The Mediterranean diet study [0] is correlation analysis, not causation. As in, the purported vicious cycle may not exist, but both may be symptoms of something else.
I skimmed the 4h/night study too. [1]
Not sure whether it holds up. People eat a little more if they sleep half as much. Maybe people generally bad at avoiding hunger cravings, and more time awake means more giving into cravings?
"People consistently eat while awake" wouldn't be a good paper, I guess.
(I have to ask whether the purported 20g more fat is a typical amount for a meal, 8g more saturated fat. That's butter, lard, cheese, cured meats.)
EDIT: I looked at the Fiber intake paper too [2]. The dataset from the origin study excludes so many people (such as poor sleep quality people?) I wonder who is left:
> Some exclusion criteria included shift work or any work that required frequent travel across time zones, metabolic disorders such as type 2 diabetes, cardiovascular disease, and hypertension, smoking, and eating disorders, sleeping disorders, or neurological disorders. Further exclusion criteria included the use of medication, including benzodiazepines, antidepressants, and other medications for insomnia. The presence of sleep disorders, excessive daytime sleepiness, and poor sleep quality were also exclusionary, and were assessed with the Sleep Disorders Inventory Questionnaire, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index, respectively.
Not to say this is p-hacking, but excluding people who report poor quality sleep seems very odd for someone recommending diets to improve sleep.
The author also says stuff in there like "Clinical studies have shown that sleep restriction leads to increased energy intake, energy intake from snacks, and intake of energy-dense foods." yet their citations are both correlation analysis.
Yes, the causation is poorly disentangled. He says:
"In our research, those who followed [a healthy, Mediterranean style diet] were 1.4 times more likely to have good night’s sleep and 35 percent less likely to have insomnia."
One naturally thinks "people who have healthy diets probably also make other healthy lifestyle choices, which may be the cause of the better sleep".
I skimmed the 4h/night study too. [1]
Not sure whether it holds up. People eat a little more if they sleep half as much. Maybe people generally bad at avoiding hunger cravings, and more time awake means more giving into cravings?
"People consistently eat while awake" wouldn't be a good paper, I guess.
(I have to ask whether the purported 20g more fat is a typical amount for a meal, 8g more saturated fat. That's butter, lard, cheese, cured meats.)
EDIT: I looked at the Fiber intake paper too [2]. The dataset from the origin study excludes so many people (such as poor sleep quality people?) I wonder who is left:
> Some exclusion criteria included shift work or any work that required frequent travel across time zones, metabolic disorders such as type 2 diabetes, cardiovascular disease, and hypertension, smoking, and eating disorders, sleeping disorders, or neurological disorders. Further exclusion criteria included the use of medication, including benzodiazepines, antidepressants, and other medications for insomnia. The presence of sleep disorders, excessive daytime sleepiness, and poor sleep quality were also exclusionary, and were assessed with the Sleep Disorders Inventory Questionnaire, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index, respectively.
Not to say this is p-hacking, but excluding people who report poor quality sleep seems very odd for someone recommending diets to improve sleep.
The author also says stuff in there like "Clinical studies have shown that sleep restriction leads to increased energy intake, energy intake from snacks, and intake of energy-dense foods." yet their citations are both correlation analysis.
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6231522/
[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3142720/
[2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702189/