Intermittent Fasting, Reality Vs Mythology
Lets talk about Intermittent Fasting
I posted this yesterday, and it led to a cacophony of responses, ranging from the appreciative to the incendiary
I did not realize that IF had taken on a kind of Sacred Cow status with some individuals and communities. People spoke of IF in near religious terms, with some people declaring themselves BELIEVERS in IF, and others confused as to how I could critique IF but also had spoken in the past about its benefits.
As I read through the comments, I realized there was ONE major critical thinking mistake everyone was making
There seemed to be this pervasive belief that Intermittent Fasting had special, near supraphysiological benefits that regular dieting did not.
There were many comments like the following, putting forth a listicle of IF benefits, and arguing why it was superior to conventional dieting strategies
Im Sorry To Disappoint Everyone, But The Benefits of Intermittent Fasting are the EXACT SAME as from regular dieting
Beyond the bro sphere, intermittent fasting has been rigorously studied the past 20 years in medicine. Its been a strategy of interest for treating obesity.
Last year, the most recent meta analysis combed through a multitude of studies and papers, and compiled the evidence. This is all publicly available information
This most recent meta analysis looked at 27 different long term and short term studies (some of them were up to 6 months in length), comparing IF to regular calorie restriction
The Good News, IF WORKED.
IF definitely produces fat loss when adhered to and a calorie deficit is created
The Not So Cool News that upset people...It did not work ANY different than regular dieting.
Nothing showed up in the meta analysis that pointed to superior effects.
The outcomes between IER (intermittent energy restriction), versus CER (continuous energy restriction), they were the same.
And I quote...
Compared to continuous energy restriction (CER), IER showed no significant long-term differences in anthropometric, cardiometabolic, inflammatory, or appetite outcomes in included studies. More long-term studies are needed to assess the benefits of IER on health outcomes
To be clear, Fasting is a viable strategy for fat loss
And to be fair, more research can be done.
But based on all the evidence available, IF works for the same reason any diet would work,
When you unfat yourself by way of reducing energy intake and burning excess bodyfat, you become metabolically healthier.
All of the benefits associated with fasting, they also occur with regular dieting and exercise. So things like....
-BDNF (Brain Derived Neurtrophic Growth Factor?-BDNF increases the most from EXERCISE, specifically with resistance training and high intensity cardio. BDNF can also increase from low carb dieting.
BDNF is also highly dependent on SLEEP. Sleep for 7-8 hours nightly and you will increase BDNF.
-Testosterone increase?-This is FALSE. Intermittent Fasting lowers testosterone in young men, it does not increase it.
What COULD increase testosterone would be losing excess bodyfat, but yet again, this would be from a calorie deficit and fat loss, not because Fasting itself did something supraphysiological
-Insulin Sensitivity?-Im repeating myself, but Insulin sensitivity and blood sugar will always improve with fat loss + exercise + higher protein diet.
-Growth Hormone Levels?-This one I will give to fasting. When you do longer duration fasts (past 20 hours), there is an increase in growth hormone production, which GH production is reduced if you are overweight.
HOWEVER, Sleep has the biggest effect on GH production (and fat loss as well!), so before thinking you need to fast to boost GH levels, fix your sleep first, that has the greater effect
-What about AUTOPHAGY?-Autophagy happens during intense exercise, which is why exercise is considered a potential therapeutic against cancer.
Could fasting kill cancer?
Not directly. Depriving cancer cells of glucose could be a therapeutic strategy, and this is being studied, but if all you had to do to "kill cancer" was fast, cancer would cease to be an issue to mortality. Obviously this is not the case, cancer is more complicated than that. Fasting might, at best, slow down cancer growth. To claim anything otherwise would be absurd
So what are the reasons to Intermittent Fast then?
Because
A) You like doing it
B) it works with your schedule and simplifies the fat loss process for you
C) It delivers results and if something is working and you have mental buy in, why stop doing it? Keep doing it if its working
D) perhaps it has some spiritual and psychological benefits that are personally meaningful (or is religiously mandated, ala Ramadan)
And if Intermittent Fasting does not appeal to you, DONT WORRY ABOUT IT. You are not missing out on anything that isnt achievable with healthy diet, routine exercise, and proper sleep.
Hopefully this was informative for everyone, any questions, post in the comments
Been down these paths so many times and indeed, IF works (but it's just caloric restriction). In combo with a predominately Paleo whole food diet, I dropped 30 kilos in 2009ish. My preferred method, rather than daily eating window, was 2x 30hr per week. From after a lunch one day, to dinner the next.
I've done various eating windows, from 18/6 to 22/2 (OMAD) at times. But yea, it's all caloric restriction no matter how you get it done.
There is one method that MIGHT be superior in terms of the general health benefits that accrues BECAUSE of the timing, rather than being only a downstream effect of the caloric restriction and fat loss.
eTRF. Skipping dinner. So, calories are front loaded for the day, and then you're done until the next day. You rarely hear about this because people shudder at the thought. "What, no DINNER!!!???" Most Shiite IFers are all about skipping breakfast, going as long as possible, many ending up munching in front of the TEEVEE every night, going to bed well-fed. It's a good area of study since it's a completely reverse approach to the same level of overall caloric restriction by means of eating window.
https://www.cell.com/cell-metabolism/fulltext/S1550-4131(18)30253-5
I stumbled upon this back in 2020 after moving to Thailand and learning about how the monks eat and how healthful looking many of them are (especially in rural areas where they adhere to their practices better, and get low-energy-density rural food...as contrasted with urban monks who get a lot of stuff from 7/11).
They eat in the early morning, then lunch around noon, and that's it for the day.
Here's a good summary article of the study.
https://www.uab.edu/news/research/item/9433-etrf-improves-blood-sugar-control-and-blood-pressure-pilot-study-says
Cheers.
One other thing (you have mentioned this in the past, just not in this letter)
If a person does IF and don't pay attention to protein, the IF diet is associated w lean muscle loss. It may be a particular problem with IF, as any people find it hard to cram in 1g/lb protein in a short window. Result: skinny-fat.
I think we are seeing the same thing happen with using GLP-1 agonists for weight loss.