0:02 Daily 16-day fasting feels productive
0:04 until it suddenly stops working. And
0:06 that's not really willpower. It's
0:09 biology. When you compare 12-hour fasts,
0:12 24-hour fasts, 36-hour fasts, 72-hour
0:15 fasts, you can actually see where 168
0:17 goes wrong and why it eventually slows
0:18 down the very metabolism that you're
0:20 really trying to speed up. I actually
0:22 had a moment years ago where I was doing
0:25 168 just about every single day. I felt
0:27 really sharp. I actually felt really
0:28 light. I mean, all the feelings that you
0:30 know of, like it feels really good. And
0:32 then one morning, I kind of woke up and
0:34 I just felt flat. And it was like the
0:36 first day I realized, wait a minute, my
0:39 energy was really low. My strength had
0:41 dipped. And and I remember thinking
0:43 like, how am I eating less and somehow
0:45 burning less? Like it feels like my
0:47 engine's just not running hot. And that
0:48 moment sent me down this scientific
0:51 rabbit hole of trying to understand the
0:52 frequency of fasting, not just the
0:55 duration. And once you understand this
0:57 and you see it, you can't really unsee
0:59 it because fasting is a lot more
1:01 effective and honestly just way more
1:03 reliable. It's more dependable. It's
1:05 sustainable. You can use it as an
1:07 accurate tool. And that's what I do now.
1:09 And it's so effective. So, so here's
1:10 where we're going with all of this
1:12 today. And I want to keep it super clear
1:13 and really not get too far in the weeds
1:15 of the science. But first, we're going
1:17 to look at what fasting actually does to
1:18 metabolic rate because there's a sweet
1:21 spot where the metabolism increases, but
1:22 then there's a point where it actually
1:25 noses. And then secondly, we're going to
1:27 look at glucose tolerance because the
1:30 goal isn't to burn fat for one day. The
1:31 goal is to become metabolically flexible
1:33 long term so you're not having to fast
1:35 every day. Then third, we're going to
1:37 put it all together so you know how
1:38 often you should fast without really
1:40 slowing your metabolic rate and also how
1:41 to do it without wrecking glucose
1:43 control because that can actually
1:44 happen. So, let's go ahead and let's
1:45 just jump into section one, which is
1:47 going to be all about the metabolism
1:48 piece with some cool studies there. And
1:50 I want to talk about one study in
1:51 particular that was in the British
1:53 Journal of Nutrition. And it might be
1:55 one of the most misunderstood fasting
1:56 papers that's out there. And it's good
1:58 that I'm covering it because it was a
2:00 big one. They looked at 12-hour fasts,
2:02 they looked at 36-hour fasts, and they
2:04 looked at 72-hour fasts. Now,
2:06 intuitively, you'd think that the longer
2:09 you go, the more your metabolism ramps
2:11 up because fasting does increase
2:13 epinephrine and norepinephrine and
2:15 adrenaline. So, things do actually ramp
2:17 up as you go into a fast. It's partially
2:19 true, but only up to a point because
2:21 here's what they found. After 12 hours,
2:24 the metabolic rate barely changed. It
2:25 was really just kind of neutral. I mean,
2:27 there was more fat oxidation for sure,
2:29 but metabolic rate wasn't changing. What
2:31 they found is that after about like 24
2:33 to 36 hours, metabolic rate was
2:36 increasing. Your body really starts
2:38 ramping up norepinephrine. You get a
2:40 major increase in circulating fatty
2:42 acids in conjunction with the
2:43 adrenaline, which just puts you into
2:45 like fat burning mode. You really
2:48 upshift into that fat burning gear. Then
2:50 after about 72 hours, metabolic rate
2:52 doesn't go any higher than the 36-hour
2:54 mark. So what's happening is that
2:56 short-term fasting increases the
2:58 catakolamines. So we got adrenaline,
3:00 norepinephrine, and that keeps energy
3:03 expenditure from dropping. It actually
3:05 protects you. But once you extend the
3:09 fast beyond 36 hours, but this also ties
3:12 in with fasting too frequently, the body
3:15 recognizes a consistency pattern. And it
3:17 starts to say, "Oh, oh, oh, we're
3:20 starving. We should conserve energy." So
3:22 what this is telling us is that a
3:25 well-timed long fast speeds your
3:28 metabolism up. But doing it too often,
3:30 even with shorter fasts, or stacking
3:33 calorie restriction on top of it on the
3:35 days you're not fasting, will slow it
3:37 down. So, that brings me to the second
3:39 point in this video because short-term
3:43 fasting is just one side of the coin.
