CEU Article Title: Fasting Diets, the Worst Secret to Dieting Success (And More)?
Diet fads have stamped their place in history for the past several decades. From low fat, to low
sugar to Atkins to Paleo – all of these “diets” have risen to mainstream media and caught the eye of
weight watchers everywhere hoping the next diet will deliver the golden egg of getting (or staying) thin.
Magic pills, magic doses, magic eating hours all have been discussed and discarded because the truth of it all is that calories matter. Even the guy who decided to eat Twinkies and Doritos for a few weeks but stay
within a calorie deficit lost weight (albeit he probably felt like marshmallow crud). No matter how many
diet books or celebrity weight loss articles hit our Facebook newsfeeds or Pinterest boards declaring
the next new “miracle” promising to rip up your abs and shred your arms, we know the truth – calorie
restriction is the key to weight loss. Eat less, move more and you’ll lose weight. Well, lately something
“new” has entered our realm – fasting – and while in years past we’ve been taught fasting is the enemy
and will force us into starvation mode – the new question arising from all the hubbub is this, is starvation
really that bad for us? (The answer is surprising!)
*NOTE: Before we move any further along the path of discussing fasting diets, there are a few things I need to make clear. Number one, we are not registered dieticians and nothing in this article – and I mean nothing – is meant to be utilized in a capacity of providing nutritional direction, advice or prescription to your clients. Number two, the information discussed below is new – the research is new (whether or not the foundation is old)- so that means we have a long way to go before declaring anything a true “solution” to weight loss and disease. In true scientific fashion, we have great hypotheses, some preliminarily amazing results on studies with limited test subjects and without larger scale studies – we won’t know if fasting will work for everyone or anyone. With that being said, there are some fascinating new findings coming out of world-renowned universities studying longevity and disease and by all accounts, science may be helping to lead us back to
better health through the simplest of solutions: restriction.
You’ve heard the terms being thrown around training circles, intermittent fasting, the 5:2 diet, cleanses. They all break down to different methods of fasting, which in turn help individuals restrict their caloric intake. As professionals we’ve warned our clients that fasting pushes the body into “starvation mode” and that fat will be preferentially stored and will become more stubborn when trying to burn it off. We’ve relayed these words as if they were gospel. But, we may have been a little off. In fact, science is now telling us, starvation might be the key to healthier, longer lives. And it has a lot to do with suppressing a little growth hormone called IGF-1.
IGF-1 is a hormone similar in molecular structure to insulin. It plays an important role in childhood
growth and continues to have anabolic effects in adults. As fitness professionals, we seek to develop
muscle tissue and IGF-1 plays a key role in cell development – primarily skeletal muscle and nerves.
Suppressing IGF-1 seems counter-intuitive to us professionals who rely on cellular development to help
enhance our clients’ lives. However, consider the fact that IGF-1 contributes to the rapid growth of cancer
cells – and may increase the risk of Alzheimer’s disease. Those don’t sound great, do they? Sometimes, less is more (fasting has its benefits) There is more at play than blaming all the bad things that happen to our bodies on IGF-1; enzymes, nervous system interplay, brain signaling and much, much more appear to affect how our bodies react to fasting. However, a calorie restrictive lifestyle or different forms of fasting (whether alternate day, 5:2) is creating some startling and very positive effects in preliminary studies of lab mice and small-scale human studies. Here are some of the benefits researchers have found:
- Fasting benefits our cardiometabolic health (and waistlines): Researchers at Intermountian
Heart Institute at Intermountain Medical Center in Murray, Utah, found that restricting calories over an extended period of time reduced cholesterol levels in prediabetic people. After just 10-12 hours, researchers noted that the body began “scavenging for other sources of energy throughout the body pulling LDL (bad) cholesterol from fat cells to use as energy.” After 12 weeks of intermittent fasting, study participants lost weight as well as reduced cholesterol about 12 percent. With weight loss and cholesterol reduction, researchers noted that this might have helped “negate” insulin resistance (when the body becomes insulin resistant, blood sugar rises leading to diabetes). With these findings, researchers noted that fasting may be an important intervention in treating prediabetic individuals. More study is required to understand all the effects of fasting and what form of fasting would be best suited for the at-risk population. In another study done on mice, researchers underlined a potential benefit of fasting as cardioprotective:
Both IF and CR enhance cardiovascular and brain functions and improve several risk
factors for coronary artery disease and stroke including a reduction in blood pressure and
increased insulin sensitivity. Cardiovascular stress adaptation is improved and heart rate
variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents
maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction and stroke. The beneficial effects of IF and CR result from at least two mechanisms–reduced oxidative damage and increased cellular stress resistance. (Intermountain Medical Center, 2014, June 14)
- Fasting helps reduce free radicals: You know those damaging little guys that eat up your body? Free radicals do some damage, but fasting has been shown to reduce the amount of waste being generated leaving us with less, if any, metabolic garbage from our cells. As noted above:
“The beneficial effects of IF and CR result from at least two mechanisms–reduced oxidative
damage and increased cellular stress resistance.” (Mattson 2005)
- Fasting triggers regeneration of the immune system: Fascinating – while very preliminary – work is being done that is showing the potential benefit fasting may have on regeneration. Scientists found that when the body enters “starvation mode” it begins conserving energy and starts doing a little housecleaning, recycling the immune cells that are not needed or damaged. In fact, researchers found that prolonged starvation (2-4 days) forces the body to use stored glucose, fat and ketones, but also break down a portion of white blood cells. According to researchers, when white blood cells are reduced, this triggers “stem cell-based regeneration of the new immune system cells.”
