Shocking Results! 1st Ever Human Controlled Trial on Intermittent Fasting - Doctor Reacts

Summary

In this video, Dr. Eric Westman reviews and debunks popular nutritional information, focusing on intermittent fasting (IF) and its benefits. He contrasts different fasting approaches, including a recent study comparing time-restricted feeding (6-hour and 12-hour windows) without caloric restriction. The study showed significant improvements in insulin sensitivity, pancreatic function, and oxidative stress reduction. Dr. Westman emphasizes the importance of considering macronutrient ratios in fasting studies and promotes a low-carb, high-protein approach, suggesting that IF works best when combined with a ketogenic or low-carb diet for optimal fat-burning benefits.

Takeaways

• 📢 Dr. Eric Westman discusses a fasting study that questions the effectiveness of intermittent fasting compared to caloric restriction.
• 🎥 The video features Tom Lower, an internet influencer in the keto, low-carb, fasting, and carnivore diet space, reviewing studies on intermittent fasting.
• 🥤 Dr. Westman promotes Element, an electrolyte supplement suitable for keto diets, highlighting its lack of fillers, sugar, artificial colorings, and gluten.
• 🔍 The study in question is a controlled feeding trial that compared a six-hour eating window to a more traditional eating schedule without caloric restriction.
• 📉 The study found that insulin sensitivity and beta cell function improved with a more aggressive fasting window, suggesting benefits beyond simple caloric restriction.
• 🍽️ Intermittent fasting is often misunderstood; it doesn't dictate what to eat during eating windows, which is crucial for health outcomes.
• 📉 Studies on intermittent fasting often involve a diet high in carbohydrates, which may not align with the nutritional ketosis approach.
• 🌟 A significant finding was a decrease in reactive oxygen species with aggressive fasting, which could impact aging and longevity.
• 📉 The study showed that even with equal caloric intake, fasting led to a decrease in appetite, challenging the conventional belief about eating frequency and hunger.
• 🔄 The video suggests that more aggressive fasting may have more significant benefits than mild fasting, such as 14-hour daily fasts.
• 📚 Dr. Westman concludes by advocating for flexibility in diet timing while emphasizing the importance of low carbohydrate intake for the benefits of fasting and keto diets.

Q & A

What is intermittent fasting according to the video?

Intermittent fasting is a dietary approach where you eat less often during the day. For example, if you eat once a day, it's considered a 24-hour fast. It generally means restricting the eating window, like eating within 6 or 12 hours, and fasting for the remainder of the day.

How does intermittent fasting differ from caloric restriction?

Intermittent fasting focuses on when you eat rather than how much you eat, while caloric restriction emphasizes reducing the total amount of food consumed. Both approaches can lead to similar weight loss results, but intermittent fasting also focuses on timing, which may have additional metabolic benefits.

What was unique about the study discussed in the video?

The study compared time-restricted feeding with a 6-hour eating window to a 12-hour eating window. Both groups were given enough calories to maintain their weight, and the study was carefully controlled to ensure equal calorie intake. The results showed improvements in insulin sensitivity and reduced oxidative stress in the 6-hour group.

What are the benefits of intermittent fasting highlighted in the study?

The study found that intermittent fasting improved insulin sensitivity, beta cell function, and pancreatic function. It also reduced reactive oxygen species (ROS), which are linked to oxidative stress and aging. Additionally, participants experienced a reduction in appetite even though they were eating the same amount of food.

Why is insulin sensitivity important in the context of intermittent fasting?

Improving insulin sensitivity allows the body to better manage blood sugar levels, reducing the risk of developing insulin resistance or type 2 diabetes. The study demonstrated that time-restricted feeding helped improve insulin sensitivity, which is a key metabolic benefit.

How does the macronutrient composition of the diet affect fasting studies?

Many fasting studies are conducted with a diet that consists of 50% carbohydrates, 30% fat, and 20% protein. Dr. Westman points out that these studies often don't explore low-carb or ketogenic diets, which he believes would show different metabolic effects. Macronutrient breakdown plays a significant role in determining the outcomes of fasting.

What is Dr. Westman's perspective on low-carb and keto diets in relation to fasting?

Dr. Westman advocates for low-carb or ketogenic diets, emphasizing that they shift the body into a fat-burning state (nutritional ketosis). He suggests that combining intermittent fasting with a low-carb diet might enhance fat burning and health benefits, but more studies are needed to confirm this.

What does the video say about the reduction in appetite during fasting?

The study found that participants who followed time-restricted feeding experienced a reduction in appetite, even though they were required to eat enough to maintain their weight. This suggests that fasting can naturally reduce hunger, possibly due to changes in hormones or the body's adaptation to less frequent eating.

