Dietary carbohydrate intake and mortality: a prospective cohort study (Lancet)

https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(18)30135-X/fulltext

 

Self reported questionnaires .....

 

Carbs are not bad for us. What is bad is extremism, eliminating a whole food group. I heard someone telling about her doctor recommendation (a doctor specializing in ME and similar diseases) of ketogenic diet, and I cringed. We have no good evidence. The metabolomics study is a scientific in vitro study. I am not convinced that because the citric acid cycle does not work well we should not have any carbohydrates at all. In order to conclude this, further research and scientific publication is needed. These hypothesis need to be tested, preferably with a large number of people, possibly in a controlled setting.

 

@Milo It depends on the individual, but I think it is worth it to recommend everyone to at least try ketosis or VLC and see if it helps or not. So I think that docs advice is good.

Personally my heart pounding is far worse with carbs and several people on the forums have gotten great improvement from keto, as well as with other diseases. Some people have gotten benefit from very high carb.

I tend to have the opposite opinion, that being the extremes are where you have the highest chance of benefit. If I was to put it very simplistically I would say it's easier on your metabolism to have either very high fat vlc OR very high carb vlf. Niether of which are in the study.

 

While the media predictably have jumped on the high versus low carb issue what the study actually shows (ignoring for the moment other issues such as self- and infrequently reported diets and all sorts of confounding factors) is this:
low carb with lots of meat = bad
low carb with lots of plant foods = good
In other words, whatever your macro nutrient preference, always eat your veges. Now there's an original idea

 

Their own disclaimers.

And as already noted, dietary assessment was by self-reported questionnaire - a notoriously unreliable method.

So yet another poorly designed nutritional study whose conclusions can't be relied on because of many possible confounders. Why do they keep doing them and why do journals publish them?

 

Here is a very thorough analysis of the many defects of this particular study and of the limitations of nutritional epidemiological studies in general. Here is another consideration of the general problem of these types of studies.

 

I am unable to read the whole study but meat is not the only game in town, what if it were replaced by more vegetables instead. Also what meat or what vegetables, if the predominant meat was say pork but turkey is the ticket then this study would end up suggesting that carbohydrates are superior when in fact they just used the wrong meat(s).