2006 vs 1988: BMI 2.3 higher today even when eating same diet

How accurate was their calorie counting in 1988? I know, for me, counting calories back then was laborious. Flipping through pages in a calorie counting book, I'm sure the info was not up to date.

There was another thread talking about this a while back, but beats me how to find it.

It's based on the NHANES data, which is based on recollection, and which I am skeptical about. The question is even if it's not accurate, does it still show trends accurately (the argument that the extent to which people misreport would not have changed). I don't think that's likely to be true for a few reasons.

First, although I can't quickly pull it up, my memory is that the NHANES data shows that obese people are particularly bad at reporting calories -- if you believe the information, obese people on average eat many fewer calories than people who are a healthy BMI. I don't think that's as likely to be true as the other possible explanations: they are less likely to report accurately because they are more sensitive to judgment about what they eat OR they are just worse at remembering/being aware of the calories they consume. (See, e.g., Secret Eaters, or really any study of self-estimates even while tracking to see how bad people tend to be at this.)

If you believe that, then the fact that MORE people are overweight and obese now would skew it.

There's also the question of whether people might just be worse at estimating now. I think probably so, and the reason is my own memory of the differences between now and the '80s. I think eating lots of food between meals is much more common now, high calorie foods that aren't really taken notice of/thought of as foods (i.e., high cal coffee and other drinks) are more common now, eating out IS more common now (stats indicate) and those are full of more calories than people realize, etc. So is there more room for estimating issues? I think so.

Knowing how many calories people eat is always tough, though -- there's inconsistencies between the two ways we do it, and both ways we do it aren't that accurate (NHANES and following food sold or something like that).

It seems to all be based on data from guided, but self reported, information on food and activity, which are notoriously unreliable. And outside of the recalled and reported physical activity used in the study, folks in general are less active, which effects TDEE.

Link to the actual study:
obesityresearchclinicalpractice.com/article/S1871-403X(15)00121-0/fulltext#sec0015

Firstly, everything is based on participant reporting, which makes these kinds of studies subject to perception changes over time. For example, the perception of 'moderate to intense effort' home and yard work has likely changed.

Secondly, they didn't control for basic activity levels, just moderate to intense activities performed during leisure hours (only the activities specifically named). Want to bet that not only do jobs today tend to be more sedentary than jobs in the late 80's, but so are the day-to-day lives of today vs the late 80's even if you don't look at 'leisure time activities'?

stealthq wrote: »

Secondly, they didn't control for basic activity levels, just moderate to intense activities performed during leisure hours (only the activities specifically named). Want to bet that not only do jobs today tend to be more sedentary than jobs in the late 80's, but so are the day-to-day lives of today vs the late 80's even if you don't look at 'leisure time activities'?

One of the testers who just left is an older guy, with stories about "file rooms," these places where companies had specialized furniture for storing huge quantities of paper. (Er, paper is when you cut a tree down to write on it.)

Nowadays when you want to know something about one of your customers, you interact with a mouse and a keyboard from your chair. Once upon a time, you would have had to walk to another room and go through file cabinets.

Maybe you're on to something.