Why is the decrease in reactive oxygen species (ROS) significant in the context of fasting?

Reactive oxygen species (ROS) are byproducts of metabolism that can cause oxidative stress, which is associated with aging and various diseases. The study found that more aggressive fasting reduced ROS, suggesting that fasting may help slow down aging and improve overall cellular health.

What is the role of autophagy in fasting, according to the video?

Autophagy is the body's process of repairing and recycling damaged cells and tissues. Fasting helps trigger autophagy by giving the body a break from processing food, allowing it to focus on healing and repair. This cellular cleanup process is considered one of the key benefits of fasting for long-term health.

Outlines

00:00

📚 Intermittent Fasting and Caloric Restriction Study Overview

Dr. Eric Westman introduces a discussion on a fasting study that suggests no difference between fasting and caloric restriction. He sets the stage for an evaluation of Tom Lower's review of studies on intermittent fasting. Dr. Westman also promotes Element, an electrolyte supplement suitable for keto diets, and highlights its benefits and offering a free sample pack for his listeners. The paragraph ends with a mention of another study that looked into more aggressive fasting.

05:03

🔍 In-Depth Analysis of Aggressive Fasting Study

This paragraph delves into a study that compared the effects of a six-hour eating window versus a 12-hour window on subjects who were fed enough calories to maintain their weight. The study, published in Cell Metabolism, found improvements in insulin sensitivity and a decrease in reactive oxygen species, which could impact aging. Dr. Westman points out that most intermittent fasting studies focus on a diet high in carbohydrates, which differs from a nutritional ketosis diet.

10:05

🍽️ The Impact of Intermittent Fasting on Appetite and Autophagy

Dr. Westman discusses how the study showed a decrease in appetite even though subjects were eating the same amount of calories. He explores the idea that eating less frequently allows the body to heal through autophagy and reduce oxidative stress. The paragraph also touches on the historical and religious significance of fasting and its potential therapeutic benefits.

15:07

🔬 Conclusions from Fasting Studies and Practical Recommendations

The final paragraph summarizes the findings of the fasting studies and suggests that more aggressive fasting may be beneficial. Dr. Westman recommends flexibility in eating patterns while adhering to a low-carb diet for the benefits of nutritional ketosis. He expresses interest in seeing a study comparing one-meal-a-day intermittent fasting within a low-carb diet to multiple meals within the same dietary context.

Keywords

💡Intermittent Fasting

Intermittent fasting refers to an eating pattern that cycles between periods of eating and fasting. In the video, Dr. Eric Westman explains that intermittent fasting can be as simple as limiting eating to a specific window of time, such as six or twelve hours. It is a core concept in the video, with various studies reviewed to compare the effects of intermittent fasting with caloric restriction on weight management and metabolic health.

💡Caloric Restriction

Caloric restriction involves reducing calorie intake without malnutrition, often used in studies to measure its effects on weight loss and health. The video compares fasting to caloric restriction and notes that both approaches yield similar results in some studies. The key point is that fasting isn’t necessarily superior unless done more aggressively, as shown in some research discussed.

💡Insulin Sensitivity

Insulin sensitivity refers to how effectively the body's cells respond to insulin. In the video, Dr. Westman highlights a study where more aggressive fasting improved insulin sensitivity, allowing the body to process carbohydrates better. This improvement in metabolic function is one of the primary benefits of intermittent fasting, as seen in reduced blood sugar levels and better pancreatic function.

💡Reactive Oxygen Species (ROS)

Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen, often linked to cell damage and aging. Dr. Westman discusses a study showing that fasting reduces ROS, which contributes to lower oxidative stress and potentially slows aging. This is a significant finding in the context of fasting's impact on longevity and cellular health.

💡Macronutrients

Macronutrients refer to the three main types of nutrients: carbohydrates, fats, and proteins. The video repeatedly emphasizes the importance of macronutrient composition in diets, with Dr. Westman pointing out that many fasting studies use diets high in carbohydrates (50%), which may skew results. He argues for a focus on protein and lower carbohydrate intake, especially in ketogenic or low-carb diets.

💡Nutritional Ketosis

Nutritional ketosis is a metabolic state in which the body burns fat for fuel instead of carbohydrates, typically achieved by following a low-carb, high-fat diet. Dr. Westman advocates for combining intermittent fasting with a keto diet to enhance fat-burning benefits, criticizing studies that don’t account for this key factor when examining fasting outcomes.

