Intermittent Fasting Dilemma: How Many Meals Per Day Should You
by Ori Hofmekler: The Best Foods that Fill You Up and Boost Your
Metabolism and Shed Pounds
- There is
an emerging consensus that narrowing the window of time that you
consume food may have enormous health benefits and also help you
reduce the percentage of body fat.
of intermittent fasting include reduced oxidative stress; increased
insulin sensitivity; increased mitochondrial energy efficiency;
and increased capacity to resist stress, disease, and aging
- Most intermittent
fasting programs, including alternate day fasting, once or twice
a week fasting, and once every other week fasting are, in the
best case, only partially beneficial as they do not accommodate
your circadian rhythm
- Your body
is programmed for nocturnal feeding, and the one meal a day regimen
is the only intermittent fasting (IF) program that accommodates
your innate circadian clock and maximize the beneficial effects
you get from IF on a daily basis
- Most foods
negate the effects of fasting, but there are some exceptions.
Foods that can be safely eaten without compromising your fast
include fast-assimilating nutrient-dense foods such as quality
whey protein, green vegetables and berries
fasting approach has been getting increased recognition these days.
But 10 years ago, it was a different story.
When I introduced
The Warrior Diet concept about 12 years ago, it was highly
criticized by mainstream fitness authorities as an "extreme and
dangerous" approach to dieting. Telling people to skip breakfast
and lunch was like committing dietary heresy.
Diet book was the first to offer a diet plan based on intermittent
fasting. Yes, at that time, it felt like I was the only person in
the world arguing for substituting the frequent feeding approach
of several meals per day with one meal per day.
Then, a few
years later, studies on intermittent fasting (conducted by Dr. Marc
Mattson/NIH) shocked the world with the news that this "radical"
pattern of eating yielded a substantial increase in the lifespan
of rodents along with outstanding improvements in major health markers
including insulin sensitivity, body composition and neuro-regeneration
capacity. Since then, a growing number of health and fitness gurus
have been jumping on the intermittent fasting (IF) wagon. Just Google
intermittent fasting and check for yourself.
and many bloggers are now claiming credit for their IF plan. The
variations include fasting all day, every other day, every third
day, twice per week, once per week, or once every other week. Some
recommend skipping breakfast or skipping dinner, whereas others
advise "eating only when hungry," or "not eating when not hungry."
even Andrew Weil is now blogging in favor of IF. According to Weil,
simply eating three meals per day with no snacks should be called
in America "a form of intermittent fasting"… yes indeed, to be popular
in this country, a diet plan must be easy to follow… But fasting
is never easy. And there is always a reason to avoid fasting. Virtually
all IF websites are happy to give you these reasons.
Reasons (or Perhaps Excuses) to Avoid Fasting
They tell you:
don't fast if you're hypoglycemic; don't fast if you're diabetic;
don't skip meals if you suffer from heartburn, or don't get yourself
overstressed with fasting if you're already overstressed.
It is also
very popular these days to say, "fasting is not for everyone"… hence,
if you're looking for a reason to avoid fasting, that's the easiest
one to pick.
Note that there
are cases that may prohibit long-term fasting, such as with young
children, type I diabetics (on insulin medication), or in the case
of clinical myopathy (muscle wasting disease). Nonetheless, even
in these or similar cases, the exclusion of fasting is not necessarily
wise, as fasting could be potentially useful as a therapeutic strategy.
Fasting has shown to improve conditions of metabolic disorders,
lower the need for insulin medication, and help relieve inflammation.
So how can
fasting benefit you?
To figure that
out, you need to take a look at the science behind fasting. You
need to know how fasting induces its beneficial effects on your
body, and what meal frequency allows you to take maximum advantage
Benefits Your Body
acknowledged three major mechanisms by which fasting benefits your
body, as it extends lifespan and protects against disease:
oxidative stress – Fasting decreases the accumulation
of oxidative radicals in the cell, and thereby prevents oxidative
damage to cellular proteins, lipids, and nucleic acids associated
with aging and disease.
insulin sensitivity and mitochondrial energy efficiency
– Fasting increases insulin sensitivity along with mitochondrial
energy efficiency, and thereby retards aging and disease, which
are typically associated with loss of insulin sensitivity and
declined mitochondrial energy.
capacity to resist stress, disease and aging – Fasting
induces a cellular stress response (similar to that induced by
exercise) in which cells up-regulate the expression of genes that
increase the capacity to cope with stress and resist disease and
There is Only
One Fasting Regimen that Makes Sense in Practice...
