We used to just call it, NOT EATING.

But now it has a name.

Intermittent Fasting

And its all the rage.

Keto is like so 2018, am I right?

Dr. Oz is even on the bandwagon, and we all know he NEVER gets on bandwagons…

This is pretty much sums up how I’ve felt about IF since it first burst onto the scene circa 2010,

“It is a profound and necessary truth that the deep things in science are not found because they are useful; they are found because it was possible to find them.”
― Robert Oppenheimer

Much ado about nothing.

My 2 cents has always been you see improvements in health because YOU LOST WEIGHT and WEIGHT LOSS explains 95% of the health benefits you see from any and all diets.

But maybe there is more to the Intermittent Fasting story so we should start, at the start.

Intermittent Fasting Bursts on the Scene….

Like the Kool-Aid man bursting through the wall,

IF isn’t as new as you may think.

It was a thing in the fitness industry circa 2010ish.

Every internet fitness celeb was on the IF train at some point between 2010 and 2014.

This talk is from 2012, listen to the prediction he makes at 1 minute in.

Regardless, I agree 100% with his point,

“Whether or not you agree with intermittent fasting, it’s important to understand it”

As far as I know, many of the “early adopters” back in the 2010’s  have moved away from IF, and don’t pray at that alter anymore but I don’t really know.

So 5 years came and went and here we are…

IF Strikes Back or Intermittent Fasting, Round 2

Unless you’ve been in a doomsday bunker for the last few months, you probably know that Intermittent Fasting is THE diet program of 2020 for health, wellness, life extension, good looks, wealth, and all the other things we all want.

I think much of IF’s resurgence lately can be tied to Dr. Rhonda Patrick and her appearances on the Joe Rogan and Tim Ferriss podcasts (can we say autophagy), as well as her own podcast, Dr. Jason Fung and his best seller, The Obesity Code and was solidified in late 2019 with the release of this paper in the New England Journal of Medicine,

Effects of Intermittent Fasting on Health, Aging and Disease

Which concluded,

“Preclinical studies and clinical trials have shown that intermittent fasting has broad spectrum benefits for many health conditions such as obesity, diabetes mellitus, cardiovascular disease, cancers and neurologic disorders.”

That’s pretty convincing in favor of IF and like any study with a strongly worded conclusion that promises magic, it was touted all over the fake news. 

And lord knows we NEVER take things too far, read into things too much, make inappropriate, inaccurate and really BS associations and leaps in logic when it comes to health, wellness, exercise, nutrition etc…

Truth is, there are still lots of things we don’t know about intermittent fasting, but we have some good ideas about some things…

What The Hell is Intermittent Fasting Anyway?

Intermittent fasting is a way of time restricted eating.

“Intermittent fasting is a broad term that encompasses a variety of programs that manipulate the timing of eating occasions by utilizing short-term fasts in order to improve body composition and overall health.” –Effects of intermittent fasting on body composition and clinical health markers in humans 

The most common IF protocols are:

• 14:10 (14 hours of fasting, 10 hour eating window)
• 16:8 (16 hours of fasting, 8 hour eating window)
• Whole day fasts (1-2 days per week of fasting with normal consumption (ad libitum) on other days)
• Alternate day fast (alternating fasting and ad libitum days)

While there are a whole host of other IF strategies, these are the most common.

Can I Eat Whatever I Want?

In short, you can, within your eating window.

This doesn’t mean you can or should pound cookies, cakes and pizza within that time.

If you overeat, and you definitely can, and end up in a calorie surplus you WILL gain weight, no matter how long or often you fast.

The general assumption with IF is that you’ll still maintain a healthy diet, just consuming that diet within your eating window.

Yes, this can and probably will allow you some more diet “flexibility” however, because if you do decide to pound Oreos its only for 8 hours a day and not 24.

What’s the Goal(s) of Intermittent Fasting?

IF has several “goals” as I see it.

• Weight Loss, but really if you’re here we’re after body fat loss, or really body composition improvements.
• Metabolic Flexibility (the ability to switch fuel sources)
• Anti-aging and Chronic Disease prevention

This is gonna take a minute, or a few posts, so lets get started.

Weight Loss/ Body Fat Loss

When it comes to losing weight, the laws of thermodynamics are still at play.

Calories still matter.

But does restricting the amount of time you can stuff your pie-hole make a difference?

