Does Both low- and high-carb diets raise risk of early death? Study Response

First of all, this is an observational study based on associations and these kind of studies raise more questions than answering much, if anything at all, which can cascade into falso assumptions and the land of vodoo magic. However, they can provide hints or leads that could lead to future studies but deriving conclusions or specific guidelines from these studies is a recipe for disaster.

There may be factors such as people who are actively on a plant-based diet may also be health conscious and may include other healthy habits(eg. Not smoking, not drinking, not exposing to deleterous environments, exercising etc etc.) or dietary protocols(eg. limiting disastrous types of foods) that may increase their lifespan while the people on the "higher" animal fat and protein diet may have other detrimental factors influencing their overall lifespan. It's extremely hard to tell the root cause of the problem here and this is mostly in the realm of speculation. Fun to think of and probably makes you get into Sherlock Holmes mode but that's about it.

Hypothetically, a 80-90% carb diet could mean an all potato diet with a white collar job OR a cake diet with low fat cheese, white bread, sodas, crisps, skimmed milk, 18 packs of cigarette a day and working inside a nuclear power plant. This was an extreme example but these two protocols may have the same percentage of macronutrients. However, it's hard to imagine the two diets and lifestyles have the same outcomes on lifespan and quality of life. This method of percentages is not only useless for us as a food company when it comes to creating better foods but it's also rather detrimental as it allows disastrous foods to be created that may still fit under those percentage based protocols. We need studies that give us exact compositional breakdowns of foods so that they can help us pinpoint exact problems in the foods, diet and lifestyle. More biochemistry, exact mechanisms and causes and less shooting arrows at the bulls-eye during night time... ie. less epidemiology.

It would be understandable that these studies were brushed under the mat and further led to create more targeted studies but we have the media, writers and clickbait maestros who blow it out of proportions(maybe this article too?). Clickbaits and sensationalism sells, as it pulls us from a state of normality and ignites our fight-or-flight response especially on topics that pertain directly to us or seem to be hot right now(eg. Ketogenic diets.) Mutating away the actual study to create a knee-jerk response among consumers and readers is a dirty trick played since the dawn of time. You can stop this by exercising smart consumerism and critically evaluating the article and the heart of the study itself.

If the study follows a massive group of people(aka. cohort studies) over a period of time, they are observational in nature. They show associations and no cause at all. A combination of studies to derive a conclusion(aka. meta-analysis or systematic review) that rely on such studies is usually flawed and quickly falls apart. However, they are great for ruling out causes(eg. ruling out the impact on sunlight when it comes to vitamin D levels in areas of low sunlight conditions (2)) In a simplified nutshell, such studies are usually good for ruling out a cause but dreadful for actually finding a specific cause.

Is high carb, low carb or moderate carb the problem and/or solution? It's hard to easily answer that without context of goals and the exact composition of someone's diet, environment and lifestyle choices. However, the important takeaway here was mentioned spectacularly in our podcast with Stephan Guyenet: Majority of us KNOW what is healthy for us and what's not but yet we CHOOSE to eat unhealthy, whether it's at home or social occasions. The actively healthy individuals(including you) are rather rare. How do we change that? If there are associations to be made, lets make positive associations of our role models, narratives and heroes with healthy foods and better lifestyle choices and foster a complete environment for healthy living.

(1)Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis

(2) Adequate vitamin D levels in a Swedish population living above latitude 63°N: The 2009 Northern Sweden MONICA study