Why Intermittent Fasting Is More Effective Combined With Ketogenic Diet from Dr. Mercola
Why Intermittent Fasting Is More Effective Combined With Ketogenic Diet from Dr. Mercola
July 02, 2018 • 107,708views
Story at-a-glance
Fasting
upregulates autophagy and mitophagy — natural cleansing processes
necessary for optimal cellular renewal and function. It also activates
stem cells and stimulates mitochondrial biosynthesis
Most of these
rejuvenating and regenerating benefits occur during the refeeding phase,
not the “starvation” phase. The same holds true for nutritional
ketosis, which produces the greatest benefits when pulsed
Recent research
highlights the importance of nutritional ketosis when intermittently
fasting. While the participants lost about 3 percent of their body
weight by eating all of their food within eight consecutive hours each
day, by not altering their dietary choices, important disease parameters
remained unimproved
Metabolic
health parameters that did not significantly improve included visceral
fat mass, diastolic blood pressure, LDL cholesterol, HDL cholesterol,
triglycerides, fasting glucose and fasting insulin
Cyclical
ketosis provides many of the same health benefits associated with
intermittent fasting, and when done together, most people will
experience significant improvements in their health, including but not
limited to mere weight loss
By Dr. Mercola
Fasting has been used for thousands of years to keep us well, and
it’s the most profoundly effective metabolic intervention I know of. Not
only does it upregulate autophagy and mitophagy — natural cleansing
processes necessary for optimal cellular renewal and function — but it
also triggers the generation of stem cells. The cyclical abstinence from
food followed by refeeding also massively stimulates mitochondrial
biosynthesis.
There’s even evidence to suggest fasting can help prevent or even
reverse dementia, as it helps your body clean out toxic debris. By
lowering insulin, you also increase other important hormones, including
growth hormone (known as “the fitness hormone”), which is important for
muscle development and general vitality.
Most of these rejuvenating and regenerating benefits occur during the
refeeding phase, not the “starvation” phase. The same holds true for
nutritional ketosis, which produces the greatest benefits when pulsed.
I’ve written a number of articles on both of these topics. Here, the
focus is on why these two strategies work best when combined.
Fasting Is a Powerful Tool for Rejuvenation and General Health
Research shows fasting is a powerful lifestyle tool for combating obesity, insulin resistance
and related health problems, including cancer. The reason for this is
because when autophagy increases, your body starts breaking down and
recycling old protein, including beta amyloid protein in your brain
believed to contribute to Alzheimer’s. Then, during the refeeding phase,
growth hormone increases, boosting the rebuilding of new proteins and
cells. In other words, it reactivates and speeds up your body’s natural
renewal cycle.
While water-only fasting can be extremely beneficial for those struggling with excess weight and/or Type 2 diabetes,
compliance can be difficult. Fortunately, research has confirmed that
similar results (albeit not as profound) can be achieved through intermittent fasting,
i.e., following a meal-timing schedule where you’re fasting for at
least 16 hours every day and eating all of your meals within eight
consecutive hours.
There are also other intermittent fasting plans where you
dramatically cut back on your calories for a certain number of days each
week, while eating normally during the remainder. The 5-to-2 intermittent fasting plan is one such example. The fasting mimicking diet,
developed to match the effects of water-only fasting, is another. Most
if not all of these plans have similar benefits, which include:1,2,3,4
Upregulating autophagy and mitophagy
Increasing growth hormone by as much as 1,300 percent in women and 2,000 percent in men,5 thereby promoting muscle development and vitality
Shifting stem cells from a dormant state to a state of self-renewal
Preventing, slowing the progression of, and reversing Type 2 diabetes
Boosting mitochondrial energy efficiency and biosynthesis
Reproducing some of the cardiovascular benefits associated with exercise
Boosting production of brain-derived neurotrophic
factor, which stimulates creation of new brain cells and triggers brain
chemicals that protect against brain changes associated with Alzheimer’s
and Parkinson’s disease7
New Research Questions Effectiveness of Intermittent Fasting When Still Eating Poorly
While intermittent fasting may sound like a panacea against ill
health and excess weight, it alone may not provide you with all of these
benefits. The quality of your diet plays an important role if you’re
looking for more than mere weight loss. More specifically, recent
research highlights the importance of nutritional ketosis when
intermittently fasting.