“PKA [an enzyme linked to extending longevity] is the key gene that needs to shut
down in order for these stem cells to switch into regeneration mode. It gives the ‘okay’
for stem cells to go ahead and start proliferating and rebuild the entire system.”
(University of Southern California, 2014, June 5)
- Fasting may speed recovery: a study investigating the effects of fasting on muscle damage and recovery found that while fasting didn’t completely negate training induced muscle damage, the fasting group showed less signs of fatigue, oxidative stress and inflammation. (Mattson 2005, Antoni 2014)
- Fasting helps protect (and maybe even regenerate) the brain: Several studies are investigating the power of fasting on neurological degeneration. In several studies reported, calorie restriction and intermittent fasting created a protective response that safeguarded neurons against factors (genetic and environmental – like stress or free radicals) that would usually be a part of the aging process. One such study done on mice with neurodegenerative disorders (like Alzheimer’s Disease) found that fasting increased production of brain-derived neurotrophic factor (a protein that acts like a protector of neurons and even encourages the growth of new neurons), which helps neurons in the brain resist dysfunction and degeneration. Even more exciting is the potential for the brain to repair itself. Recent findings suggest that fasting and/or calorie restriction may provide the right internal environment to allow for the brain to resist disease and create new nerve cells. Also note – this outcome has been seen with exercise as well – so while it’s not new per se, it’s exciting that a dietary intervention such as fasting and/or calorie restriction can have such a similar effect. (Martin 2006, Mattson 2005, Anson 2003)
Popular Fasting Protocols
With so much ado about fasting circling the gyms right now, it’s just a matter of time before a client asks
you about a fasting diet. There are three main fasting protocols you should understand and be able to
answer questions about since they are the most popular right now: Alternate day fasting, The 5:2 diet, and
Lean Gains. These protocols are more involved than the information I am going to summarize and I must
remind you that it’s a very fine (and dangerous) line to cross when providing nutrition advice. So please
do not read these summaries and advise your clients to start one of these fasting protocols – that wouldn’t
Alternate Day Fasting (& Eat-Stop-Eat)
This fasting protocol is just as it sounds. One day a person eats as they normally would without
regard to macronutrients or calories ingested. The next day, the individual would reduce her calories
dramatically, eating one small meal (usually advised to be eaten mid-day) that would be less than 500
calories for men, 400 calories for women. This cycle repeats with no clear ending. There are no recommended
time frames to end the program or advisory warnings explaining any dangers of prolonged
program implementation. The science has yet to catch up on whether or not this program has long-term
ill effects. In addition, a more strict and possibly more authentic “fasting” protocol has been popularized
in Brad Pilon’s book Eat-Stop-Eat. In summary, his plan allows you to eat normally for 24 hours and then
fast for 24 hours, this means not eating a single scrap of food (eg. finish eating at 8 PM on a Sunday night
and not eat again until 8PM on a Monday night). The link above offers the ability to learn more about his
book, however, there is no scientific evidence that his plan is the hook on which you should hang your
5:2 Fasting Diet
This fasting protocol keeps it pretty simple as well. The 5:2 diet asks participants to fast for two
days – not consecutively – and eat “normally” for 5 days. On the fasting days (for example Monday and
Thursday) men are advised to eat 500- 600 calories and women 400- 500 calories. These meals can be
broken into several small meals throughout the day (as they advise on their site) and they even have
recipe ideas for those implementing the protocol. Also note – the fasts are not 24-hour fasts, but 36 hours
(eg. Start the fast at 6PM on a Sunday night and you can break the fast at 6 AM the following Tuesday
morning). This diet was popularized by Dr. Mosley who created the documentary about fasting for BBC
America, “Eat, Fast & Live Longer.” This program was maintained for 5 weeks in the documentary, but
information on their site suggests on-going implementation for the effects to last. Again, research has yet
to catch up on any potential long-term ill effects of this eating protocol.
