Why Longevity Experts Are Warning Against Fasting

Summary

This video explores the evolving views on fasting, particularly the shift from initial enthusiasm based on rodent studies to a more cautious stance informed by human clinical trials. It discusses the benefits of time-restricted feeding, such as weight loss and improved blood sugar control, and addresses the critical flaw in studies that compared calorie-restricted groups. The video also highlights the importance of protein intake during fasting and the potential muscle loss from prolonged fasts. It concludes with practical advice on integrating time-restricted feeding into a healthy diet and cautions against multi-day fasts due to muscle degradation.

Takeaways

• 🔬 The initial excitement for intermittent fasting came from rodent studies showing benefits like weight loss and increased lifespan, even without calorie restriction.
• 🧬 Autophagy, the cellular process of clearing away damaged components, was observed in rodents during fasting, suggesting potential health benefits.
• 🧐 Human clinical trials have shown that the benefits of time-restricted feeding are largely due to calorie restriction rather than the fasting itself.
• 📉 A meta-analysis by the Cochran organization found no differences in weight loss or blood sugar levels when calorie intake was matched between fasting and non-fasting groups.
• 🏋️‍♂️ Concerns about muscle loss during prolonged fasting have led experts like Dr. Peter AA and Dr. Ronda Patrick to reconsider their stance on fasting protocols.
• 🥤 To maintain protein intake and support muscle building, it's recommended to include a low-calorie protein shake in the diet, especially during periods of fasting.
• ⏰ The timing of meals is important; having a large breakfast and medium lunch with a small early dinner, followed by a period of no eating, can be beneficial for sleep and recovery.
• 🦵 Muscle is crucial for health, and multi-day fasts can lead to significant muscle loss, which is why they are advised against in the script.
• 📚 The video emphasizes the importance of protein intake and encourages viewers to explore further content on optimizing protein consumption for health.
• 🙏 The video concludes with a thank you to patrons for their support, highlighting the community aspect of health education.

Q & A

Why did Dr. Peter Attia and Dr. Ronda Patrick change their stance on fasting?

Dr. Peter Attia and Dr. Ronda Patrick changed their stance on fasting due to new human clinical research that suggests there is no additional benefit from time-restricted feeding beyond calorie restriction.

What was the initial excitement for intermittent fasting based on?

The initial excitement for intermittent fasting was based on studies in rodents that reported time-restricted feeding reduced body weight, improved blood sugar control, lowered insulin levels, and increased lifespan.

What is autophagy and how is it related to fasting?

Autophagy is the cellular process where old, damaged components are cleared away to make room for new components. It was observed in rodents during fasting periods and was thought to contribute to the health benefits of time-restricted feeding.

What is the critical point about the rodent studies on fasting?

The critical point is that even when food intake was matched to the control group, rodents who ate within a smaller time frame lived longer, suggesting potential benefits beyond just calorie restriction.

What flaw was found in most human studies on time-restricted feeding?

The flaw found in most human studies on time-restricted feeding is that the groups practicing time-restricted feeding typically consumed fewer calories compared to the control group, making it difficult to isolate the effects of fasting from calorie restriction.

What did the 2020 meta-analysis of human studies on time-restricted feeding suggest?

The 2020 meta-analysis suggested that time-restricted feeding offered greater weight loss and reductions in blood sugar levels compared to diets where people could eat whenever they wanted.

Why did Dr. Attia stop his multi-day fasts?

Dr. Attia stopped his multi-day fasts due to a lack of good human evidence supporting their long-term benefits and concerns about muscle loss, which he felt was not worth the potential benefits.

How does muscle loss relate to fasting practices?

Muscle loss relates to fasting practices because prolonged fasting can lead to the breakdown of muscle tissue, which is difficult to rebuild, leading to a net loss in muscle mass and strength.

What is the recommended approach to time-restricted feeding according to the script?

The recommended approach to time-restricted feeding is to ensure adequate protein intake to support muscle health, possibly by including a low-calorie protein shake during the fasting period.

Why are multi-day fasts discouraged in the script?

Multi-day fasts are discouraged due to their impact on muscle stores, which are considered too important to waste away, and the lack of evidence for long-term benefits.

What is the significance of brushing teeth after dinner as mentioned in the script?

Brushing teeth after dinner serves as a powerful signal that eating for the day is finished, which can help divert resources towards repair while sleeping rather than digestion.

