Intermittent Fasting’s Darkest Secret

Summary

Intermittent fasting has gained popularity for weight loss and health, but research reveals it works mainly through calorie restriction, not additional benefits. While animal studies show promise, human studies find similar results to other calorie-restricted diets. There are two fixable issues with intermittent fasting - getting adequate protein intake, and proper meal timing. Overall it can help some people lose weight, but does not provide special benefits over other diets. More research on prolonged fasts is still needed regarding muscle loss.

Takeaways

• 😀 Intermittent fasting can help with weight loss and diabetes treatment, but the benefits come from calorie restriction, not something unique about fasting itself.
• 😞 For healthy people who don't need to lose weight, there are no clear additional benefits from intermittent fasting.
• 👊 For weight loss and diabetes treatment, intermittent fasting works due to calorie reduction.
• 🍴 Protein intake and meal timing are key issues with intermittent fasting that need to be addressed.
• ⌛️ Humans don't fast long enough to activate autophagy like mice do in short-term fasts.
• ⏰ Early time-restricted feeding (eating breakfast, fasting at night) may be optimal intermittent fasting pattern.
• 🥣 Eating breakfast is important; the biggest meal should be earlier in the day, not at night.
• 💪 Prioritize protein intake (1.6 g per kg lean body weight) when fasting to protect muscle.
• 🤝 Prolonged fasting has risks - more research needed to confirm potential benefits outweigh them.
• 😊 For some people, intermittent fasting is an effective weight loss tool, so long as protein and meals are addressed.

Q & A

What is the dark secret about intermittent fasting?

The dark secret is that in humans, intermittent fasting works through calorie restriction alone. There is no evidence that something magical is happening beyond calorie restriction.

Why did intermittent fasting become popular initially?

It became popular due to studies in rodents showing benefits like weight loss, improved blood sugar control, and lowered insulin levels even when the intermittent fasting group ate the same calories as the control group.

What are the two main problems with intermittent fasting?

The two main problems are: 1) Not getting enough protein intake leading to muscle loss 2) Having a large meal late at night which can worsen blood sugar control.

How can the protein intake problem be solved?

The protein intake problem can be solved by prioritizing protein in the diet and adding a protein shake if needed to reach the target intake of 1.6g per kg of body weight.

What should the meal timing be for intermittent fasting?

Most calories should be consumed earlier in the day. A good rule of thumb is to eat breakfast like a king, lunch like a prince, and dinner like a pauper to avoid large nighttime meals.

Why don't humans see the same fasting benefits as rodents?

A 16 hour fast for a mouse is equivalent to a 4-5 day fast for a human. So intermittent fasting of 16-24 hours is unlikely to meaningfully activate autophagy in humans like it does in mice.

Is intermittent fasting more effective for weight loss compared to other diets?

No, research shows intermittent fasting is not more effective for weight loss compared to other calorie restriction diets when calories are matched.

Does intermittent fasting lower hunger?

For most people, no. Some individuals may experience lower hunger but generally fasting does not lower overall hunger levels based on clinical studies.

Are there benefits to prolonged fasting?

There are concerns about muscle loss with prolonged fasts. More research is needed to determine if any potential benefits outweigh these known risks in humans.

Who may benefit from intermittent fasting?

It can be an effective strategy for some people to lose weight and treat conditions like diabetes. But otherwise healthy people are unlikely to see additional benefits beyond calorie restriction.

Outlines

00:00

🤔 The dark secret about how intermittent fasting works in humans

This paragraph explains that while intermittent fasting provided various health benefits in rodent studies, human clinical research shows that most of the benefits come from overall calorie restriction rather than effects unique to intermittent fasting. It states that intermittent fasting helps with weight loss and diabetes by reducing calorie intake but does not provide additional metabolic advantages.

05:02

⏰ Why intermittent fasting differs in mice and humans

This paragraph provides reasons why intermittent fasting works differently in mice versus humans. It states that a 16 hour fast for a mouse is equivalent to a 4-5 day fast for a human. So the timeframes typically used for intermittent fasting in humans are unlikely to significantly activate autophagy or provide the same effects seen in rodent studies.

