Discrepancy Between Self-Reported and Actual Caloric Intake in Obese Subjects | Hacker News Reader

Discrepancy Between Self-Reported and Actual Caloric Intake in Obese Subjects

nejm.org

7 pointspaulpauper12 comments

From 1992.

It’s almost always when someone says that “I’m barely eating and can’t lose weight” that they’re not counting calories accurately. Many people try to count calories using rough estimates but unless you’re putting every single thing through a scale before eating - you won’t be accurate. Even for packaged foods, calorie content can vary significantly and some articles report they can be off by up to 20%.

When I do all my bulking and cutting - I do rigorous calorie counting by never eating anything that doesn’t go through a scale. It does mean I basically never get to eat out but I’m fine with that. I’ve got goals I want to achieve.

Dr. Mike had a good discussion with a controversial figure (Jason Fung) related to all this. I would recommend watching all the way through because by the end they end up agreeing a lot more than disagreeing. There were some contentious points which I think shows a strong difference in how people think of food and weight loss. I’m very much a calorie in, calorie out guy. https://www.youtube.com/watch?v=pSwppRQ0dDQ

One of my siblings is obese and another overweight. I've been the 'skinny one' (at healthy BW/BMI/whatever) all my life. I've long suspected that if they could watch every single thing I consume in a day's time—or alternatively, allowed me to portion every single thing of theirs—they'd be shocked by the sheer difference in volume from what they've come to expect as normal.

Calorie counting aside, many, many people become strongly adapted to excessive daily consumption, and they're completely unaware that it's their root issue. It's not so much that weighing can show people how much they should be eating, but rather how much they should not be eating.

I think genes or other biological factors play a role in this though, whether it's a preference for calorie dense foods, failure to achieve satiety, slow metabolism (such as not enough NEAT), low willpower, or other factors. There are cases where the stomach empties its contents too fast, leading to hunger soon after eating, which Ozempic and related drugs help treat.

It's true—bodyweight (including obesity more specifically) definitely seems to be a multifactorial condition. I did suggest that portion size could be an identifiable 'root issue' in some cases, which is not completely accurate nor fair to say.

There is compelling evidence, from what I read online anecdotally and some studies, of obese or formerly-obese people having much slower metabolism (BMRs and TDEEs) than predicted by regression equations when controlling for body composition and weight. When someone says that “I’m barely eating and can’t lose weight” it is actually possible this may be the case. it's not just a failure to track calories when the tests show these people have slow metabolisms.

Basically, their bodies run in a sort of hoarding or efficiency mode, which although advantageous during famine, does predispose to obesity during abundance. These people got a bad genetic hand. They have to cut to absurdly low calories, and maintain it forever, to just not be obese or overweight.

The study has not been replicated and has few subjects.

    "In contrast, the subjects in group 1 underreported their actual food intake by an average (±SD) of 47±16 percent and overreported their physical activity by 51±75 percent."

I'm a dummy. Can someone explain in lay terms what that "(±SD)"/"47±16"/"51±75" stuff means?

Title of this post should probably have "(1992)" appended, too.

SD=standard deviation

The first number is the percentage, with the second being the size of the Standard Deviation from that.

On average, group 1 underreported their intake by 47% (with one standard deviation being the range of 31-66%).

They also overreported their physical intake by an average of 51% (with one standard deviation being a range of -24% to 126% overreporting).

Thank you! I think it was the just one standard deviation part that you've now clarified for me.

however, the study is old and not many subjects and afik not replicated. there are other studies that show obese children have lower than predicted metabolism for weight and body composition

It is predictable that this was a big driver. It is still sobering to see how big of a driver it is. Holy cow.

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