So given the
above, what kind of fasting regimen will benefit you most?
If you learn
the facts behind human biology and how your body is programmed to
thrive, you will realize that almost every popular IF program today,
including alternate day fasting, once or twice a week fasting, and
once every other week fasting are, in the best case, only partially
Most IF programs
cannot and will not yield the results you're looking for. The reason:
Your body operates around a 24-hour cycle that dictates your innate
circadian clock. Most IF programs are not designed to accommodate
Most IF Programs
Disregard Your Circadian Clock
clock is an essential factor in your life as it controls all your
circadian rhythms. Called the Suprachiasmatic Nucleus (SCN), it
is located in your hypothalamus, where it regulates how your autonomic
nervous system operates along with your hormones, your wake and
sleep pattern, your feeding behavior, and your capacity to digest
food, assimilate nutrients, and eliminate toxins.
when you go against your innate clock?
If you're routinely
disregarding your innate clock – working during sleeping hours,
or feeding at the wrong time – you'll sooner or later pay the consequences
with symptoms that may include disrupted sleep, agitation, digestive
disorders, constipation, chronic fatigue, chronic cravings for sweets
and carbs, fat gain, and lower resistance to stress.
Note that chronic
disruptions in circadian rhythms have been linked with increased
risk for chronic inflammatory disease and cancer. Most IF programs
overlook this issue. Their timing of feeding is either random or
But the timing
of your feeding is not something you can afford overlooking. There
is a dual relationship between your feeding and innate clock. And
as much as your innate clock affects your feeding, your feeding
can affect your innate clock. Routinely eating at the wrong time
will disrupt your innate clock and devastate vital body functions;
and you'll certainly feel the side effects as your whole metabolic
system gets unsynchronized.
Feeding Time is at Night
So when is
your right feeding time?
Your body is
programmed for nocturnal feeding. All your activities, including
your feeding, are controlled by your autonomic nervous system which
operates around the circadian clock. During the day, your sympathetic
nervous system (SNS) puts your body in an energy spending active
mode, whereas during the night your parasympathetic nervous system
(PSNS) puts your body in an energy replenishing relaxed and sleepy
These two parts
of your autonomic nervous system complement each other like yin
and yang. Your SNS, which is stimulated by fasting and exercise,
keeps you alert and active with an increased capacity to resist
stress and hunger throughout the day. And your PSNS, which is stimulated
by your nightly feeding, makes you relaxed and sleepy, with a better
capacity to digest and replenish nutrients throughout the night.
This is how your autonomic nervous system operates under normal
But that system
is highly vulnerable to disruption.
If you eat
at the wrong time such as when having a large meal during the day,
you will mess with your autonomic nervous system; you'll inhibit
your SNS and instead turn on the PSNS which will make you sleepy
and fatigued rather than alert and active during the working hours
of the day. And instead of spending energy and burning fat, you'll
store energy and gain fat. This is indeed a lose-lose situation.
Unfortunately, most IF programs fail to recognize this.
Most IF Programs
Miss the Boat
a brief look at some of the most notable IF regimens.
day fasting. This program seems to be the most difficult
to handle. Followers of this regimen have been complaining of
a significant increase in hunger and a chronic excruciating desire
to eat on their fasting day. But what makes this IF program even
more problematic is the adaptability issue – as followers seem
to be just as hungry on the last day of fasting as on their first
day. There have also been reports of side effects such as sleeping
disorders, constipation, and a persistent fatigue among the followers.
day fasting has one major caveat: the 24 hours fast seems too
long to handle (both physically and mentally). This regimen has
been shown to cause sleeping issues due to the fact that night
fasting turns on the SNS which keeps you alert and anxious rather
than relaxed and sleepy during the night – thereby disrupting
your sleep-wake cycle.
based on epidemiological evidence, it seems that the human body
is programmed for a daily cycle of 24 hours and its optimum fasting
threshold should be within the range of 18 hours. Anything beyond
that may put your body in a starvation-catabolic mode which if
done chronically, may lead to metabolic shutdown's symptoms such
as underactive thyroid, decreased sex hormones, loss of muscle
mass, and declined energy.
a week or twice a week fasting. Both once or twice
a week seem to be easier to follow than the alternate day fasting,
only that these regimens are less effective than the alternate
day fasting. Eating 3-4 square meals every day for most of the
week is a serious compromise of the original IF concept, as it
minimizes the weekly impact of fasting to merely 1-2 days per
every other week or every month. Worse than that
is "fasting every other week" or every month. These IF programs
seem to target the typical American dieter who is constantly looking
for an "easy to follow" program to lose weight or improve health.
