Calorie Restriction For Life Extension:
What They Didn't Tell You On Oprah
On a recent episode of the Oprah show, one of the guests was a 51 year old man with the heart of a 20 year old. He's been following a calorie restriction plan and they said he might be one of the first people to
reach 120 years old by following this plan. There have been stories both in the lay press and scientific press about calorie restriction for years and it has been a frequent talk show topic on other many other TV shows. However, before you cut your calories in half in hopes
of adding another decade onto your life, you'd better get the other half of the story they didn't talk about on Oprah.
I’ve seen a lot of strange things in the health field, and
although calorie restriction (CR) is the subject of serious and legitimate scientific study, I consider CR to be one of those strange
things. Of course, that's because I choose a different lifestyle - the muscle-friendly Burn The fat, Feed The Muscle lifestyle - but there's more than one reason why I'm not a CR advocate:
Hunger while dieting is almost always a challenge. There's some hunger even with conservative calorie deficits of 15-20% under
maintenance. Prolonged hunger is one of the biggest reasons people fall off the weight loss diet wagon because it's unpleasant and
difficult to resist. This is why pharmaceutical and supplement companies spend millions of dollars on researching, developing and
marketing appetite suppressants. Yet CR advocates put themselves through 30-50% calorie restriction on a daily basis as a way of life in
the hopes of extending life span or health.
People who practice CR follow a low-calorie lifestyle, but technically, they are not in a chronic 30% calorie deficit.
Living with a calorie deficit would definitely be impossible!
What happens is their metabolism gets very slow (that's part of the idea behind CR; if you slow down your
metabolism, you allegedly slow down aging). So a 6 foot tall man who would normally require nearly 3,000 calories to maintain his weight,
might eventually reach an energy balance at only 1800 or 1900 calories. This is not just due to a "starvation mode" phenomenon, that's only part of it. It's primarily
because he loses weight until he is very thin and his smaller body doesn't need many calories any more.
Does caloric restriction really extend lifespan?
The biological mechanisms of lifespan extension through calorie
restriction are not fully understood, but researchers say it may
involve alterations in energy metabolism
(as mentioned above), reduced oxidative damage, improvements in insulin
sensitivity, reduction of glycation, modulation of protein metabolism,
downregulation of pro-inflammatory genes and functional changes in both neuroendocrine and autonomic nervous systems.
Mouse studies on CR go back as far as 1935 and monkey studies began in
the late 1980's. So far the results are clear on one thing:
caloric restriction does increase lifespan in rodents and other lower
species (yeast, worms and flies). Studies suggest the life of the
laboratory rat is 25% longer with CR (even longer with aggressive CR).
Primate studies are still underway and humans have been experimenting
with CR for some time. In primates and humans, biomarkers of aging show
signs of slower aging with CR. This makes many proponents talk about
this CR as if it were a sure-thing, already proven through double-blind randomized clinical human trials.
The truth is, at the time this is being written, there is NO direct experimental evidence that you will
live longer from practicing CR. Due to the length of human lifespans,
we will not have the necessary data for at least another generation and
perhaps multiple generations. Even then, it will still be highly
speculative whether CR will extend human life at all and if so how
much. We can only estimate. I've seen guesses in the
scientific literature ranging from 3 to 13 years, if CR is practiced for an entire adult lifetime.
Jay Phelan, a biologist at UCLA is skeptical. He says the potential
life extension is on the lower end of that range and the increase is so
small that it's not worth the semi-starvation:
"There is no current evidence that lifelong caloric
restriction leads to increased lifespan in primates. It's
certainly tantalizing that things like blood pressure or heart rate
look as though they are a lot healthier and I believe they are. Whether
or not this translates to a significantly increased lifespan, I
don't know. I predict that it doesn't."
Additional information from Jay Phelan, at the Lifeboat Foundation.
I don't quibble qualitatively with their results. Yes, it
will increase lifespan, but it will not increase it by 50% or 60%, it
won't increase it by 20% or 10%, it might increase it by 2%.
So if you tell me that I have to do something horrible for every day of
my life for a 2% benefit - for an extra year of life - I say no thanks.”
Is prolonged caloric restriction unhealthy?
When caloric restriction is practiced with optimal nutrition (CRON), it
is not inherently unhealthy. Actually, it appears the reverse is true.
First, the weight loss that comes with the low calories produces
improvements in the health markers, as you would expect. Second, the
meticulous choice of food from CRON practitioners, where they pick high
nutrient foods and avoid empty calories means that they are making
healthy food choices. Third, advocates say that the CR itself improves
health. I wonder, however, how much does CR improve health independent
of the weight loss and the optimal nutrition?
