Sunday, August 30, 2015

Confirmation Bias in my head

Sometimes you get a reminder that you suffer from Confirmation Bias.

I do.

This morning I went back and dug out the study from Aberdeen:


Which carried the phrases:

"…participants were offered a fixed energy intake of 2000 kcal/d"

"In the isocaloric study, despite being served food of the same energy content, intake was slightly lower (66 kcal/d) and weight loss greater (7.2 ± 2.3 vs. 4.7 ± 1.0 kg in 4 wk, P less than 0.05), on the HF-LC diet after correction for unconsumed food"

Feed overweight men 2000kcal/d of a mixed diet and they eat it all. Feed the same men 2000kcal/d of a mildly ketogenic diet (roughly ++ on ketostix) and they refuse to eat all of the food. What they reject gives a weight loss surfeit compared to when they were on the mixed diet.

There's no evidence they went to the gym on the quiet but the study protocol probably asked them not to do this. Assuming they have gyms in Aberdeen.

I don't give a monkey's about appetite score by VAS, lack of metabolic advantage in a study using 140g/d of carbs etc. Food left on plate = Not hungry.

How much simpler can it be?

This was triggered by an article linked to by Rose Nunez Smith via FaceAche which piqued my interest and which I read right through to the end. The article kept saying things which made sense and fitted with my view of reality. There was no author on the end so I went up to the top only to find it was Gary Taubes.

Well, it made me laugh.

It's good there are people writing for the NYT Sunday Review who point out what really matters. Bugger any metabolic ward study.

BTW re Aberdeen, with ketones at ++ it would have been interesting to know what the FFA levels were like but the arithmetic cited in the study suggests we didn't have a lot of UCP activity during this few weeks of ++ ketostix eating. 

Peter

2 comments:

john said...

There are too many variables in diet/nutrition for any intelligent person get overly excited about any food trial. The fact that many low fat supporters treat that recent study as proof just shows their low quality as scientists. It happens in low carb community, too, but not as much.

You shouldn't put all your eggs in one basket, which is why this blog (proton series for example) is so excellent. Human trials, rodent experiments, generalization/theory, observation of other cultures: it's all useful.

raphi said...

Clearly, we're still in the pre-Copernican era of nutrition science :(