The motto "better fasting once or twice per month than not fasting
at all" is just an excuse to choose mediocrity over excellence.
dinner. The skipping dinner approach goes against
your innate clock. This regimen may cause sleep disorders and
similar side effects as the alternate day fasting diet, only that
skipping dinner is less effective than the alternate day fasting
due to its shorter fasting time.
of skipping dinner argue that breakfast is an important meal and
should not be skipped. Nonetheless, the science clearly indicates
the opposite – the typical breakfast antagonizes the SNS and disrupts
healthy circadian rhythms.
growing evidence that the typical breakfast is the most harmful
meal of the day. A study by the Human Nutrition Research France1 indicated
that the typical high energy breakfast caused major adverse effects
in the short and long terms. These included a strong inhibition
of fat burning throughout the day, increase in serum triacylglycerol,
decrease in HDL (good cholesterol), and over-glycemic reactions.
The researchers concluded that high-energy breakfast does not
appear to be favorable to health; they also indicated that the
study's results do not support the current advice to consume more
energy at breakfast.
the average consumption of energy at breakfast among breakfast
eaters is between 15-20 percent of total daily energy intake.
The typical breakfast composition: 12 percent of calories from
protein, 25 percent from fat and 63 percent from carbohydrates.
coming from epidemiological surveys have been indicating that
the consumption of a high energy breakfast leads to a significant
higher energy consumption for the whole day. Furthermore, a big
breakfast has shown to yield only a limited satiety effect which
lasts merely 2 hours after breakfast. Overall, science confirms
that the typical high carbohydrate breakfast tends to increase
fat storage, increase body weight, and increase the risk for cardiovascular
disease and long term health.
some of the healthiest societies in the past did not eat breakfast;
the word breakfast was not part of their vocabulary. The typical
breakfast did not exist during Biblical times. In the original
Hebrew text of the Bible, breakfast is called "pat shacharit"
which meant a tiny piece of bread at dawn – nothing more. And
there isn't a single mention of breakfast in the new testament;
supper was the main meal of the day (hence, the Last Supper).
The ancient Greeks and Romans were very particular about eating
their main meal at night. According to Plutarch and Cicero, only
slaves and farm animals were fed breakfast and lunch, as contrary
to free men and soldiers who ate one meal per day at night.
breakfast. Skipping breakfast is certainly a better
idea than skipping dinner. This protocol seems to be particularly
viable for those who exercise during the morning hours. In this
case a specially modified high protein lunch can serve as a post
exercise recovery meal. The skipping breakfast regimen is nevertheless
of this approach speculate that skipping breakfast after a night
fast yields about 16-18 hours of fasting including sleeping time.
That seems good in theory but in reality this regimen doesn't
yield as many hours of fasting as claimed.
Here is why:
What really counts is your net fasting time, the gap between your
meals minus digestion time. It typically takes your body between
6-8 hours to fully digest a hearty evening meal (depends on your
meal density – content of protein and fat, etc). If for instance
you start your evening meal at 8pm and finish eating at 9-10pm,
your body will only shift into a fasting state by the early morning
hours (about 3-6am). Hence, your body will not be in a fasting
state for most of the night.
So when you
skip your morning meal until noon, your net fasting time is merely
6-9 hours. That might be good but not enough to grant maximum
impact. So what is the ideal way to fast? What should be your
right meal frequency?
The One Meal
Per Day Plan
The one meal
per day plan is the only regimen that can accommodate your innate
clock and maximize the beneficial effects you get from IF on a daily
basis. That's if your food choices and meal timing are adequate.
The one meal
per day yields 14-16 hours of net fasting time provided that you
have a window of about two hours to finish eating. And in the case
that you have a feeding window of four hours, you're still left
with 12-14 hours of daily net fasting – sufficient to get you the
results you're looking for.
Other IF regimens
yield a net fasting time that is either too long or too short. And
most of these programs cause adverse side effects as they fail to
accommodate your innate clock.
Can the One
Meal Per Day Regimen Satisfy Your Physical Needs?
The one meal
per day regimen can accommodate your physical needs, but you need
to know how to modulate this regimen to fit your specific condition.