Outlines

00:00

🍽️ Changing Stance on Fasting Protocols

The speaker discusses the evolution of their views on fasting and meal skipping in the context of longevity. They highlight the influence of Dr. Peter Attia and Dr. Ronda Patrick, who have also revised their positions on fasting. The initial excitement for intermittent fasting stemmed from rodent studies that showed benefits such as weight loss, improved blood sugar control, and increased lifespan, even when calorie intake was the same as the control group. The speaker emphasizes the importance of understanding the human clinical trials on fasting, which have led to a shift in their approach. They point out that autophagy, a cellular process that clears out old damaged components, was observed in rodents during fasting but that human studies have not conclusively shown the same benefits. The speaker also raises concerns about the methodological flaws in some studies, such as calorie intake not being properly controlled, which could skew the results. They conclude by suggesting that the benefits of time-restricted feeding may be due to calorie restriction rather than the fasting itself.

05:01

🥤 Balancing Caloric Restriction with Protein Intake

The speaker advises against multi-day fasts due to potential muscle loss and a lack of evidence supporting their long-term benefits. They explain that while calorie restriction is beneficial for weight loss and diabetes management, it's crucial to ensure adequate protein intake to support muscle health and recovery from resistance exercise. The speaker suggests incorporating a low-calorie protein shake during fasting periods to maintain protein intake. They share their personal preference for having a large breakfast, medium lunch, and a small early dinner, followed by a 30-minute wait before brushing teeth to signal the end of the eating day. This approach, they believe, helps the body focus on repair during sleep. The speaker also recommends against prolonged fasting, as it can lead to muscle loss, which is a significant concern. They conclude by encouraging viewers to watch a subsequent video that delves deeper into protein intake and its role in health.

Keywords

💡Fasting Protocol

A fasting protocol refers to a specific plan or schedule for abstaining from food for certain periods to achieve health benefits. In the video, the speaker discusses their personal fasting protocol, which involved multi-day fasts, and why they eventually stopped following it due to concerns over muscle loss.

💡Meal Skipping

Meal skipping is the practice of intentionally not eating during certain times of the day, often as part of an intermittent fasting regimen. The video addresses the shift in opinion regarding meal skipping, discussing its potential benefits and drawbacks, especially in the context of human research.

💡Autophagy

Autophagy is a cellular process where cells 'self-digest' by breaking down and removing old or damaged components to maintain health. The video mentions autophagy as a potential benefit of fasting, as it was observed in rodent studies where time-restricted feeding led to longer lifespans.

💡Time-Restricted Feeding

Time-restricted feeding is a type of intermittent fasting where eating is confined to a specific window of time within a day. The video discusses how initial excitement for this approach came from rodent studies, but human clinical trials have not shown the same benefits when calorie intake is matched.

💡Calorie Restriction

Calorie restriction involves reducing the total number of calories consumed, which can lead to weight loss and other health benefits. The video suggests that the benefits seen in time-restricted feeding studies may actually be due to calorie restriction rather than the fasting itself.

💡Protein Intake

Protein intake is crucial for muscle building and repair. The video highlights the importance of adequate protein consumption, especially during fasting periods, to prevent muscle loss and to support the benefits of resistance exercise.

💡Multi-Day Fasts

Multi-day fasts involve abstaining from food for more than 24 hours continuously. The speaker used to practice this but discontinued it due to concerns about long-term benefits and muscle loss, as humans metabolize food differently than rodents.

💡Human Clinical Trials

Human clinical trials are scientific studies conducted on human subjects to evaluate the safety and efficacy of medical interventions. The video references these trials as a source of evidence that has influenced the speaker's and other experts' views on fasting.

💡Muscle Loss

Muscle loss refers to the decrease in muscle mass, which can occur during prolonged fasting due to the body breaking down muscle for energy. The video discusses muscle loss as a significant concern that led the speaker to stop their fasting protocol.

💡Intermittent Fasting

Intermittent fasting is an eating pattern where individuals cycle between periods of fasting and eating. The video explores the popularity and potential benefits of intermittent fasting, contrasting it with the realities of human research.

💡Longevity

Longevity refers to the state of living a long, healthy life. The video discusses how fasting practices, particularly those based on rodent studies, were initially thought to promote longevity in humans as well.

Highlights

Dr. Peter Attia and Dr. Ronda Patrick have changed their stance on fasting protocols.

Initial excitement for intermittent fasting came from rodent studies showing benefits like weight loss and increased lifespan.

Autophagy, the cell clearance process, was observed in rodents during fasting, suggesting potential benefits for humans.

A 2020 meta-analysis suggested time-restricted feeding might offer greater weight loss and blood sugar control.