The study8,9
in question examined the effects of intermittent fasting on weight loss
and metabolic disease risk parameters in 23 obese volunteers. The study
lasted for three months. Between 10 a.m. and 6 p.m., the participants
were allowed to eat whatever they wanted in any quantity. For the
remaining 16 hours, they were only permitted water or calorie-free
drinks. The outcomes were then compared to a nonintervention control
group from a previous fasting trial.
Overall, participants consumed about 350 fewer calories per day and
lost just under 3 percent of their body weight. Systolic blood pressure
also dropped about 7 mmHg, compared to the historical control group.
Lead author Krista Varady, associate professor at the University of
Illinois at Chicago, commented on the results saying,10
“The take-home message from this study is that there are options for
weight loss that do not include calorie counting or eliminating certain
foods.”
While these findings are similar to other intermittent fasting
studies, the participants’ weight loss was slightly less than what’s
been observed in other studies. Trials of alternate-day fasting and the
5-to-2 fasting plan have found people lose between 3 and 8 percent in
eight to 52 weeks. According to the authors, “We speculate that this
difference in weight loss is due to greater overall caloric restriction
achieved with other forms of intermittent fasting …”
While this may sound “good enough,” there’s an important detail that
needs to be addressed. While participants did lose weight, other
metabolic health parameters did not significantly improve compared to
no-treatment controls, including visceral fat mass, diastolic blood
pressure, LDL cholesterol, HDL cholesterol, triglycerides, fasting
glucose and fasting insulin.
Weight Loss Alone Won’t Fix Your Health Problems
As I’ve repeatedly mentioned, one of the key benefits of intermittent fasting is normalizing your glucose and insulin levels
— along with many other biological metrics, including all of the ones
mentioned above — and that simply didn’t happen here. The question is
why? I believe the answer is fairly obvious, based on the evidence. The
participants were not instructed to alter WHAT they ate, and if they
were anything like a majority of Americans, a large portion of their
diet was likely processed food and probably even fast food.
The issue of food choices was a sticking point for me when I interviewed Varady on her alternate-day fasting diet
back in 2014. That particular plan consists of eating just 500 calories
every other day, but what form those calories take is up to the
individual. At the time, I stressed the importance of eating a diet high
in healthy fats, moderate in protein with unrestricted amounts of fresh
vegetables to optimize overall health on any intermittent fasting
program.
The reason for my objection to not including specific guidelines on
food choices was exactly what her latest study shows — unless you also
balance your macronutrient ratios, you might lose weight but you’ll
forgo many of the most important health benefits. If you lose weight but
don’t move the needle on glucose, insulin and other disease risk
parameters, then the benefit is little more than cosmetic.
For Optimal Health, Combine Intermittent Fasting With Cyclical Nutritional Ketosis
So, while the featured study presents intermittent fasting as a
successful weight loss method, from my perspective it really highlights
the importance of combining intermittent fasting with cyclical nutritional ketosis.
The ketogenic diet provides many of the same health benefits
associated with fasting and intermittent fasting (listed above), and
when done together, most people will experience significant improvements
in their health — including not just weight loss, which is more of an
inescapable side effect of the metabolic improvements that occur, but
other benefits such as:
Improved insulin sensitivity, which iskey
for preventing insulin resistance, Type 2 diabetes and related
diseases. Studies have shown diabetics who stick to a ketogenic diet are
able to significantly reduce their dependency on diabetes medication.
Many have even successfully reversed their diabetes this way.11 Having a healthy insulin level will also lower your risk of Alzheimer’s, as dementia and insulin resistance are closely linked.12
Increased muscle mass. Ketones are
structurally similar to branched-chain amino acids, and since they tend
to be preferentially metabolized, they spare whatever branched-chain
amino acids you have, thereby promoting muscle mass.
Reduced inflammation. Your body is
designed to have the metabolic flexibility to use both sugar and fat as
fuel sources. However, fat is preferred as it generates far fewer
reactive oxygen species and secondary free radicals when burned. So, by
eliminating sugar from your diet, you significantly decrease your risk
of chronic inflammation.