For instance, if you routinely exercise during the day you'll need
to feed your muscle after your workout with a low glycemic recovery
meal made with fast assimilating protein, such as that from high
quality whey. You can also feed your muscle before your workout
as this will help increase your capacity to sustain intense exercise.
Can One Meal
Per Day Accommodate Intense Training?
If you're engaged
in max strength conditioning or MMA training, you should feed your
muscle before and after your workout. Only in this case, your pre-workout
meal should consist of protein and carbs. Note that max strength
exercise work your fast glycolytic muscle fibers (Type IIB white
fibers), which are inherently carb dependent. Having fast assimilating
protein and carbs before your workout can help load glycogen in
your muscle, nourish your fast fibers; and boost your max strength
Your best choice
for your pre-exercise and post-exercise meal is quality whey protein,
derived from raw milk of pasture-fed or grass-fed cows. For pre-workout
carbs use nutrient dense fruits such as berries, which can swiftly
fuel your muscle with carbs and antioxidants and thereby enhance
your performance while reducing the oxidative stress in your muscle
to allow a faster recovery after your training.
Having an oatmeal
or porridge an hour before training can be a viable option in case
you're engaged in prolonged intense training sessions. Again, make
sure your post-exercise recovery meal is low glycemic with no sugar
added, to support your insulin and accommodate your IF. High glycemic
meals negate the benefits you get from fasting.
Can Be Safely Consumed During Fasting
So is it ok
to eat whey protein during fasting? What other foods could be safely
consumed during the fast? How often can you eat these foods and
In the Warrior
Diet Book, I introduced the concept of "undereating" as a viable
alternative to water fasting. Undereating means minimizing your
food intake to small servings of specific foods, which you're allowed
to consume in a certain frequency during your fast. If done properly,
undereating can yield the same benefits of fasting and even more.
Let me explain.
negate the effects of fasting, but there are some exceptions. Some
foods can be safely eaten without compromising your fast. These
include fast assimilating nutrient-dense foods such as quality whey
protein, green vegetables and berries. But you need to know how
much you're allowed to consume and how often.
these foods complimentary to fasting are the following properties:
rich in antioxidant and anti-inflammatory nutrients
- They target
the same genes as fasting
- They induce
similar effects to those you get from fasting
servings of whey protein, green vegetables or berries during your
fast isn't just ok, it may actually increase the benefits you get
assimilating, these foods nourish your body without taxing your
digestion, as they enhance the anti-inflammatory and metabolic modulating
effects of your fasting. They also increase your body's antioxidant
defenses against reactive oxygen species (ROS) which tend to accumulate
in your body during fasting and exercise as byproducts of fat breakdown
and detox. ROS are unstable and highly reactive molecules which
search, bind to, and destroy cellular lipids, proteins and DNA.
The above foods help protect your body from that oxidative damage.
non-denatured whey protein, green vegetables and berries contain
nutrients (antioxidant polyphenols, flavons, resveratrol, cyanidins,
indoles, in plants; leucine, calcium and immune factors in whey)
that target the same genes and pathways as fasting and exercise.
Most notable among these are the SIRT-1 gene (the longevity gene)
and the transcriptional co-activator PGC-1?, known to counteract
oxidative stress and inflammatory pathways associated with declined
health and increased mortality. SIRT-1 and PGC-1? increase mitochondrial
biogenesis and thereby prevent the typical decline in mitochondrial
function (and decreased cellular energy) associated with aging and
and How Often Can You Eat These Foods?
You can have
a small serving of whey protein (20-30g net protein) every 3-6 hours,
depending on your level of physical activity. Those who do not exercise
can have one or two servings of whey protein during their daily
you can have 8oz of berries or green vegetables (or freshly squeezed
green vegetable juice) every 3-6 hours while you fast. Do not mix
berries with whey unless you use that blend as a pre-workout meal
to support your strength conditioning.
Having a small
serving of whey protein, berries or greens will hardly affect your
body's negative energy balance throughout the fast. Hence, if you
eat them at the right amount and frequency, the above foods will
not compromise your IF.
It may take
science another 10-15 years to figure out the difference between
water fasting and that mode of undereating. Nonetheless, based on
what we know today about the nutritional properties of whey, berries
and greens, and based on testimonials coming from Warrior Diet followers,
and my own experience, I can tell you that having these foods during
the fast isn't just making it easier, but also makes it more effective
and beneficial to your body than a sheer water fast.