It seems that Intermittent Fasting is pretty consistently an effective weight loss strategy,

“it appears that intermittent fasting programs are able to reduce body weight and body fat. Alternate-day fasting has been shown to reduce body weight (3%–7%), body fat (3–5.5 kg), total cholesterol (10%–21%), and triglycerides (14%–42%) in normal-weight, overweight, and obese humans. Reductions in LDL and blood pressure and increases in LDL particle size have also been seen in some, but not all, alternate-day fasting studies. Whole-day fasting has also been shown to reduce body weight (3%–9%), body fat, total cholesterol (5%–20%), and triglycerides (17%–50%). However, some studies indicate that neither alternate-day fasting nor whole-day fasting provides greater body composition improvements than isocaloric caloric restriction” – Effects of intermittent fasting on body composition and clinical health markers in humans

Wait?

What?

“greater body composition improvements”

Intermittent Fasting MAY, as in, MIGHT, or, it is a POSSIBILITY, retain more lean mass with IF versus daily calorie restriction,

“it would appear as though a lower proportion of lean mass is lost in response to intermittent CR (90% weight lost as fat, 10% weight loss as fat free mass) when compared to daily CR (75% weight lost as fat, 25% weight loss as fat free mass). Although the reason for this maintenance of lean mass is not clear, these preliminary findings suggest a preferential retention of fat free mass by intermittent restriction regimens when compared to daily restriction protocols.” – Intermittent versus daily calorie restriction: which diet regimen is more effective for weight loss?

But this finding needs to be taken at face value with a high degree of skepticism for now because of the different populations studied and equipment used to measure body fat wasn’t uniform in the trials.

The vast majority of which used BI (bioelectrical impedance) to measure body fat%.

“It is important to note, however, that comparing values for fat mass and fat free mass between studies is difficult as different techniques were employed to assess these parameters. More specifically, the majority of daily CR trials implemented dual‐energy X‐ray absorptiometry (DXA) and magnetic resonance imaging (MRI), while the majority of intermittent CR trials employed bioelectrical impedance analysis. It is well known that DXA and MRI are vastly more accurate techniques for the assessment of fat mass and fat free mass when compared to bioelectrical impedance analysis 33. Thus, the different methods employed could create variability when comparing findings between diets.” – Intermittent versus daily calorie restriction: which diet regimen is more effective for weight loss?

Bioelectrical impedance is ok if ya just need a quick reference and ease of measurement.

But compared to DXA, it blows,

“results indicates that some individuals can have their FFM values overestimated by more than nine kilograms (Equation (2)) and underestimated by more than eight kilograms (Equation (4)), which is an error of 16% and 14% for more and less, respectively, when comparing the average of the FFM values determined by DXA.”- Validity of Bioelectrical Impedance Analysis to Estimation Fat-Free Mass in the Army Cadets

And BI is even worse vs MRI.

I’m highly skeptical of this, lean mass retention effect, from IF but wouldn’t rule it out completely in all scenerios.

Personally, I think there is a strong possibility that it may only be seen in obese and overweight or sedentary populations and does not occur in leaner, more heavily muscled or highly active populations.

And is most likely HIGHLY dependent on both the length of fasting and the degree of refeeding.

Why IF Might Retain More Lean Mass

If you go on a calorie restricted diet you’re probably going to lose some muscle mass.

There are 3 things that can help maintain muscle mass when losing weight.

1. Resistance training
2. High protein intakes
3. Small caloric deficits = slow rates of weight loss.

But even under the best conditions, you’re going to lose some muscle mass if you restrict calories and lose weight.

How We Lose Muscle Mass a Quick And Dirty Version:

Muscle Protein Synthesis vs. Muscle Protein Breakdown

Muscles are in a constant flux of building or anabolism (MPS) and breaking down or catabolism (MPB).

When MPS is greater than MPB you gain muscle.

MPB is greater than MPS you lose muscle.

The rate of MPB = MPS, you maintain muscle.

“Muscle proteins are constantly turning over, i.e., broken down (or degraded) and synthesized. The balance between the rates of synthesis and degradation of muscle protein pools, i.e., net muscle protein balance (NBAL), determines the amount of that protein in muscle.” – Assessing the Role of Muscle Protein Breakdown in Response to Nutrition and Exercise in Humans

When you go on any diet and restrict calories whole body MPS (muscle protein synthesis) declines after just a few days,

“In short-term human studies, fasting and postprandial MPS rates are downregulated within 5–10 days of 40% CR” – Prolonged Calorie Restriction Downregulates Skeletal Muscle mTORC1 Signaling Independent of Dietary Protein Intake and Associated microRNA Expression

Take home:

After about a week of chronic calorie restriction MPS falls below MPB and we begin to lose muscle mass. 