💡Time-Restricted Feeding

Time-restricted feeding is a type of intermittent fasting where individuals limit their eating to a specific window of time each day. In the video, a study comparing a six-hour eating window to a 12-hour window is discussed. The study showed that despite the same caloric intake, the six-hour group saw better results in insulin sensitivity and appetite reduction, showcasing the benefits of more aggressive fasting.

💡Autophagy

Autophagy is the body's process of cleaning out damaged cells to regenerate newer, healthier ones. Dr. Westman refers to this natural process when explaining the benefits of fasting. By not eating frequently, the body can focus on repairing itself, promoting better cellular health and potentially slowing aging.

💡One Meal a Day (OMAD)

OMAD, or One Meal a Day, is an extreme form of intermittent fasting where individuals only eat once a day, effectively fasting for 24 hours. Dr. Westman mentions this as an example of aggressive fasting, suggesting that while some may find success with it, it’s important to focus on the nutritional quality of the food consumed during that meal.

💡Oxidative Stress

Oxidative stress occurs when there is an imbalance between free radicals (such as ROS) and antioxidants in the body, leading to cell damage. The video highlights how aggressive intermittent fasting reduces oxidative stress, which is linked to aging and various diseases. This reduction is seen as one of the critical health benefits of fasting.

Highlights

Dr. Eric Westman reviews and debunks nutritional information, focusing on fasting and caloric restriction comparisons.

The video includes discussion on intermittent fasting, keto, and other diets, highlighting their potential health benefits.

Element, a sponsor of the video, provides a mixture of sodium, potassium, and magnesium, which Dr. Westman uses and recommends for keto diet followers.

Intermittent fasting means eating less and less often; the term refers to any pattern where you reduce the frequency of eating, such as OMAD (One Meal A Day).

Dr. Westman emphasizes that there are many healthy dietary approaches, and intermittent fasting is just one option for weight loss and health improvement.

The recent study published in Cell Metabolism compares time-restricted feeding (6-hour eating window) against a longer 12-hour eating window with equal calories.

The study shows that insulin sensitivity, pancreatic function, and beta cell function improved significantly over a five-week period.

Reduction in reactive oxygen species (ROS) and oxidative stress was observed, indicating benefits for aging and overall longevity from time-restricted feeding.

Eating less frequently allows the body to heal and undergo autophagy, where the body repairs itself; this is a core benefit of fasting.

The appetite of participants decreased in the time-restricted eating group, even though they maintained their calorie intake for weight maintenance.

Cross-over design of the study showed that switching from a 12-hour to a 6-hour eating window yielded the same beneficial effects.

Short-term, aggressive fasting three times a week may be more effective for achieving health benefits, compared to more moderate fasting like 14-hour windows.

Most studies cited involve diets with 50% carbohydrates, which limits their ability to represent low-carb or keto diets properly.

Dr. Westman promotes eating a low-carb keto diet for flexibility and fat burning, without strict adherence to intermittent fasting if it doesn't suit the individual.

The focus on low-carb diets helps the body remain in a state of nutritional ketosis, which supports fat burning and offers similar benefits to fasting.

Transcripts

while the whole world and the whole

internet has been talking about this

fasting study that came out that shows

that fasting and caloric restriction are

no different in terms of end result what

is intermittent fasting and should you

be doing

[Music]

it hi I'm Dr Eric Westman and welcome to

my channel where I review and debunk

nutritional information online in this

video thanks for sending them I'm going

to be listening to Tom lower Tom is a

massive internet influencer in the keto

low car fasting space carnivore at times

and he's going to be reviewing some

studies about intermittent fasting be

sure to wait till the end till you get

my final thoughts I want to thank our

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Eric Westman this offer is only

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slair Westman you'll find that in the