3:44 Uh, we need to kind of talk about how
3:46 this all plays together, right? Because
3:47 the other side is what happens when
3:49 you're chronically undereating without
3:52 realizing it. Been my problem for like a
3:54 half a decade, right? you get hooked on
3:56 feeling good with the lower calories.
3:58 And there's a really good study that was
4:00 in the American Journal of Clinical
4:02 Nutrition, and it looked at what
4:04 happened when people overeat for one
4:06 week, but then went into a 50% caloric
4:08 deficit for 3 weeks, then reed for two.
4:11 So overeat one week, then caloric
4:14 deficit for 3 weeks, and then refeed for
4:17 two. 3 weeks of what most people would
4:19 consider just dieting a little too hard.
4:21 All right. So, in that short window,
4:24 their resting metabolic rate tanked by
4:29 266 calories per day. In 3 weeks, their
4:33 daily metabolic rate went down 266
4:35 calories per day. Almost half of that
4:37 was adaptive thermogenesis, meaning that
4:40 the body voluntarily slowed itself down
4:43 to survive. They lost 5% of their muscle
4:46 mass in 3 weeks, which further dropped
4:48 their metabolism. So, in other words, if
4:51 your fasting routine turns into chronic
4:53 calorie restriction, especially with
4:55 something like daily 168, you can
4:57 unintentionally shut the system down
4:59 that you're trying to speed up. And this
5:01 is exactly why people feel great for the
5:03 first couple weeks of fasting and then
5:05 they stall or even a couple of months or
5:06 even it just becomes a lifestyle and
5:08 just nothing happens. They don't really
5:09 change it. They just feel good, but
5:11 their body doesn't change. It's wild how
5:13 fasting can happen, especially if you
5:14 don't have a whole lot of fat on you,
5:17 right? So within about 2 to 3 weeks of
5:18 continuous reduction in calories, your
5:21 metabolism begins to downshift. It's not
5:24 months, it's not years, it's 14 to 21
5:27 days. Here's the kicker. That same
5:29 slowdown does not happen with
5:32 infrequent, strategically placed
5:36 moderate length to longer fasts. Why?
5:37 Well, because the body interprets those
5:40 as acute temporary stressors, not
5:42 starvation. You also want your body to
5:44 be able to recover and build off of
5:47 those fasts. What I mean by that is you
5:49 have all kinds of cellular changes and
5:51 repair that happen during a fast. You
5:54 have reorganization, reallocation and
5:56 autophagy and then you need to actually
5:59 rebuild. It takes protein. It takes
6:02 calories to rebuild. So all the mphagy
6:03 you're going through where the
6:05 mitochondria are going through their own
6:08 respective autophagy to consolidate and
6:10 get stronger, if you don't have periods
6:12 of rebuilding,
6:15 that doesn't do you any good. So fasting
6:17 is a stressor on the mitochondria.
6:19 Calorie restriction is a stressor on the
6:22 mitochondria. Then you need to be able
6:25 to repair from that stressor. The
6:27 stressor is the signal and then you need
6:29 the repair. So you don't just
6:31 consolidate your mitochondria or
6:34 consolidate cells and then continue to
6:37 fast and have that happily continue. You
6:40 consolidate and then you power them up.
6:43 Right? So it's like you want to take all
6:45 the junked vehicles in your junkyard,
6:47 consolidate all the parts to make one
6:49 supercar, but then you got to put fuel
6:51 in that supercar, otherwise it's still
6:53 just eh sitting there, right? This is
6:55 where that product timeline can come
6:57 into play. I think this is cool science
7:00 with this because this is a compound
7:03 uriththnan A that induces mitochondrial
7:05 autophagy mphagy. It's been published in
7:07 a lot of papers been published in JAMMA
7:09 all kinds of different research journals
7:12 because it induces autophagy or of the
7:14 mitochondria. It's called mphagy. So you
7:16 take that regularly but you can take
7:18 that even when you're not fasting and it
7:20 kind of continues that autophagy effect
7:23 and it helps rebuild those mitochondria.
7:26 So, this is one of the most foundational
7:28 like longevity compounds that's out
7:31 there, but personally, I take it more so
7:33 because I get better recovery and I feel
7:34 like my mitochondria is stronger from
7:36 it. I popped the link down below. That's
7:38 a special discount link, so you can use
7:39 that link down below so you can use
7:42 their capsules. They've got a powder.
7:43 They also have gummies, which taste
7:44 pretty good, too, and they don't have
7:46 sugar in them. So, that link is down
7:48 below. These guys are great. They're a
7:50 Swiss company that really focuses on
7:52 precision, too. So, this stuff is legit.