But exactly how/ why does MPS fall below MPB?

Thor?

NO, mTOR?

Lots of MPS going on here

At the cellular level muscle protein synthesis (MPS) is largely mediated by the mTOR pathway.

This is why leucine is so important with protein feedings.

Roughly 2(ish) grams of leucine in a meal will kickstart (supercharge) mTOR activity and MPS in the muscle cell  even with a lessen amount of total amino acids.

MPS (mTOR) is activated 2 ways (for our purposes):

1. You eat and provide the cell with energy (glucose) and/ or proteins, which in turn sets off the signal (mTOR) to build (use the energy and proteins provided)
2. You stress the muscle tissue (ie get swole) activating mTOR to being the process of rebuilding the tissue (with the energy available in the cell).

“the importance of mTOR signaling in promoting muscle growth is well appreciated by basic scientists and bodybuilders alike, the mechanisms underlying this process are still poorly understood, in part due to the difficulty of genetically manipulating multinucleate myocytes in vivo. Nonetheless, early studies of mTOR signaling in the muscle revealed that mTORC1 activation is associated with muscle hypertrophy.” – mTOR Signaling in Growth, Metabolism, and Disease

Two side notes:

1. Resistance training, even in a caloric deficit, activates mTOR, elevates MPS, and is one of the reasons its VITAL to continue to weight train hard during a deficit.
   • ingestion of protein combined with resistance training during this deficit is like a double shot of mTOR and MPS awesomeness
2. YOU DO NOT WANT mTOR on ALL THE TIME
   • ….mTOR run a muck is a bad thing ie. cancer. Like most things in biology the APPROPRIATE amount of mTOR at the right time is optimal and more, all the time, is really bad.

“While acute activation of mTORC1 signaling in vivo does promote muscle hypertrophy in the short-term, chronic mTORC1 activation in the muscle through loss of TSC1 also results in severe muscle atrophy, low body mass, and early death, primarily due to a lack the inability to induce autophagy in this tissue. Considering that turnover of old or damaged tissue plays a critical role in muscle growth, these results suggest that alternating periods of high and low mTORC1 activity, as occurs with normal feeding and fasting cycles, is essential for maintaining optimal muscle health and function” – mTOR Signaling in Growth, Metabolism, and Disease

Low mTOR and Why We Lose Muscle on A Diet?

Because of its role in MPS, low mTOR activation is at the heart of loss of muscle mass in a calorie deficit.

Food, energy (glucose), and amino acids (especially the AA Leucine), activate mTOR.

When on a diet, those can be in short(er) supply.

But we also need to remember that high protein intakes, even in a caloric deficit, help maintain muscle mass due to the maintenance of mTOR signaling equal that of the “fed” state,

“Consuming a high protein diet, particularly high-quality protein-containing meals, attenuates these declines and restores fasting and postprandial MPS rates to levels observed during energy balance”- Prolonged Calorie Restriction Downregulates Skeletal Muscle mTORC1 Signaling Independent of Dietary Protein Intake and Associated microRNA Expression

Fundamentally, the logic goes:

ingest protein = mTOR stimulation = MPS and muscle retention.

But the ability of high protein intakes during a caloric deficit to maintain pre diet mTOR has a limit.

4 months…

Calorie restricted, high protein diets, maintain mTOR signaling for 16 weeks,

“prolonged CR (16-weeks; 40% total energy requirements) led to downregulation of fasting mTORC1 signaling activity and inhibition of protein translation and phosphorylation (i.e., activity) of Akt, mTOR, p70S6K, and rpS6 under fasted conditions. The systematic downregulation of mTORC1 associated protein expression and activity, particularly the decline rpS6, was associated with diminished muscle protein content. These findings link the molecular regulation of mRNA translation initiation and, possibly MPS, with a measure of long-term muscle protein status in response to underfeeding. Contrary to our hypothesis, the high protein diet, fed as a percentage of total calorie intake, did not attenuate declines in mTORC1 signaling and muscle protein content compared to standard protein intake. Furthermore, the inhibition of mTORC1 associated protein translation during CR did not appear to be regulated by miR. Overall, findings from this study indicate that prolonged CR alters protein translation and downregulates mTORC1 activity.………

the observation that mTORC1 signaling was highly correlated with muscle protein content, suggests that mTORC1 responses to underfeeding are largely responsible for diminished protein content.” – Prolonged Calorie Restriction Downregulates Skeletal Muscle mTORC1 Signaling Independent of Dietary Protein Intake and Associated microRNA Expression

That means, high protein intakes can offset lowered MPS and help retain muscle that would otherwise naturally be lost on a diet for FOUR MONTHS.