Lean Gains (and others like Warrior Diet)
This may be the most common fasting protocol being talked about in gyms as it has been around
the longest in our fitness circles. Many might know of this diet as Lean Gains created by Martin Berkhan.
This is the most popular daily fasting protocol that asks participants to create a daily fasting window –
16 hours – and that allows for a small window of time to eat, roughly 8 hours. While he shows plenty of
scientific evidence for his protocol, again, we won’t understand the true merits of his Lean Gains methodology (or any of the above methods for that matter) until science has been given time to catch up. Other fasting window protocols – for example the Warrior Diet – provide short eating windows (4 hours for
warriors) and discuss evidence similar to Berkhan, however the twist with the Warrior Diet is the 4-hour
window is at night – suggesting humans are hard-wired nocturnal eaters.
Empirical evidence and clinical evidence do show that fasting protocols will provide benefits,
however the “best” protocol has yet to be deciphered and for whom the protocols work best. Since we are
all individuals – with busy lives and unique challenges – no one protocol may fit all dieters. I advise you
to read more about each protocol, since I hardly did any of them any justice, and learn the ins and outs of
each, being better equipped to answer the many questions your clients will have about fasting diets.
Let’s sum it up!
Fasting isn’t new. It isn’t ground breaking. Heck, our ancestors did it all the time (especially if they
were a bad aim or decidedly slow, like myself). But in modern times, what if this style of eating could
help clients lose weight and reduce their chance of disease? Since many clients enter your realm with
excess weight, there is a good chance many may be tippy-toeing towards diabetes (pre-diabetics), high
cholesterol or high blood pressure – especially since these are often co-morbidities of excess fat. In fact,
you probably have a few clients who have done more than tiptoe over the line; many sprinted over it and
had no idea until the damage was done. While future research is needed, science is finding that restricted
dietary patterns like prolonged fasting or intermittent fasting may not only help reduce weight and
waistlines; it might just help increase lifespan and reduce disease. The potential of this form of dietary
intervention could be priceless (and cost you nothing but a day’s worth of calories).
1. Rona Antoni, Kelly L. Johnston, Adam L. Collins and M. Denise Robertson (2014),
“The Effects of Intermittent Energy Restriction on Indices of Cardiometabolic
Health,” Research in Endocrinology, Vol. 2014 (2014), Article ID 459119, DOI:
2. Krista Varady, et al. “Alternate Day Fasting for Weight Loss in Normal Weight and Overweight
Subjects: a Randomized Controlled Trial.” Nutrition Journal 2013, 12:146.
3. Mosley, M. “Eat, Fast & Live Longer.” BBC America. (2012).
4. Dannecker, E. A., et al., “The Effect of Fasting on Indicators of Muscle Damage.” Exp Gerontol
48, no. 10 (2013): 1101-6.
5. Antoni, R. et al., “The Effects of Intermittent Energy Restriction on Indices of Cardiometabolic
Health”. Research in Endocrineology Vol 2014 (2014), 24 pages.
6. Intermountain Medical Center. (2014, June 14). Fasting Reduces Cholesterol Levels in
Prediabetic People Over Extended Period of Time, New Research Finds. ScienceDaily.
Retrieved December 30, 2014 from www.sciencedaily.com/releases/
2014/06/140614150142.htm7. University of Southern California. (2014, June 5). Fasting Triggers Stem Cell Regeneration
of Damaged, Old Immune System. ScienceDaily. Retrieved December 30, 2014 from
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MP. Intermittent Fasting Dissociates Beneficial Effects of Dietary Restriction on Glucose
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Me Run. Brain Res. 2000 Dec 15;886(1-2):47-53.