NU's Quest for Carnivory!

[ATZ]

In terms of the obese, and you keep dismissing it: Dietary Misreporting.

They'll harp on about the plates of fruit and veg they eat yet miss the 10 bags of crisps and whole cheesecake they consumed on the side. It's a WAAAY bigger factor than given credit for.

[NU_nutrition_TS]

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In terms of the obese, and you keep dismissing it: Dietary Misreporting.

They'll harp on about the plates of fruit and veg they eat yet miss the 10 bags of crisps and whole cheesecake they consumed on the side. It's a WAAAY bigger factor than given credit for.

Funny how this same criticism never gets trotted out when people like Campbell use these studies to say (in opposition to their own data) that the study shows what he says it shows!

[ATZ]

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In developing his ideas about calories and obesity in
Good Calories, Bad Calories, Taubes argues that obese
individuals do not eat more than lean ones do. The data for
his belief come from the Diet and Health Report (16)
prepared by the National Academy of Sciences. This report
said ‘Most studies comparing normal and overweight
people suggest that those who are overweight eat fewer
calories than those of normal weight’. Further on, the
author says ‘Even if it could be established that all obese
individuals eat more than do the lean – which they don’t –
that only tells us that eating more is associated with being
obese’. As a member of the committee drafting the Diet and
Health Report, I was responsible for writing this section.
The data used in this report were based on food-intake
records and reflected the information of the day. Even then,
however, there was a paradox. Measurements of energy
expenditure using oxygen consumption showed a nearly
linear increase in energy expenditure as body weight
increased. This meant that heavier people were expending
more energy than were leaner ones. How did the over-
weight people keep up their higher energy expenditure if
they did not ingest more food?

We now know that the data used in the Diet and Health
Report were wrong and that obese people eat more food
energy than do lean ones. The answer to this apparent
paradox came from a new technique for measuring total
daily energy expenditure (17). This technique allows us to
measure total energy expenditure over an interval of
7–10 days and cannot be influenced by the subjects’ food
intake. As information obtained from this technique began
individuals do not eat more than lean ones do. The data for
to appear, it was compared with the information from food
records. The data showed that normal-weight people
underreport what they eat by 10–30%. This means that
dietary food-intake records underestimate energy expendi-
ture by nearly a quarter. For overweight people, the degree
of underreporting is higher, varying from 30% to 50%.
Thus, food records as a measure of ‘real’ calorie need are
unreliable, as for any individual you do not know how
much he or she actually underreports. Moreover, underre-
porting seems to be higher for dietary fat (18). When food-
intake records are used, the greater discrepancy reported by
the obese would make their data closer to those of normal-
weight people who underreport less. The data on energy
requirements based on doubly labelled water measure-
ments from many laboratories were compiled in the Rec-
ommended Dietary Intakes (19), one of the sources that are
not cited in Good Calories, Bad Calories. Table 2 compiles
some of these data. The body mass index (BMI) is 5–7 units
higher in the overweight group than in the normal-weight
group and the overweight men expend 300–500 calories
more per day than do the normal-weight men, meaning
that they must eat more food just to maintain their weight.
The women are even heavier, with a 6- to 10-unit BMI
difference and energy expenditures that are 100–500
calories more per day. To maintain this extra weight the
women have to eat enough food to provide this extra
energy.

People WANT to appear healthy - they'll report all that fruit and veg but not all the other crap, including the much maligned dietary fat they (wrongly) believe to be unhealthy.

[ATZ]

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Funny how this same criticism never gets trotted out when people like Campbell use these studies to say (in opposition to their own data) that the study shows what he says it shows!

Campbell of "The China Study" Fame / Misfortune?

[NU_nutrition_TS]

!0-30% under-reporting for normal-weight people vs. 30-50% under-reporting for overweight people. So there is a cross-over area there where the degree of under-reporting is equal. In the numerous studies done over the years this still indicates there is a discrepancy between calories in/out and body mass that cannot be explained away by the 'calorie is just a calorie' principle.

