less likely to "cheat" if you have to enter it in your food log.

It's indeed like astrology. Simply thinking about personality traits and thinking through your life and your desires and goals and current situation is already beneficial to take charge and navigate your life.

[smallmancontrov]

I'd take the opposite point of view: just thinking about life, desires, and goals is how people wind up paying $10 to Whole Foods for a slice of "healthy pizza" that is nutritionally identical to any other pizza but comes out of a cute stone oven and is displayed on a wooden platform next to green leafy plants. Vibes astrology is notoriously easy to exploit, both by your own sugar/salt/fat-seeking instincts and by unscrupulous commercial forces, let alone the two working together. The unique thing about calorie counting is that it cannot be exploited like vibes astrology. Not even with a 20% error margin, which is (probably not coincidentally) the caloric deficit targeted by standard dieting advice.

[ijk]

That's an interesting bit, where reducing friction too much can eliminate the side effect that is actually driving the desired results.

Do you want to count calories, or do you want to lose weight? Sounds like it's possible to hyper-optimize calorie counting to the point that it becomes counter-productive...

[johsole]

Thank you for linking the study.

Some good news from it. If you weigh the food instead of depending on the package size then the labels become much more accurate!!

"Serving size, by weight, exceeded label statements by 1.2% [median] (25th percentile −1.4, 75th percentile 4.3, p=0.10). When differences in serving size were accounted for, metabolizable calories were 6.8 kcal (0.5, 23.5, p=0.0003) or 4.3% (0.2, 13.7, p=0.001) higher than the label statement."

If you look at the table "Deviation of metabolizable calories from label calories" [https://pmc.ncbi.nlm.nih.gov/articles/PMC3605747/figure/F1/] you'll see that most labels even for service side are pretty good and there are some that are really bad.

If you'll look at one of the worst offenders Tostitos, the label has "Tostitos Tortilla Chips - serving size 24 chips", but chips vary a lot in size, so you could have a huge variance in weight. If instead you weighed them, which I do with my chips, I bet the calories are much closer to the label.

Body composition comes down to routine. I've found found I love to eat, but I pretty much eat the same meals week over week, that makes it extremely easy for me to lose or gain weight depending on my goals.

[adrian_b]

Moreover, the calorie numbers for raw ingredients are much more accurate than for snack foods, where the amount of each ingredient may vary from nominal, even when the total mass is nominal.

So when you cook yourself and you weigh the ingredients used for cooking, you can know the real calorie content with far more accuracy than when buying ready-to-eat food.

[CGMthrowaway]

The errors either cancel out (if error in both directions) or they work in one direction ("bad" foods like junk systematically underestimate calories, "good" foods like protein powder systematically overestimate calories).

Either way, if you count calories and compare to your weight gain/loss over a few weeks and adjust your calorie target as warranted, assuming the types of food you are eating do not change drastically (e.g. you calibrated on regular diet and now have started an elimination diet), the error bars can be basically ignored.

[andrewvc]

Exactly! My point was that despite the precision of calories we should really think of them as ballpark estimates .

[strken]

Realistically the labels are going to be much closer for staples like long-grain Jasmine rice or olive oil, if they're measured by weight.

It's just not that easy to change the nutritional content of a kilogram of a known cultivar of dry rice when it's passed all the standard checks for moisture content, protein content, etc.

[nekusar]

Its even weirder.

What has more calories: 1 lb of peanuts, OR 1 lb of peanuts ground into peanut butter?

I cant find the study, but the peanut butter has more calories since its pre-ground and more bioavailable. Peanuts get chomped up but larger pieces still remain and are not captured by the body.

[stogot]

Does this only apply to calories or to other categories too?

[ludicrousdispla]

how many calories are in strawberry?