description below thank you element for

sponsoring this this video there's

another paper that was published that

nobody was really talking about that

actually looks at real more aggressive

fasting what do I mean by that well the

previous study and I've done some videos

on this that takes a look and says

fasting is the same as caloric

restriction although I agree with

everything it said everything nothing I

disagree with well-crafted study it was

looking at very shortterm like fasting

periods or very short fasting periods

rather it was very was like 14-hour

fasts which I don't know but without

even thinking about it I fast for 14

hours and a lot of people do so well so

what is intermittent fasting and what is

fasting and there's a lot of jargon that

goes on here you know you don't have to

do intermittent fasting uh although I'm

finding into the keto or even weight

loss world people enter through

different doorways if you will and then

uh or like you're going into a vendor

area at a meeting if you come in and the

first Booth you see is intermittent

fasting and you do it you might think

that's the only thing that is available

and certainly promoters of different

diets or different techniques only talk

about their technique typically because

they are most familiar with that or they

make money from that technique or sell a

book that sort of thing but there really

a lot of ways to go about being healthy

I believe and intermittent fasting and

or keto or carnivore or ultra low fat

diets they all can be healthy what you

want to do is match your metabolism to

the level of carbohydrates in the diet

from my perspective so what is

intermittent fasting well several

internet influencers started talking

about fasting and and in general it

means eating less and and eating less

often during the day so if you eat once

a day that's a 24-hour fast because

you've gone 24 hours without eating

anything because you've eaten just one

meal a day you might have heard that as

omad om mad d one meal a day but what

intermittent fasting doesn't tell you

and one of the problems that we're going

to see in this video is what are you

going to eat during that that window of

period of time and that's going to be

critical when you're looking at these

studies hang on so this study was the

first clinically supervised controlled

feeding trial in humans on fast to

compare if Tim restricted feeding in a

more aggressive sense like a six-hour

eating window if calories are equal has

any benefit very interesting findings so

this study was published in cell

metabolism and what's cool is they gave

subjects enough calories to maintain

their weight okay so it went on for for

5 weeks okay and it was a crossover

design so when one group finished the

other group went into the other arm so

what's interesting about this study is

they didn't put them on a caloric

restriction they didn't even like match

calories what they did is they said hey

here's exactly what this person needs to

maintain their weight exactly and here's

what this person needs to maintain their

weight and this person it was so

designed to a te clinically supervised

and absolutely like literal to the tee

feeding to make them keep their weight

and it worked well that's a great

setting up of of the study very

controlled and uh what is missing is

what what did they eat so looking at the

the study itself and and actually all

the other intermittent fasting studies

that are done by funded funded meaning

researchers who get grants to fund it

they all are studying a 50% carbohydrate

diet when people eat it's remarkable it

it's 50% carbs 30% fat and 20% protein

so I have to editorialize that the

studies that they're being referenced

here are all intermittent fasting

studies but they're 50% carbohydrate 30%

fat 20% protein so at a basic level what

you want to do when you're looking at a

study just look at the macros percent

macros as Jeff volik has said many times

when you're eating a nutritional ketosis

type of diet carbohydrate isn't a

macronutrient it doesn't have to be but

I've learned that just as a summary

measure look at the percentage of the

daily calories is 50% carbs 30% fat 20%

protein in this paper and whether you

call it a Mediterranean diet or whatever

but you want to get that macronutrient

break down and this one it was 50% carbs

18% protein 30% fat for Tim restricted

feeding study in this one 50%

carbohydrate 30% 5% fat 15 you getting

the point these aren't really studies of

nutritional ketosis so Tim restricted

feeding or intermittent fasting doesn't

really say anything about what you eat

during that time although these are all

junk fruit free sorts of diets because

it's a these are research studies but

when you're looking at information about

what to eat I want you to eat protein

we're made of protein protein it should

be protein first in your thinking and

then the macros if you're doing a diet

of nutritional ketosis type you're

usually 5% of your daily calories is

carbohydrate or maybe 10% and then

that'll depend on how much you're eating

for the day but to look at these

research papers it's interesting some of

them didn't even put the that

macronutrient breakdown in the abstract

so you have to go into the method

section to see exactly so basically

we're we're here now summarizing we're

talking about eating carbs once a day

well they did that so one group ate in a

six-hour aggressive fasting window okay

they couldn't eat past 300 p.m. the

other group ate in a 12-hour block but

remember it didn't matter with calories

because it was all equal macros were

equal spacing was obviously different

but as close to equal as they could get

in terms of the sequencing okay so the

only thing that was different was the

timing period no calorie difference

individually as a percentage or

relatively speaking here's what they

found insulin sensitivity improved who

have thought you take a break from food

insulin sensitivity is going to improve

but insulin sensitivity didn't just

improve in the short term beta cell

function improved pancreatic function

improved so over a 5we period they had

significant improvements in just the

ability to process carbohydrates and

manufacture insulin okay well guess what

else happened there was a decrease in

reactive oxygen species species this is

fascinating to me because reactive

oxygen species is a driver of Aging okay

so from a longevity perspective for a

long time for like the longest time up

until probably 15 years ago 10 years ago

we thought that reactive oxygen species