Keywords

💡intermittent fasting

Intermittent fasting refers to an eating pattern that cycles between periods of fasting and eating. It is a popular weight loss strategy that has gained significant interest. The video discusses different types of intermittent fasting such as alternate day fasting and time-restricted feeding. It is one of the main topics explored in depth throughout the video script.

💡time-restricted feeding

A form of intermittent fasting that restricts eating to a certain number of hours per day, usually 8 hours for eating and 16 hours for fasting. The video script reviews research on the benefits of time-restricted feeding, concluding that most of the weight loss benefits come from overall calorie restriction rather than any magical effects unique to intermittent fasting.

💡calorie restriction

Reducing overall calorie intake, which is shown by research reviewed in the video script to be the primary reason behind weight loss from intermittent fasting rather than any special effects of fasting itself. The video emphasizes that intermittent fasting works mainly by getting people to eat fewer calories compared to non-fasting approaches.

💡autophagy

A cellular housekeeping process of clearing out damaged cell components. It was hypothesized to be one of the key mechanisms behind the health benefits of intermittent fasting, based on animal research. But human trials have not found fasting to activate autophagy meaningfully or provide added benefits beyond just calorie restriction, as discussed in the video.

💡protein intake

Getting adequate protein while intermittent fasting can be challenging for some people according to the video, which can lead to loss of muscle mass. It recommends prioritizing protein intake within the eating window by using strategies like protein supplementation if needed.

💡meal timing

The video advises avoiding large meals late at night when intermittent fasting, as this can spike blood sugar. It suggests early time-restricted feeding where calories are consumed earlier in the day within the restricted eating window instead.

💡adherence

How well people can stick to an intermittent fasting regimen over long periods. The video says clinical trials show adherence tends to be suboptimal, with most struggling to maintain fasting protocols - something important to keep in mind when considering intermittent fasting.

💡prolonged fasting

Fasting for extended periods of time, beyond the typical 16-24 hour windows used in intermittent fasting protocols like time-restricted feeding. The video says there are concerns about muscle loss and other risks with prolonged fasting.

💡weight loss

The video analyzes multiple research studies on using intermittent fasting for weight loss. It concludes intermittent fasting does not appear to confer any special weight loss advantage compared to other calorie-restricted diets when calories are matched.

💡diabetes

Intermittent fasting is sometimes promoted to help treat diabetes by lowering blood sugar. But human trials covered in the video show mixed results, with benefits again arising largely from calorie restriction rather than any unique effects of fasting itself.

Highlights

Intermittent fasting comes in many forms but the popular ones are time-restricted feeding and alternate day fasting.

Time-restricted feeding in rodents reduced body weight and improved blood sugar control even when food intake was matched.

Human research shows time-restricted feeding promotes weight loss likely because fewer calories are consumed.

Intermittent fasting is not more effective for weight loss or reducing blood sugar compared to other calorie restriction diets.

Modern intermittent fasting protocols seem to be largely a rebranding of classic calorie restriction methods.

Mice studies don't translate to humans because a 16 hour mouse fast is equivalent to a 4-5 day human fast.

Higher protein intakes associate with lower mortality, but intermittent fasting makes it hard to reach protein targets.

Total protein intake matters more than meal frequency for muscle mass maintenance.

Most benefits of intermittent fasting come from calorie restriction. There's no evidence of unique metabolic effects.

Have an early, light dinner and brush teeth to signal the end of eating for powerful health benefits.

Prioritize protein intake when intermittent fasting to avoid muscle loss.

Take most calories earlier in the day - breakfast like a king, lunch like a prince, dinner like a pauper.

Consider supplements for micronutrient intake but remember they may not be right for everyone.

Check the linked video for more details on the recent landmark protein intake study.

Thank patrons supporting the channel for making videos like this possible.