Most human studies on time-restricted feeding have a flaw: the fasting groups tend to consume fewer calories.

A 2012 Cochrane meta-analysis found no difference in weight loss or blood sugar levels when calorie intake was matched.

A 2019 study suggested alternate day fasting might reduce fasting insulin and insulin resistance more than calorie restriction.

The benefits of time-restricted feeding appear to be due to calorie restriction rather than the fasting itself.

Multi-day fasts were thought to powerfully activate autophagy, but there's no good evidence for long-term benefits in humans.

Muscle loss is a significant concern with prolonged fasting, which can outweigh potential benefits.

Time-restricted feeding is beneficial for weight loss and diabetes management, but it's essential to ensure adequate protein intake.

A low-calorie protein shake is recommended during the fasting period to maintain muscle mass.

The speaker personally prefers a large breakfast, medium lunch, and a small early dinner for optimal health.

Multi-day fasts are discouraged due to their impact on muscle stores.

Protein intake is crucial for muscle maintenance and overall health.

The speaker encourages patients to consider time-restricted feeding for weight loss but to be mindful of protein intake.

The speaker shares a personal strategy of having a large breakfast and brushing teeth after dinner to signal the end of eating for the day.

The speaker suggests measuring heart rate overnight to compare the effects of different meal timings on sleep and energy levels.