7:54 Link down below. So, don't crash your
7:55 metabolism. All right, we've talked
7:57 about that. And now that we've covered
7:59 that piece, let's jump into part two of
8:00 this, which is the glucose tolerance
8:02 piece, cuz fat loss is not just about
8:04 what you're burning today. It's about
8:06 what your body is choosing to burn today
8:08 and tomorrow. Okay, the rate limiting
8:10 step here is how well your cells respond
8:12 to insulin. And you probably know this
8:14 by now. Fasting helps with insulin
8:15 dynamics and all this, but if your
8:17 glucose tolerance is dropping, your
8:19 insulin goes up and your fat burning
8:21 shuts off. And that's not good, right?
8:23 That could be a serious problem. And
8:25 there's a really interesting study that
8:27 was in the Journal of Applied Physiology
8:29 that kind of outlined this a little bit
8:31 more. They had subjects fast for either
8:34 13 hours or 72 hours before actually
8:38 eating a test meal. And after the
8:41 72-hour fast, fat oxidation was higher,
8:43 as you'd expect. But glucose tolerance
8:45 got worse. Their blood sugar glucose
8:47 spiked higher, insulin spiked higher,
8:49 and glucose oxidation dropped. And this
8:51 is the body going, I've been running on
8:53 fat for a few days. I'm not switching
8:56 gears very easily over here. Like the
8:57 body likes to kind of find these
8:59 grooves. So researchers think that this
9:01 might be due to elevated growth hormone
9:05 levels, which is good, but it also could
9:07 be elevated free fatty acids that are
9:09 impairing the insulin signaling. Again,
9:12 it has its place, but may not always be
9:15 a good thing. So long fasts burn fat
9:17 like crazy, but if you do them too
9:19 often, you start losing your ability to
9:21 process carbs normally. And you might be
9:22 thinking like, I'm not going to have
9:24 carbs anymore, so who cares? There will
9:26 come a time when you have carbs. So,
9:28 let's be real here. I don't care. Even
9:30 the strongest carnivore people still
9:31 occasionally will have carbs. It just
9:34 happens, right? And are you 99% of the
9:36 population or you 1% of the population?
9:38 Who's going to eat carbs? Right? So,
9:40 even me, I don't eat a lot of carbs, but
9:41 I want my body to be adjusted to them.
9:43 But here's the cool counterpoint because
9:44 there was a study that was in
9:46 endocrinology and this was a mouse study
9:49 but they found that mice doing three
9:51 24-hour fasts per week uh like
9:53 non-consecutive. They did this and the
9:55 glucose tolerance improved dramatically
9:57 if they were doing like these 24-hour
10:00 fasts non-consecutive glucose tolerance
10:02 improved. They got better. So again,
10:05 frequency is everything. How often we do
10:08 them, how long we do them. Shorter fasts
10:10 done intermittently with breaks improve
10:12 insulin sensitivity because you have a
10:14 period of time in between to actually
10:16 mess around with your new insulin
10:17 sensitivity that you just got from
10:20 fasting. Ultra long fasts done too
10:22 frequently actually impair it. I think
10:23 this is where like Peter Ao was like
10:25 what he was getting at when he was
10:26 talking about how he quit fasting. Like
10:28 I think he was just like an all or
10:30 nothing guy and going like full boore
10:32 into fasting and was doing like long
10:34 fasts all the time. Of course that's
10:35 going to be problematic. like no one's
10:37 saying to do that. Anyway, now that
10:38 we've covered the metabolic rate and
10:40 glucose tolerance piece, I want to move
10:42 into the part where we kind of tie it
10:44 all together. How often you should
10:46 actually fast, like what you can do
10:48 personally. And here's the pattern that
10:50 the research paints uh when you kind of
10:51 overlay everything we've talked about.
10:53 If you fast every day, especially with
10:56 168, and you unintentionally undereat,
10:59 you have about 2 to 3 weeks of a window
11:01 before your metabolism begins to slow
11:02 down. And that's why people see amazing
11:05 results for like two, three weeks and
11:06 then the wheels fall off. But when you
11:08 back up and you kind of zoom out, the
11:09 research says something pretty
11:11 empowering. You don't need to fast every
11:15 day to get the benefits. Okay? You might
11:17 not get as strong of fat loss benefits
11:18 right in the beginning, but you're going
11:20 to get them for ever. In fact, not
11:22 fasting every day is what keeps your
11:25 metabolism high. If you do one 36-hour
11:28 fast per week or two non-consecutive
11:31 24-hour fasts or even three separate
11:33 16-hour fasts, you get the
11:35 norepinephrine bump. You increase fat
11:37 oxidation. You improve glucose
11:39 tolerance. You avoid this metabolic
11:42 downshift. Here's the part I really want
11:44 people to hear. Consistency doesn't mean
11:46 every day. We have it programmed that we
11:48 need to grind every day. Like,
11:50 consistency just means it's repeatable.