Reduced risk of cancer. I believe
cyclical ketosis is a revolutionary intervention that can significantly
lower your risk of becoming a cancer statistic, for the simple reason
that cancer cells lack the metabolic flexibility to use ketones for its
energy needs, which your regular cells can. Once your body enters
nutritional ketosis, cancer cells no longer have a readily available
source of nourishment and essentially “starve” to death before they can
become a problem.
Increased longevity. Ketosis spares
protein breakdown, which is one of the reasons you can survive a long
time without food. Much like calorie restriction (fasting), ketones also
help clear out malfunctioning immune cells13 and reduce IGF-1, which regulates growth pathways and growth genes, and plays an important role in aging and autophagy and mitophagy.
Ketone metabolism also increases the negative redox potential of your
family of NAD coenzyme redox molecules, which helps control oxidative
damage by increasing NADPH and promoting transcription of enzymes of the
antioxidant pathways though activation of FOXO3a.14
In a nutshell, ketone metabolism effectively reduces oxidative
damage, which translates into improved health and longevity. The lack of
sugar also helps explain why the ketogenic diet is associated with life
extension.
Sugar is a very potent accelerator of aging and premature death, in
part by activating two genes known as Ras and PKA, both of which are
known to accelerate aging.15
A third reason has to do with the fact that both calorie restriction
and intermittent fasting inhibit the mTOR pathway, which has been shown
to play an important role in life extension.
Weight loss:If
you’re trying to lose weight, then a ketogenic diet is one of the best
ways to do it, because it helps access your body fat so that it can be
shed. In one study,16
obese test subjects were given a low-carb ketogenic diet and a low-fat
diet. After 24 weeks, researchers noted that the low-carb group lost
more weight (9.4 kilograms; 20.7 pounds) compared to the low-fat group
(4.8 kilograms; 10.5 pounds).
Even my own body was able to feel the benefits of following a
ketogenic diet. When I first began, my weight dropped from 180 to 164
pounds, despite eating 2,500 to 3,000 calories per day. Since then, I
have increased my consumption to 3,500 to 4,000 calories just to
maintain my ideal weight.
Why Cyclical Ketosis?
A ketogenic diet and intermittent fasting both allow your body to
shift from sugar- to fat-burning — an important metabolic flexibility
that in turn promotes optimal function of all the cells and systems in
your body. And, while there’s evidence supporting either of these as
stand-alone strategies, it seems clear to me that combining them will
produce the best results overall.
As there are caveats with intermittent fasting, such as the
importance of eating healthy whole or minimally processed foods when you
do eat, there are caveats when it comes to nutritional ketosis as well.
Most people believe continuous keto is the key to success, but mounting
evidence suggests this is not the case. This is why the mitochondrial metabolic therapy (MMT) program detailed in my book, “Fat for Fuel,” stresses cyclical ketosis. There are at least two significant reasons for the pulsed approach:
• Insulin suppresses hepatic
glucogenesis, i.e., the production of glucose by your liver. When
insulin is chronically suppressed long-term, your liver starts to
compensate for the deficit by making more glucose. As a result, your
blood sugar can begin to rise even though you’re not eating any
carbohydrates.
In this situation, eating carbohydrates will actually lower your
blood sugar, as the carbs will activate insulin, which will then
suppress your liver’s production of glucose. Long-term chronic
suppression of insulin is an unhealthy metabolic state that is easily
avoidable by cycling in and out of keto. • More importantly, many of the metabolic
benefits associated with nutritional ketosis in general actually occur
during the refeeding phase. During the fasting phase, clearance of
damaged cell and cell content occurs, but the actual rejuvenation
process takes place during refeeding.
In other words, cells and tissues are rebuilt and restored to a
healthy state once your intake of net carbs increases. (The rejuvenation
that occurs during refeeding is also one of the reasons intermittent
fasting is so beneficial, as you’re cycling between feast and famine.)
How to Implement Cyclical Keto and Fasting
To reiterate, fasting and nutritional ketosis provide many of the
same benefits, and both work best when implemented in a pulsed fashion.