Take Home:

MPS and mTOR signaling decreased after about a week of dieting.

MPS, via mTOR stimulation, is maintained in a high protein, calorie restricted diet for up to 16 weeks.

Why Intermittent Fasting MAY Retain Lean Body Mass:

Keep in mind, this comparison is assuming that both my Chronically Calorie Restricted group and my Intermittent Fasting group are performing the diets under the same conditions:

• Equal total weekly calorie deficit
• Equated total macronutrients (carbs, fats, proteins)
• Same activity levels

Intermittent Fasting works because it depletes the cells of glucose forcing the body into fat oxidation and ketosis.

Depriving muscle cells of glucose tends to make them much more sensitive to the ingestion of both glucose and amino acids and there is a rebound effect and supercompensation past initial baseline when they’re ingested following depletion.

This is why carb loading works when done correctly and the post workout protein shake used to be gospel.

If it takes a week of caloric restriction before we see decreased MPS, intermittent fasting may provide a “recharge” for the cells.

Intermittent Fasting continually restores mTOR activity and MPS, restarting the “week” of restriction before MPS would chronically fall low enough to affect whole body lean mass.

In contrast, chronic caloric restriction, or continuous fasting, once you pass that initial 5-10 days of restriction and MPS declines you’re never taking in enough energy to “recharge” the muscle cells and optimize mTOR expression and MPS when it is stimulated (post meal or training).

“IF may preserve FFM (fat free mass). Mechanistically, this could be explained if the catabolic phase of fasting was entirely compensated by the anabolic processes during complete refeeding. In animal models, fasting triggered fatty acid-derived ketone production and gluconeogenesis from amino acids, once liver glycogen was depleted. Conversely, resumption of calorie intake on non-fasting days to energy balance or above, increased circulating amino acids and insulin activating mTOR complex 1 pathways to promote muscle protein synthesis in rodents”-  Intermittent fasting: what questions should we be asking?

I Still Have Doubts About Maintaining Muscle Mass

The major question in my mind is,

What if the person is highly active, highly muscled and lean (low body fat %) ie athletes?

The VAST majority of the IF research that is done to this point on humans has some limitations.

Fun Fact: these limitations are always presented in the literature, however we NEVER hear about them in the popular media…that is soooooo weird, right?

IF research limitations:

1. The VAST majority of the IF research to date is on overweight and obese populations
2. The length of the studies tends to be short because one of the main problems with IF (especially alternate day and multiple day per week fasting) is that long term adherence tends to wane and the reliability of many long(er) term studies needs to be taken into question because its usually based on surveys and, well, people lie. In fact, they lie A LOT when it comes to their food habits.
3. Lean, highly muscled athletic people usually don’t just come that way. They exercise, hard, often, like almost every day. And I’m just guessing, the people in the IF “exercise” studies ain’t training all that hard that often.

We know that leaner, more heavily muscled are more prone to LOSING muscle mass in a caloric deficit than the overweight or obese,

“preserving FFM (fat free mass) during ER (energy restriction) appears to be extremely difficult for very lean male and female athletes, regardless of intense resistance exercise. In elite lean male bodybuilders (9.1% body fat prior to beginning ER),nine weeks of ER reduced percentage body fat to 5.0% but was accompanied by a significant loss ofFFM from 90.60 to 88.14 kg. Furthermore, in five lean athletic females and five female competitivebodybuilders, 12 weeks of ER in preparation for a contest resulted in a 5.80 kg loss of body weight,with 23.8% of this weight loss accounted for by reductions in FFMWith the evidence considered, it appears that adiposity has a protective effect against loss of FFM during ER and should therefore be of greater concern for lean individuals considering weight loss interventions.” – Intermittent Dieting: Theoretical Considerations for the Athlete

Does IF Keep You Jacked?

Don’t know…

Since the lean and muscular are more susceptible to losing lean mass in a deficit, we might not be able to say IF retains lean mass in all situations with all populations.

There is a definite possibility that without sufficient daily calories, high activity levels/ outputs, resting energy expenditures etc, IF could create an environment where proteolysis (the breakdown of muscle tissue for energy) takes place, possibly at an accelerated pace vs continuous energy restriction, since glucose (muscle and liver glycogen) would be run through quickly, there isn’t “abundant” fat to pull from, and muscle mass is both “excessive” and metabolically costly.