Transcripts

there's a dark secret about intimate and

fasting that you need to know about

because if you get this wrong you can

significantly worsen your health and

increase your chance of developing

diabetes this is a nuanced topic so I

highly recommend that you watch this

video Until the End where I pull

everything together and summarize the

latest intermittent fasting guidelines

intermittent fasting comes in many

different forms but the popular ones are

time-restricted feeding where you only

eat within a certain window in the day

typically you eat within 8 hours and

fast for the other 16 other popular

forms are alternate day fasting and one

meal a day and the excitement for

intermittent fasting came from studies

in rodents which reported that

time-restricted feeding reduced body

weight improved blood sugar control and

lowered insulin levels and critically

this happened even when food intake was

matched to the control group so both

groups of mice ate the same amount of

calories but the time-restricted feeding

group seemed to get all of these

additional benefits which led to an

explosion in popularity for intermittent

fasting where even if you didn't need to

lose weight some longevity scientists

were advocating for intimate and fasting

as a strategy to extend lifespan and the

presumed mechanism for these possible

benefits was a process called autophagy

or the cell clearance process so as we

age we collect old damaged components

within our cells and autophagy is the

process where we clear those old

components away so that we can rebuild

new ones and autophagy is strongly

activated by starvation but we are not

mice what does the human clinical re

search show and that's where the dark

secret about intimat and fasting is

uncovered starting with a 2020

metaanalysis that pulled all of the

relevant clinical trials together it

concludes that time-restricted feeding

achieved Superior effects in promoting

weight loss and reducing blood sugar

levels compared to approaches with

unrestricted time meal consumption that

all sounds wonderful but then you dig a

bit deeper and bear with me because it's

quite the rabbit hole the

time-restricted feeding groups ate less

calories compared to the control group

so when you analyze Iz the research it

appears that time-restricted feeding is

effective for weight loss probably

because fewer calories are consumed and

that makes sense if you've made a

conscious decision not to eat during

certain parts of the day generally

you're going to consume less calories

overall which begs the question what

benefits does intimat and fasting

provide Beyond calorie restriction well

according to a Cochran review published

in 2021 it appears that intimate and

fasting is not more effective for weight

loss compared to other energy

restriction diets the analysis also

found that intermittent fasting is not

more effective to reduce blood sugar

levels when compared to other

restriction diets take for example this

2019 randomized control trial that tried

to make sure that both groups were

eating the same amounts of calories but

one group was practicing alternate day

fasting the study concluded that

alternate day fasting May provide

greater reductions in fasting insulin

versus calorie restriction which again

sounds great but then you have a closer

look during the study both the alternate

day fasting groups groups and the

calorie restriction groups reduced their

net calorie intake by 25% per day the

calorie restriction group ate

1,761 calories per day whereas the

alternate day fasting groups on the day

that they were fasting they ate

1,175 calories and on their feast day

they ate

1,763 so overall the alternate day

fasting group still ate less calories

compared to the calorie restriction

group so if one group is eating less

calories compared to the other

that is why they see benefits what about

potential benefits for Hunger levels

some people who practice intimate and

fasting say that their overall hunger

levels decrease and if that's you great

but in the clinical studies generally

most people struggle to stick with

fasting the adherence is suboptimal

there's always going to be exceptions to

the rule but generally speaking fasting

does not overall lower your hunger

levels what about benefits for fatty

liver well in a massive 2023 randomized

control trial time restricted feeding

did not produce any additional benefits

for reducing body fat or liver fat

compared to daily calorie restriction

and other meta analyses that pull all of

the relevant clinical studies together

keep coming to the same conclusion

intimate and fasting is not associated

with greater or lesser weight loss than

non-intermittent fasting diets and taken

from Professor Matt caline's review it

appears that modern intermittent fasting

Protocols are largely a rebranding of

classic calorie restriction methods

here's the dark secret about

intermittent fasting people who use

intermittent fasting to help lose weight

and treat their diabetes they're getting