Together, I believe cyclical keto and intermittent fasting is a
near-unbeatable combination capable of really maximizing the health
benefits of both. While the details are provided in “Fat for Fuel,” here
is a summary of how to implement these two strategies as a cohesive
health program:
1. Implement an intermittent fasting schedule:
Eat all of your meals — either breakfast and lunch, or lunch and dinner
— within an eight-hour window each day. Fast for the remaining 16
hours. If all of this is new to you and the idea of making changes to
your diet and eating habits seems too daunting, simply start out by
eating your regular diet on this timed schedule.
Once this has become routine, move on to implement the ketogenic diet
(step 2), followed by the cyclical component (step 3). You can take
comfort in knowing that once you reach step 3, you will be able to cycle
in some of your favorite healthy carbs once again on a weekly basis.
If you want to further maximize the health benefits of fasting,
consider graduating into doing five-day, water-only fasts on a regular
basis. I do it three to four times a year. To make the process easier,
slowly work your way up to the point where you’re fasting for 20 hours a
day and eating your two meals within a span of just four hours. After a
month of doing this, pulling off a five-day water fast will not be
nearly as challenging. 2. Switch to a ketogenic diet until you can create measurable ketones: The
three-part key is to 1) restrict net carbohydrates (total carbs minus
fiber) to 20 to 50 grams per day, 2) replace the lost carbs with healthy
fats so that you’re getting anywhere from 50 to 85 percent of your
daily calories from fat, and 3) limit protein to one-half gram of
protein per pound of lean body mass. (To determine your lean body mass,
subtract your body fat percentage from 100, then multiply that
percentage by your current weight.)
Vegetables, which are loaded with fiber, can be eaten without
restrictions. The primary carb sources that need to be cut out are
grains and all forms of sugar, including high-fructose fruits. (Healthy
net carbs will be cycled back in once you’ve entered ketosis.)
Examples of healthy fat sources include avocados, coconut oil,
animal-based omega-3 from fatty fish, butter, raw nuts (macadamia and
pecans are ideal as they’re high in healthy fat while being low in
protein), seeds, olives and olive oil, grass fed animal products, MCT oil, raw cacao butter and organic pastured egg yolks. Avoid all trans fats and highly refined polyunsaturated vegetable oils.
Adding these harmful fats17
can cause more damage than excess carbs, so just because an item is
“high in fat” does not mean you should eat it. Maintain these ratios of
net carbs, fat and protein until you’ve achieved ketosis and your body
is burning fat for fuel. Keto testing strips can be used to confirm that
you’re in ketosis, defined as having blood ketones in the range of 0.5
to 3.0 mmol/L.
Keep in mind that precision is important when it comes to these
nutrient ratios. Too many net carbs will effectively prevent ketosis as
your body will use any available glucose first, since it’s a much
faster-burning fuel.
Since it’s virtually impossible to accurately estimate the amount of
fat, net carbs and protein in any given meal, make sure you have some
basic measuring and tracking tools on hand. This includes a kitchen
scale, measuring cups and a nutrient tracker (www.cronometer.com/mercola is a free, accurate nutrient tracker that is already set up for nutritional ketosis). 3. Once you’ve confirmed that you’re in ketosis, begin cycling in and out of keto
by adding higher amounts of net carbs back in, once or twice a week. As
a general recommendation, triple the amount of net carbs on these
high-carb days.
Keep in mind it can take anywhere from a couple of weeks to a few
months before your body is able to effectively burn fat again. Again,
cycling in and out of nutritional ketosis will maximize the biological
benefits of cellular regeneration and renewal, while minimizing the
potential drawbacks of continuous keto.
While higher net carb amounts are allowed once or twice a week at
this stage, I would advise you to still be mindful of what’s healthy and
what’s not. Ideally, you’d forgo potato chips and bagels, and focus on
adding in healthier alternatives such as digestive-resistant starches.
High net-carb foods such as potatoes, rice, bread and pasta all
become more digestive-resistant when they’re cooked, cooled and then
reheated, and this is one way of making such indulgences a bit
healthier. To learn more about this, see “This Simple Trick Can Minimize Damage From Unhealthy Carbs.”
No comments:
Post a Comment