Also what about the epidemiological/longitudinal studies where intakes of various foods are gauged by methods other than dietary questionnaires (or those methods are used to reinforce data from dietary questionnaires) such as looking at population expenditure/wastage figures, shopping habits, retail sales, etc.?

I think there is far too much smoke for there not to be some burning embers buried amongst all this data.

[ATZ]

Hmm, I'm not so sure there is that much cross over there...

30% represents the highest that normal weigh people will underreport ,and the MINIMUM a fat person will underreport. That to me suggest that majority of normal weight people will underrepot by less than 30% while the majority of overweight people will underreport by more than 30%, somewhere in the region of 30-50%. Unless my grasp of stats is waaay off.

That's not to say that higher intake of fruit and veg may not be a causation of obesity either, just there's more to the picture than you're painting.

[NU_nutrition_TS]

So you are totally eliminating the possibility that the normal weight people may under-report at the top of their range while overweight people may under-report at the bottom of theirs, i.e., both by 30%? How convenient for you!

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These are just some of the problems that come from manipulating the macronutrients and calories. There are other problems as well. If we give subjects diets and tell them to follow them on their own, then the specter of underreporting is involved. If we put subjects in metabolic wards, the expense of the study increases exponentially. And, contrary to what some people think about metabolic wards, these are not lock-down units, but are simply beds in a hospital designated for the study. As often as not, subjects in metabolic ward studies are free to go to their jobs during the day or roam around the hospital at will and have visitors. Subjects cheat during metabolic ward studies, and are probably less prone to admit it than they are on free-living studies. All in all, it’s difficult to get good reliable data from any kind of diet study. So, we’ve got to live with what we can get and make the best judgments we can.

Low-carb diet improves lipid profile better than low-fat diet | The Blog of Michael R. Eades, M.D.

[ATZ]

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So you are totally eliminating the possibility that the normal weight people may under-report at the top of their range while overweight people may under-report at the bottom of theirs, i.e., both by 30%? How convenient for you!

Not at all, without looking at the data those above inferences are based on I don't honestly know, but you too are speculating Nu.

The results could show that the majority of normal weight people only underreport by say 10% with a few up at the 30%'ile, while the overweight are in the majority well above that level closer to the 50% mark with again only a few closer to 30%. They might suggest a trend closer to what you have suggested. I'll see if I can dig out the actual data.

Fact is, dietary underreporting cannot be ignored just becaue of this. If things tied in with your theory of the above then normal weight people should be just as fat as the obese as they're both underreporting to similar degrees, fact is they're not.

You'll no don't see this as ammo to support your carb hypotheisis however, which puts us back at square one.

[NU_nutrition_TS]

You seem to be missing the point: As Dr Eades pointed out, you will never get a truly accurate account of total calories consumed and ratio of macronutrients in ANY dietary study of any significant number of participants - metabolic ward or not - because they are ALL capable of being influenced by some degree of under-reporting/cheating. You have to work with the data you have no matter how it is arrived at.

It just seems to me that the dietary under-reporting 'trump card' is only ever dealt by those seeking to undermine the wealth of evidence in favour of low carb/high fat diets or against the favoured low calorie, low fat, high carb diets (vegetarian/vegan) for whatever health outcome you wish to look at!

The fact remains the conclusions of the China Study were in direct contradiction to the actual data. And incidentally, according to several studies I have reviewed on this phenomenon, the one dietary factor not influenced by under-reporting is fruit & veg consumption!

[ATZ]

So you'd argue that the obese never underreport? We all know this to be fallacy from all the fat programs on tv. When they actually sit down and look at what they eat it's vastly in excess of a normal person, even if they swear blind to be existing on low cals.

I'm not gonna argue the health benefits of low carb and I don't know enough about the china study without further reading. Fruit and veg may well be correlated with obesity but there's plenty of good data to show them to be healthful also.