Transcripts

why did I stop my fasting protocol one

of the biggest things I've changed my

mind on over the past few few years is

um my stance on meal skipping why has

Peter AA and Ronda Patrick who are both

famous doctors in the longevity space

changed their position on fasting and

how should we approach fasting based on

the latest human research to optimize

our health we need to get this right

because if we don't it can take years

off our lifespan this topic can be

confusing so in this video I'll be

breaking it down in simple terms giving

you the pros and cons of meal skipping

so that you know what to look out for

and I'll give you a clear plan on how to

approach fasting in case you decide it's

worth it for you now you've probably

heard great things about intermittent

fasting so what's caused the shift in Dr

a and Dr Patrick's approach well the

initial excitement for intermittent

fasting it came from studies in rodents

which reported that time-restricted

feeding or eating within a small window

in the day reduced body weight improved

blood sugar control lowers insulin

levels and increases lifespan and here

is the critical point even when food

intake is matched to the control group

so we know from previous rodent studies

that restricting calories extends rodent

lifespan but here in the time restricted

feeding studies even when both groups of

rodents were eating the same amount of

food the rodents who ate the food within

that smaller time frame in the day were

living longer that Leed to an explosion

in popularity of time-restricted feeding

where even if you don't need to lose

weight it was hoped that if humans also

ate with within that smaller time frame

in the day we too could live longer and

healthier so how was it thought that

time-restricted feeding could offer

these benefits well when rodents were

fasting for a period of time during the

day scientists took biopsies and they

saw that a process called autophagy was

occurring in the cells of these mice so

autophagy is the cell clearance process

where old damaged components are flushed

away and then new components can be

built it sounds wonderful but we are not

rodents what do the human clinical

trials show and as more research came

through that led to Dr Peter AA and Dr

Ronda Patrick to shift their position at

first the research and humans looked

promising for example a 2020 meta

analysis of the human studies suggested

that time-restricted feeding offered

greater weight loss and reductions in

blood sugar levels compared to other

diets where people could eat whenever

they wanted so it all sounds wonderful

but when we dig deeper we find a big

problem most of the studies that were

done on time-restricted feeding have a

fatal flaw the time-restricted feeding

groups they ate less calories compared

to the control group now this isn't the

problem that led Dr AA and Dr Patrick to

change their position that's coming soon

but it's important that we finish off

this thread remember it was hoped that

time-restricted feeding would offer

benefits Beyond simply restricting

calories that's what the rodent study

suggested but when the Cochran

organization performed a metaanalysis in

20121 where they combined all of the

relevant clinical studies together they

found that the trials that matched the

calorie IND intake between both groups

there were no differences in weight loss

or blood sugar levels even studies that

aimed to calorie match the diet groups

struggled take for example this 2019

study which concluded that alternate day

fasting May produce greater reductions

in fasting insulin and insulin

resistance versus calorie restriction

but when you actually look at the data

and explore how many calories both

groups ate the fasting group still ate

less calories compared to the calorie

restriction group so it was the lower

calorie intake that offered those

benefits it didn't seem to have anything

to do with the fasting itself and it's

the same for fatty liver there appear to

be no further benefits from

time-restricted feeding Beyond calorie

restriction and to put another nail in

the coffin a new time-restricted feeding

study was recently published both groups

ate the same amount of calories but one

group ate within a 10hour window and ate

80% of the food before 1: p.m. while the

other group ate an a usual eating

pattern and had over 50% of their food

after 5 p.m overall there were no

differences in weight loss or blood

sugar levels between the two groups

suggesting that any effect that

time-restricted feeding had on weight is

due to reductions in calorie intake but

isn't restricting calories a good thing

should we use time-restricted feeding to

reduce our food intake yes but here is

where the confusion comes in and this is

why Dr AA Dr Patrick and my previous

fasting videos tried to add Nuance to

this topic controlling calorie intake is

great but we need to be mindful about

protein to maximize the benefits of

resistance exercise and to support

muscle building we want 1.6 g of protein

intake per kilogram of lean body weight

per day so if someone is completely

skipping meals it can be quite difficult

to reach those protein targets for

example often when people practice

time-restricted feeding they skip

breakfast and only eat in the afternoon

and evening that can be great for

restricting calories but not so great

for protein intake instead if someone

wants to have their main meals in the

afternoon and evening to restrict their

overall calorie intake one option would

be to include a low calorie protein

shake in the morning we don't need to

worry about so-called breaking a fast

because we know it's not the fasting

itself that offers the benefits it's the

overall reduction in calorie intake but

what if we take fasting a step further

and perform multi-day fasts in theory

fasting for multiple days in a row

should powerfully activate autophagy and

provide the benefits that we see in the

rodent studies this is actually the

strategy that I used to do about 3 to 4

years ago where every 3 months I would

do a water fast for 7 days now what's

the justification for this well a rat

hour is very different to a human hour

rats have a metabolic rate of roughly

6.4 times that of humans so a rat

fasting for 16 hours is roughly the

equivalent of a human fasting for 4 days

now this is a very crude method but it

likely explains why humans don't appear

to get any additional benefit from time

restricted feeding Beyond calorie restri

restriction whereas rats do especially

when you consider that in humans our

liver stores energy in the form of

glycogen and it can take up to 48 hours

to burn through those glycogen stores

before autophagy really kicks in now I

want to be clear that this is

speculation and it's based on

mechanistic reasoning but it's the

justification provided for multi-day

fasts but I stopped doing these

prolonged fasts because of two reasons

the first is that there's no good human

evidence that this is beneficial in the

long term or the that autophagy is being

activated but the second and probably

more important reason is muscle loss so

every day we break down muscle and if we

don't rebuild that lost muscle we're in

a net loss and we lose strength any

potential benefit I was receiving from

these prolonged fasts they were vastly

outweighed by the negative impact on my

muscle stores similar to what happened

to Dr AA you may ask the question why

did I stop my fasting protocol it's very

difficult to gain back the lean muscle

you keep losing so let's try now and

pull everything together there's no

benefit from time-restricted feeding

Beyond calorie restriction that's what

the human clinical research suggests to

us today calorie restriction is great

for weight loss and to treat diabetes so

in my clinic I frequently advise my

patients who want to lose weight or to

reduce their blood sugar levels to

consider time-restricted feeding but I

encourage them to also use a low calorie

protein shake during the part of the day

where they're fasting this is to make

sure that they're getting enough protein

to look after their muscles I advise

this because it's not that something

magical is happening to the body during

these skipped meals or that we're

activating autophagy it's the calorie

restriction that's doing the trick some

patients want to eat their meals in the

afternoon and which case I advise that

they have a low calorie protein shake in

the morning others want to eat their

meals in the morning in which case

they'll have that protein shake in the

afternoon and evening for me personally

I feel best when I have a large

breakfast and medium lunch and a small

early dinner after dinner I wait 30

minutes and then I brush my teeth that's

a powerful signal that I've finished

eating for the day and by using the

strategy I make sure that when I'm

sleeping my body is diverting resources

to repair rather than digestion it's

actually quite an interesting experiment

to run if you have a smartwatch measure

your heart rate overnight and compare

what happens when you have a large late

dinner compared to an early light dinner

your heart rate will be much lower if

you have an early light dinner and the

vast majority of people wake up with a

lot more energy finally I advise my

patients against multi-day fasts due to

the impact on their muscle stores muscle

is far too important to have it waste

away and I've spoken a lot about protein

during this video but I've only scratch

the surface so I highly recommend that

you check out this next video here where

I go into detail about protein intake

and the best strategies to optimize

protein intake for our health and a

massive thank you to all of the patreons

supporting the channel