Taking Nutrition Research with a grain of salt

jgnatca

Awwww. I love big pictures.

_John_

Need2Exerc1se wrote: »

_John_ wrote: »

Need2Exerc1se wrote: »

So, the author is just a journalist, right?

So only field applicable Ph.D holders are allowed to speak? Because if so I'd be happy to only discuss things on forums like this with my peers...

Yes, that's exactly what I said (not!). Geez Louise.

I find hyperbole useful. It was clear by your wording the intent was to minimize any impact from the article.

SideSteel

I just got done reading the article.

I think the conclusions and overall message (to me at least, what I took from it) was a bit strong.

We know that dietary recall methods have a pretty high degree of error and we know that the media takes study results and spins them to things that the original study didn't show.

I don't think this means we should disregard research, and while the author doesn't say "ignore all research" it certainly feels that way when I take things as a whole. That could be me not interpreting her correctly though.

Ultimately, it's important to consider the body of evidence on a given topic and how a particular study might fit within that, while recognizing strengths and limitations of any given study.

FFQs have plenty of limitations but it's not always possible to put some in a metabolic ward and provide all of the food for them.

Anyway, plenty of valid points in the article but I don't think this is any sort of rebuttal to the idea of using research to reinforce or validate a point made in discussion.

jgnatca

@SideSteel I am most grateful that you took the time to read the whole thing. What I took away is that we still know so very little about what's going on. Beef gets studied a lot because it was easy and popular, not because it's the most likely culprit. Reminds me of the old joke of the drunk trying to find his keys under a street lamp. He didn't lose them there but it was easier to look.

If we know so few things definitively, why are we doing the studies the same old way?

Doubly scary is we are making public policy decisions based on our best guesses. Banning trans fats and sugars from schools. Taxing certain foodstuffs. Building walkable cities. Labeling GMO's. Labeling foods Red/Danger-Amber/Caution-Green/Go. Will green eaters end up healthier than the rest of us?

And we are doing this on a global scale with very poor data crunching justifying all these noble efforts.

I'm with @senecarr that we need more dumb pig studies.

SideSteel

jgnatca wrote: »

@SideSteel I am most grateful that you took the time to read the whole thing. What I took away is that we still know so very little about what's going on. Beef gets studied a lot because it was easy and popular, not because it's the most likely culprit. Reminds me of the old joke of the drunk trying to find his keys under a street lamp. He didn't lose them there but it was easier to look.

If we know so few things definitively, why are we doing the studies the same old way?

Doubly scary is we are making public policy decisions based on our best guesses. Banning trans fats and sugars from schools. Taxing certain foodstuffs. Building walkable cities. Labeling GMO's. Labeling foods Red/Danger-Amber/Caution-Green/Go. Will green eaters end up healthier than the rest of us?

And we are doing this on a global scale with very poor data crunching justifying all these noble efforts.

I'm with @senecarr that we need more dumb pig studies.

I honestly don't know enough about the politics involved both in terms of government policy around nutrition, AND how funding influences study design or even general topics, so I wouldn't be able to comment on that with any experience.

I think it's accurate to say that we know very little but it's probably also accurate to say that we know a lot more than we did 50 years ago.

jgnatca

I know I've read concerns from experts in the field that some jurisdictions are going ahead with public policy without checking the evidence too carefully. Here's a call to public action (2004).

http://www.who.int/nutrition/publications/public_health_nut3.pdf

yarwell

Self reported food logs aren't the only option. Checkout receipts, CCTV, bar code scanners, trash analysis etc can tighten things up over simple recall.

jgnatca

Good point, yarwell. Volunteers would have to submit to a slightly more intrusive survey. There's also this:



http://newsroom.ucla.edu/releases/necklace-and-smartphone-app-developed-at-ucla-can-help-people-track-food-intake

Perhaps we don't have to resort to pig trials.

WalkingAlong

If self-reported food logs were useless, no one here would have lost weight. Any estimate is better than no estimate.

And using lab-fed humans in tests is too expensive so using food logs is a frequent alternative.

jgnatca

@WalkingAlong the self reported food logs are what people recollect eating, without the benefit of scales. In a controlled trial, who can know who is measuring accurately and who is eyeballing?

WalkingAlong

The same could be said of the logs here. Not everyone weighs all their food, not everyone logs correctly even if they do weigh things, not all food is exactly like the databased caloric values. It's all an estimate. Even if there was a lab-fed test group, it would still be an estimate. The '3500 calories to a pound' is an estimate, too. You don't need perfect accuracy for the info to be useful.

jgnatca

Yes, and we have varying results here on MFP. If however a researcher is attempting to answer a fundamental question, for instance, if McDonalds is truly fuelling our obesity epidemic, I want to see a little more rigour.

The data spread shows how little difference various diets make (Keto over HCLF for instance), and self reporting only makes the results more ambiguous.

If there is a magic bullet, IMO, it won't be found with dietary self reporting.