11:52 It means it's sustainable. It means it's
11:54 something your body can adapt to long
11:56 term without defending itself. The Cell
11:57 Reports Journal data is actually
11:59 fascinating here. They found the longer
12:02 that you can sustain a form of caloric
12:04 restriction across your life, fasting,
12:07 etc., not extreme restriction, just mild
12:09 restriction, the longer you can sustain
12:12 it, the more you will see improvements
12:15 consistently and reliably. You're going
12:16 to see improvements in cellular
12:19 housekeeping, in autophagy, in metabolic
12:21 health markers, in fat loss, but you can
12:23 only sustain it long term if you're not
12:25 constantly shrinking your metabolic
12:27 rate. Fasting works because it is a
12:29 pulse. It is a stressor. It is a
12:32 strategic interruption. Okay? When it
12:34 becomes daily deprivation, the system
12:36 breaks down. So, here's what I would
12:38 suggest. Okay? Based on everything we've
12:40 covered today, use fasting like a
12:43 sprint, not a marathon. Intervals, okay?
12:45 Go hard for a short burst and take a
12:48 break. If you're doing daily 168, you
12:50 got to give yourself a reset every
12:52 couple weeks. Okay? I understand it's a
12:54 lifestyle thing and it works great. You
12:55 have to take a few days off every couple
12:58 weeks. Then if you prefer longer fasts,
13:00 use them sparingly. Do them once a week,
13:03 maybe once every other week, okay? It's
13:05 enough to get the metabolic pop, but not
13:07 enough to really trigger the slowdown if
13:08 you're keeping an eye on it. And also
13:11 keep the protein super high because
13:12 you're breaking down. you need to
13:14 rebuild. Don't be afraid of mTor. Don't
13:17 be afraid of rebuilding. Okay. Let me
13:18 give you three simple takeaways you can
13:21 implement just right now. Okay. Number
13:24 one, if you are doing daily fasting,
13:28 insert a break every 7 to 14 days for
13:31 like 2 to 3 days. Okay. Let your
13:33 metabolism breathe. Just let it breathe.
13:36 Number two, if you like longer fasts,
13:40 try doing one or two 24-hour fasts
13:42 weekly or at least like maybe one
13:46 36-hour fast every 10 days or every two
13:48 weeks. Do not do multiple days in a row.
13:50 Is never a real reason to do that unless
13:52 you have a very specific thing. Number
13:55 three, keep protein high during eating
13:58 windows to preserve muscle. Okay, this
14:01 is super important because protein is
14:04 your absolute like metabolic insurance
14:05 policy. It's making sure you have that
14:07 muscle so that you can have the
14:09 metabolism going forward. And number
14:13 four, pay attention to how you feel day
14:15 to day and week to week. If your energy
14:18 is dropping, that means your calories
14:19 are probably too low the following
14:20 couple of days or the previous couple of
14:22 days. So, if energy drops, if strength
14:25 drops, or if sleep falls off, if it
14:27 feels really weird, you're not sleeping
14:29 well, that is your really early warning
14:30 sign that you're sliding into metabolic
14:32 conservation. At the end of the day,
14:34 it's not about discipline. It's about
14:36 sustainability, rhythm, and consistency.
14:38 When you hit the right rhythm, your
14:40 metabolism doesn't fight you anymore. It
14:42 works with you because that's the way
14:44 it's supposed to be. It's a beautiful
14:46 system that we have from our creator,
14:48 right? like we can work in harmony with
14:49 our environment and that includes our
14:51 food and that matters because fasting is
14:53 often used for one specific reason,
14:55 right? It's to drive autophagy and
14:57 cellular repair and all these other
14:58 things like to clean up and that's
14:59 important because fasting is used for
15:02 all kinds of reasons like whether it's
15:04 spiritual, whether it's cellular cleanup
15:06 or fat loss or just because it feels
15:07 natural, right? I think there's some
15:08 other components of fasting that people
15:10 really like that can activate some of
15:12 these sort of longevity like cleanup
15:14 attributes. In another video, I broke
15:16 down a compound that's derived from an
15:18 actual leaf, believe it or not, that
15:20 activates many of those same repair
15:22 pathways without requiring a lot of
15:25 extended fasts. Or you could couple it
15:27 with some fasting to get an extra
15:28 benefit. It just gives you another tool
15:31 when it comes down to cellular repair on
15:33 the days maybe when fasting isn't the
15:35 right tool or when you want to like
15:36 accelerate a fast a bit more. So, that
15:38 video is right here. I recommend you
15:40 check it out. Please do subscribe and I