Right now, looks like no one really knows,

“Given the deficiency of research on IER (intermittent energy restriction) in the context of athletes, optimal nonlinear dietary strategies are yet unknown.” – Intermittent Dieting: Theoretical Considerations for the Athlete

“Our analyses also revealed a major weakness in that most fasting studies recruited sedentary subjects or low-level athletes, often without well-matched controls.” – Exercise Training and Fasting: Current Insights

Update:

Literally, the day I was going to publish this blog, Dr. Bill Campbell who is running the ONLY lab that is actively doing research on physique based athletes, had this study published,

Intermittent Energy Restriction Attenuates the Loss of Fat Free Mass in Resistance Trained Individuals. A Randomized Controlled Trial

Here’s what they found,

“this is the first investigation, to our knowledge, to demonstrate a preservation of fat-free mass and resting metabolic response to a 2- day carbohydrate refeed during an energy restricted diet in lean, resistance trained males and females. The attenuation of these adverse responses to caloric restriction may have been dependent on the restoration of true energy balance (or the interruption of continued energy restriction) in the carbohydrate group. Our findings suggest that, in lean individuals, the inclusion of resistance training, high protein intakes, a slow rate of weight loss, and periodic carbohydrate refeeding may prevent some of the adverse responses to prolonged energy restriction.” 

This study DID NOT use intermittent fasting, it used different rates of continuous caloric restriction, one group at a continuous 25% daily restriction and one group at a weekly 35% restriction with a two day weekend refeed at 100% of energy (carbohydrate) balance.

In my mind it definitely helps to bolster the argument that alternate day or intermittent daily fasting could attenuate the loss of lean mass associated with being in a caloric deficit as long as the “refeed” days were able to refill muscle glycogen.

Oh, and it had these graphs,

Both groups lost roughly the same amount of fat, but the refeed group had 3 weirdos who GAINED appreciable muscle mass even in an overall deficit with a weekly refeed.

The real take-home here is that while there are most defiantly trends, individual response may does vary.

But to me it definitely lends credence to the idea that under the right conditions, you CAN retain more lean mass with IF.

What About Weight FAT Regain Post Diet?

Since IF is often used as a temporary measure to lose weight we should look at how well it keeps the fat off.

And there really isn’t much data on the efficacy of IF for long term weight maintenance for those who have used it as a means of caloric restriction.

Truth is, like most diets, people quit once they achieved a desired weight (actually before that point) so, to me, its unfair to look at IF and judge its effectiveness long term in weight maintenance post diet.

Sure, some people practice intermittent fasting on the regular, but for them its a lifestyle, built in to how they live day to day.

Not a weight loss program.

The reality is, if you’re in caloric balance, you’re going to be weight neutral regardless of how and when you eat.

There is however a theoretical construct for how IF may help protect against FAT regain post diet.

Yo-Yo Dieting

Long story short.

• You chronically diet.
• You lose lean body mass and your energy expenditure naturally lowers
• Your hormonal and metabolic mileu changes.
• The longer and deeper the caloric restriction, the more the mileu changes unfavorably toward excess energy consumption post energy restriction.
• Fat cells become hypersensitive to excess energy post energy restriction and YOU MIGHT GROW NEW FAT CELLS IN RESPONSE,
  • • Mostly you’ll probably just refill the old fat cells, but who needs more of those assholes around, right?
• You get fat(er) post diet

figure 2 from Intermittent Fasting: Theoretical Considerations for Athletes

While you WONT GAIN WEIGHT or FAT if you end the diet and eat at caloric balance, post diet, your body is probably sending the signal to overconsume based on your current, now lower than pre diet, needs.

In fact, there is some evidence that post diet your body will exhibit the drive to overconsume calories until you regain the FFM (fat free mass) lost during the diet phase.

Sounds great, and it would be if FFM came back to post diet levels quickly and “efficiently”.

Alas, it DOES NOT.

Lean mass anabolism (muscle, bone, etc) is a very time and resource consuming process.

Fat Accumulation?

A really easy process comparatively.

This may be why FAT is primarily accumulated after a prolonged diet if you overconsume calories.

Leaner Dieters Might Get Fatter Over Time

Post diet caloric partitioning towards fat accumulation seems to be especially prevalent in lean individuals.