those benefits simply from calorie

restriction alone from the human

research that we've got there's nothing

magical about intimat and fasting so for

otherwise healthy people who don't need

to lose weight or treat their diabetes

there doesn't appear to be any benefits

from practicing intimat and fasting but

there are two Sinister issues with

intermittent fasting that I'll cover

shortly and both can be solved but first

why do humans not get additional

benefits from intermittent fasting like

mice do Beyond calorie restriction well

it's important to remember that a mouse

hour is not the same as a human hour so

broadly speaking if a mouse fasts for 16

hours that's roughly the equivalent of a

human fasting for about 4 to 5 days and

the human liver has energy reserves that

last about 48 hours so it's highly

unlikely that autophagy is going to be

meaningfully activated if you're fasting

for between 16 to 24 hours longer fast

may have different effects but then you

need to worry about losing muscle mass

and that brings me onto the first of two

issues with intermittent fasting and

that is protein intake and muscle mass a

2020 study published in the British

medical journal found that higher

protein intakes are associated with

lower all cause death rates and ideally

we want to be reaching 1.6 g of protein

intake per kilogram of lean body weight

per day but if you're fasting it can be

incredibly difficult to reach those

protein targets which which is why

intermittent fasting can represent a

suboptimal dietary approach to remodel

sceletal muscle now the protein research

recently had a massive update which I

covered in a video here it used to be

thought that protein intakes should

ideally be evenly distributed throughout

the day where you have a protein meal

every 3 to 4 hours but a landmark study

published this year 2024 found that

eating a single large amount of protein

is likely just as effective as splitting

that protein intake through multiple

meals

this may explain why time-restricted

feeding patterns do not seem to

compromise muscle mass maintenance

instead when it comes to protein intake

and muscle mass it's the total protein

intake through the day that seems to

really matter rather than the frequency

of the protein meals so if you're using

intimate and fasting to restrict

calories to lose weight and treat

diabetes make sure that you're

prioritizing your protein intake and if

you're struggling to reach your protein

targets you can consider adding a

protein shake this is a fixable problem

with short intermittent fasting

prolonged fasts though that's a

different story there's a significant

concern that we lose muscle mass with

prolonged fasts and we don't have the

long-term human research to know whether

any potential benefits from these

prolonged fasts outweigh the known risks

the second fixable problem is meal

timing most people who practice

time-restricted feeding skip breakfast

and have a large meal at the end of the

day that's a bad idea we have multiple

studies showing that if you have a large

meal at the end of the day that worsens

blood sugar levels and impaires Insulin

responses and I'm going to show some of

those studies on screen now having

breakfast is important and that's why

the current intimate and fasting trials

are examining early time-restricted

feeding as in making sure you're getting

your calories in the morning and fasting

in the evening so let's pull it all

together intimate and fasting can be a

great way for some people to lose weight

and treat their diabetes and if that's

you brilliant but the dark secret is

that it works via calorie restriction in

humans there's no evidence that

something magical is happening Beyond

calorie restriction and there are two

important but fixable problems the first

one is protein most people who practice

intimate and fasting aren't getting

enough protein intake but so long as you

know that you can prioritize your

protein intake and make sure that you're

reaching that 1.6 g of protein intake

per kilogram of body weight per day the

second fixable problem is meal timing

make sure you're getting most of your

calories in the morning compared to the

evening but here's the most important

Point most people to significantly

improve their health should aim to have

a light early dinner and then

immediately brush your teeth that's a

powerful signal that you've finished

eating for the day you want to cut out

the late night eating a general rule of

thumb is to eat breakfast like a king

lunch like a prince and dinner like a

poer and for me personally to make sure

that I'm reaching my micronutrient

intakes I take microv vitamin but please

remember that just because I take a

supplement does not in any way mean that

you should as well in this video I've

talked a lot about protein intake so

make sure to check out this next video

here that goes through that new protein

study in detail and a massive thank you

to all of the patrons supporting the

channel