- The one
meal per day is the only regimen that can maximize the benefits
of your IF on a daily basis.
- Eat your
main meal at night to accommodate your circadian clock.
- Whey protein,
berries and greens compliment your fast if you know how much to
consume and how often.
- If you exercise
during the day, have a recovery meal after your workout consisting
of whey protein with no sugar added.
- If you're
engaged in super intense training, have a pre-workout meal consisting
of whey protein and berries.
- If you're
engaged in prolonged intense training, have a bowl of oatmeal
with your whey protein about an hour before your workout.
Behind Circadian Rhythms
regulation of immune response and resistance to disease. Recent
studies published by the PNAS, January 2012, revealed the existence
of a specific nuclear receptor that mediates circadian regulation
of innate immunity and resistance to disease. This circadian regulation
is controlled by an internal mechanism which is highly conserved
in humans and animals and orchestrates the daily patterns of diverse
physiological processes such as wake/sleep cycles, feeding, and
to the researchers, many diseases exhibit a disrupted circadian
rhythmicity in their pathology… and lifestyles that disrupt the
inherent timing system, such as chronic shift work, are associated
with increased risk of cancer, metabolic disorders, cardiovascular
disease and cerebrovascular disease.
indicated that inflammatory diseases in particular exhibit strong
time-of-day symptoms. They concluded that in humans, circadian
rhythms are driven by a complex of feedback loops that mediate
gene activities throughout a period of 24 hours and speculated
that daily risk of infection is likely to be a direct consequence
of wrong timing of activity and feeding.
24 hours cycle. A study by Czeisler et al. at Harvard
University found that the range for normal healthy adults of all
ages to be quite narrow: 24 hours and 11-16 minutes. This innate
clock resets itself daily to the 24 hour cycle of the Earth's
sympathetic/parasympathetic division. Based on biology
textbook (see Wikipedia – autonomic nervous system), the sympathetic
and parasympathetic divisions typically function in opposition
to each other. Consider sympathetic as "fight or flight" and parasympathetic
as "rest and digest" or "feed and breed."
nervous system – corresponds with energy generation, and inhibits
digestion. The parasympathetic nervous system – promotes "rest
and digest" response, along with calming of the nerves.
and the innate clock. According to a 2010 study, completed
by the Lighting Research Center, daylight has a direct effect
on performance and wellbeing. The research showed that students
who experience disruption in lighting schemes in the morning experienced
disruptions in sleep patterns. Removing circadian light in the
morning delays the dim light melatonin onset by 6 minutes a day,
for a total of 30 minutes for five days.
and the innate clock. The feeding clock mechanism is
the same as the light/dark driven clock controlled by the innate
master clock – the suprachiasmatic nucleus (SCN) which is a cluster
of neurons in the hypothalamus. But the machinery that inter-regulates
feeding and the innate clock is located in a different part of
the hypothalamus (DMA).
reveal that mice on a daily 4 hours feeding window shifted their
circadian rhythms so that their peak physical activity was before
feeding and not after. This rhythm continued even if the mice
were kept in constant darkness. Hence, the animals are inherently
programmed for post action feeding and not the other way.
If You Didn’t
Fast, Don’t Eat Breakfast
When you think
about it from an evolutionary perspective, the idea of "having to
wait for a meal"… especially the first one of the day, is actually
so intuitively logical that it is somewhat tragic that people misunderstand
the statement that "breakfast is the most important meal of
the day" as an invitation to start binging the very moment
they get up, instead of waiting for lunch or even dinner to begin
stuffing junk down their gullets.
is quite ironic, because if we take a look at the etymological origins
of the word "breakfast," it's plain obvious that this is not - as
in Germany, where it is called "Frühstück" = "the first piece,"
the first meal of the day, but the meal that breaks the fast! Unfortunately,
though, fasting has become something, the average TV watching couch-potato
of the Western hemisphere is a total foreigner to.
to the endlessly debated question of whether or not you should have
breakfast is – as long as we understand "breakfast" correctly, i.e.
as "breaking the fast" – stupidly simple: Without fasting there
is no "break(ing the)fast"! Our diurnal metabolic rhythm is
geared towards cyclic fasting and feeding patterns, where the feeding
hours have always been shorter than the fasting hours.
Hofmekler, author of The
Warrior Diet, The
Anti-Estrogenic Diet, Maximum
Muscle Minimum Fat, and Unlock
Your Muscle Gene, is an expert on how to improve your health
2012 Dr. Joseph Mercola