The leaner you are before the diet the greater “fat overshoot”  you’re at risk for and may be subject to increasing body fat percentages following subsequent cycles of dieting.

Remember, leaner people are also subject to greater lean body mass losses when dieting and in the fat overshoot model the body is regaining weight until it recaptures the pre-diet level of FFM (fat free mass).

Be damned how much fat mass it accumulates in this “overshoot” period.

This can lead to a “cycling” of weight that increases the relative (and absolute) body fat over time,

“these studies reinforce the contention that dieting to lose weight and weight cycling most strongly predict future weight gain in those who are lean than in those who are with overweight/obesity. By extension, they reinforce the plausibility that at least in the people without obesity, each cycle of weight loss/regain is accompanied by a greater gain of body fat than is lost. Such a phenomenon referred to as weight (or fat) overshooting is directly supported by the classic longitudinal study of semistarvation and refeeding—the Minnesota Experiment—conducted in young men in the normal range of BMI. During their nutritional rehabilitation after losing 25–29% of their body weight over 24 weeks of semistarvation, they showed fat overshooting of 4 kg on average but ranging between 0 and 9 kg, with those showing higher fat overshooting being the leanest, as evidenced from an inverse exponential relationship between the kg of fat overshot and initial (pre-starvation) body fat%.” – How dieting might make some fatter: modeling weight cycling toward obesity from a perspective of body composition autoregulation

How Does Dieting Make Me Fatter?

One of the theories as to why fat cells become more sensitive post diet is that with prolonged calorie restriction the fat cells release…you guessed it….fats, and shrink.

This may put a mechanical stressor on the cell as the inner contents shrink and the outer cell matrix doesnt resulting in inflammation to the extra cellular matrix (cell wall).

The fat cell will try to stop the stress on the cell and remove the inflammation response by regaining cell size, ie fattening back up, restoring homeostasis.

This is probably done through the release of hunger inducing hormones while downregulating the release of satiety inducing hormones, thereby increasing hunger and the drive to eat.

“we believe that adipocytes that are under stress are preconditioned for renewed fat accumulation and trigger the host to increase energy intake. Therefore, in this scenario, adipocytes would start to accumulate fat again, and the increasing cell volume would reduce the mechanical stress — which means weight regain for the host” – Mechanisms of weight regain after weight loss — the role of adipose tissue

IF May Help Mitigate The Hormonal Response

The deplete- refeed cycle of IF may not only help retain FFM in a deficit it may also help protect against adipocyte hyperplasia, ie growing more fat cells and this fat overshoot post deficit.

How does IF do this?

By restoring levels of circulating hunger/ satiety related hormones.

“a number of the adverse metabolic and hormonal outcomes associated with weight loss have been reported to be quickly reversed upon restoration of EB (energy balance)…… There is evidence that levels of leptin and thyroid hormones can be temporarily increased following short-term overfeeding. In one trial, the subsequent elevation in leptin following overfeeding resulted in a 7% increase in TDEE [118]. These findings have caused speculation among some athletes and coaches that refeed periods may stimulate an increase in circulating levels of these regulatory hormones leading to temporarily inflated metabolic output and reversal of adaptive mechanisms associated with ER. However, it remains to be seen whether the same stimulatory effect on leptin release and thyroid activity can be achieved with controlled refeeding during IER where participants temporarily increase energy intake to levels for EB, as opposed to overfeeding. If this was indeed the case, the stimulatory effects on energy expenditure and fat loss via increased thyroid and leptin output, in conjunction with leptin’s influence on satiety, would likely decrease the drive to eat—enabling better dietary adherence—and facilitate greater weight loss efficiency“- Intermittent Fasting: Theoretical Considerations for Athletes

Maybe, maybe not…

We need to find out.

But Intermittent Fasting may be a strategy to wave energy intake in such a way that metabolic and hormonal responses are such that fat cells don’t enter into this stressed state.

Ohh and just to top it off, when we really stress the fat cells (through dieting) and then quickly reintroduce energy in a surplus, you might grow new fat cells..

fig.3 Intermittent Fasting: Theoretical Considerations for Athletes

So a form of dieting like Intermittent Fasting which may help control hunger and satiety during weight loss and regain could be a boon for fighting this fat overshoot associated with typical yo-yo dieting.

There’s a lot more to intermittent fasting, and we’ll go through those, intermittently because this article took an entire month and about 15-20 total hours….but the plan is to look at how fasting can influence the ability to switch fuel sources, typically termed,

Metabolic Flexibility.