Ross oxidative stress was the primary

driver of Aging it could still be a

primary driver but we've since found a

lot of other things that are driving it

okay mitochondrial stuff that's beyond

that but Ross is still a big one

oxidative stress the fact that just

compressing eating Wom in an aggressive

time reduced Ross is very interesting

oxidative stress went down but who would

have thought if you stop eating for a

little bit maybe you give yourself a

chance for endogenous antioxidants to

actually do the job and that's I think a

good sort of paradigm shift that's

occurring that you don't have to eat

three four five meals a day breakfast is

not necessarily the most important meal

of the day which the cereal Manu

facturers would love you to believe so

eating less often allows your body to

heal itself to repair itself I think you

know fasting has been part of every

major religion as a therapeutic or

healing process uh even kind of even

spiritually to to be uh aesthetic or or

to get real rid of worldly sorts of of

connections you don't have to think of

it in that way but it's more just

letting your body heal itself autophagy

is the repair of your own body so you

don't have the inputs coming in that you

have to deal with eating is a stress and

you don't have that stress when you're

not eating even in the context of eating

carbs once a day as these studies are

showing I love this study because it's

just it's really hard to poke holes in

it the other thing that's interesting is

that appetite went down even though they

had to eat the same amount appetite went

down right so they were maintaining

weight but they had less desire to eat

but they ate anyway because they had to

because they were eating to maintain

weight but they actually didn't even

want to eat that much so it's like some

would say well the benefits of

intermittent fasting as far as the

consumption is concerned and the lack of

appetite comes because you're

restricting your stomach shrinking and

that could be true but in this

particular case they were feeding them

just enough to maintain weight and they

still had a reduction of appetite so you

know I've seen that clinically as well

where or heard that where people will

tell me that if they have breakfast it

makes them more hungry during the day

and they eat more now that's not true

for everyone let me know your your

response down below it does breakfast

make you want to eat more or eat less so

the classic teaching is that our our

system is like a gas tank on a car and

that you fill up until you're full and

so eating shouldn't make you want to eat

more although some people tell me that

which kind of makes sense sort of from a

standpoint of If You Came Upon an animal

or you killed an animal a dead animal

you had to eat it because it would spoil

it was only relatively recently that we

we as humans learned how to preserve the

food so eating might make you want to

eat more in that context there there

shouldn't be a break uh on how much you

eat uh if you couldn't have it you know

an hour later so to for example uh so I

wonder what your response is does

breakfast make you want to eat more of

course in the context of a low carb diet

please so there's a good chance that

even after the study maybe they would

continue to lose weight but it gets

better in the fact that they crossed

over and those that did the 12-h hour

went to the 6 hour and they had the same

effects so it was like double proven in

this metabolic like supervised situation

the thing that makes me happy about this

study is this one actually looked at

real fasting compared to some of these

other studies that are looking at 12

hours or 14 hours or sometimes even 16

hours that's just not enough time and

I've preached this for so long and yes

I'm toting my horn here but I have like

if you want the benefits of fasting you

need to go more aggressive the caveat

with this is I don't think everyone

should just model this this was a

controlled situation for 5 weeks which

is about as far as I would probably push

it in this case before it might be too

much fasting however calories were set

to keep the metabolism somewhat high so

maybe it would be okay if you were doing

it this way but the shortterm like three

times a week more aggressive fasting is

probably the way to go and I think this

kind of study demonstrates that compared

to the other study that was published in

the anals of internal medicine just a

couple of weeks ago that says like hey

14-hour fasts every day don't do that

much however let me make a note and I

talked about this in that other video

that broke that study down a 14-hour

fast still showed improvements in

insulin resistance in their home IR it

wasn't highlighted in a lot of people's

reviews of that study because it was

statistically insignificant but when you

actually look at the literal graph it's

pretty darn significant and if you know

scientific journals at all you know that

statistically significant and absolute

significance in like what it actually is

in real life is a little bit different

because it's more about the parameters

that are set on the study versus the

actual outcome so it means that it was

not statistically significant beyond

what was pretty much expected but it was

still significant enough to say hey it's

significant bottom line it works see you

tomorrow so these studies and the the

NIH researchers I I recall doing

intermittent fasting studies are using

carbs during that one meal a day when I

teach a low carb keto diet I teach

flexibility if you want to eat more

frequently you can if you want to eat

three meals a day you can but you have

to stay away from carbs what happens

there is your body goes into nutritional

ketosis just changes metabolism to fat

burning it's just same way to say it and

that can have healing effects in and of

itself it would be great to see a study

of intermittent fasting one meal a day

in the context of a low carb diet versus

those who eat multiple times a day in

the context of a low carb diet I haven't

seen that study done yet so I'm still

teaching now to let your body tell you

when to eat use flexibility in the

timing but stay away from the carbs as

the general rule and you're going to get

the benefits of fasting of not eating

because that is really fat burning so

fat burning is what happens when you're

fasting and so when you're not eating so

much you're going into fat burning and

that's what happens all the time when

you're eating a low carb keto diet I

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