By losing fat and maintaining an ideal body composition (the fat to
muscle ratio) and eating high nutrient density foods, I propose that
even at a more normal caloric intake, you will get very significant
health and longevity benefits. I also propose that gaining muscle in a
natural way (no steroids) will increase your quality of life today and
as you get older.
Aside from the fact that we are not lab rats, the truth is, none of us
knows when our day will come. We could get plucked off this physical
plane at any moment and have no control over how it happens. My belief
is that we should make our lifestyle decisions based on quality of
life, not just quantity of life. That includes our quality of life
today as well as our anticipated quality of life when we are older.
Maybe we ought to be focusing more on “health span”
than life span.
Downsides
of calorie
restriction for life extension
One fact about calorie restriction that they often don't
mention on these talk shows is that the benefits of CR decline if you
start CR at a later age. This was discussed in a research paper from
the Journal of Nutrition called, “Starving for life: what
animal studies can and cannot tell us about the use of caloric
restriction to prolong human lifespan.” The author of the
paper, John Speakman from the School of Biological Sciences at the University of Aberdeen in Scotland, said that the later in life you
begin to practice CR, the less of an increase in lifespan you will
achieve. Even if the CR proponents are right, if you started in your
late 40's or mid 50's for example, the benefit
would be minimal. If you started in your 60's the effect
would be almost nonexistent. Essentially, you have to “starve
for life” to get the benefits.
While some CR proponents claim that they aren’t hungry and
they cite studies suggesting that hunger decreases during starvation,
Speakman and other researchers say that hunger remains a big problem
during CR - especially in today’s modern society where we are
surrounded with convenience food and numerous eating cues - and that
alone makes CR impractical:
"Neuroendocrine profiles support the idea that animals under
CR are continuously hungry. The feasibility of restricting intake in
humans for many decades is questionable."
Let’s suppose for a moment that CR is totally legit and the
claims are true. Many of the proposed benefits of CR come at the
expense of what many of us are trying to do here: gain and maintain
lean body mass. One spokesman for CR is 6 feet tall and 130 pounds.
Another poster boy for CR is 6 foot tall and 115 lbs. Measurements of
rodents under CR not only show large reductions in skeletal muscle but
also bone mass.
I am not suggesting that these CR practitioners are anorexic, a concern
that has been raised about CR when practiced aggressively. However,
they are losing large amounts of fat-free tissue and that is plainly
obvious for all to see when you look at their bony physiques. I am not
imposing my body standards on others, but 115 to 130 lbs at 6 foot tall
is underweight for a man by any standard. Furthermore, researchers say
that at the body mass indices sustained by most voluntary CR
practitioners, we would expect females to become amenorrheic.
“One thing that is completely incompatible with a CR
lifestyle is reproduction” says Speakman.
With that kind of atrophy, I have to wonder what their quality of life
will be like in old age. While many people struggle with body fat for
most of their adult lives, I’m sure almost everyone knows an
elderly person who wrestles with the opposite problem: they are
seriously underweight and they struggle to eat enough and maintain lean
body mass.
My grandmother, before she passed away, was under 80 lbs. We could not
get her to eat. She was weak and very frail. I have reported many times
about the research showing how most overweight people under estimate
calorie intake and eat more than they think or admit. In elder care
homes, the research has often showed the opposite - the patients over
estimate how much they eat. They swear they are eating enough, but they
arent and they keep losing dangerous amounts of weight. With
underweight, atrophied seniors, weakness means less functionality and
lower quality of life and a fall can mean more than broken bones, it
can be life-threatening.
Life
extension with more
muscle
While there is a commonality between CRON and the way I recommend
eating (high nutrient density, low calorie density foods), in most
regards, CR is the opposite of my approach. In my Burn
The Fat, Feed The Muscle program, we go for a higher energy
flux nutrition program, which means that because we are weight training
and doing cardio and leading a very active lifestyle, we get to eat
more. Because we are so active and well-trained, the eating more does
not have a negative effect as it would on a sedentary person, who might
get sick and fat from the additional calories. We active folks take
those calories, burn them for energy, partition them into lean muscle
tissue and we enjoy a faster metabolism and extremely high quality of
life.
As a bodybuilder, CR is not compatible with my priorities, but
hypothetically speaking, if I were to practice a lower calorie
lifestyle, I wouldn’t follow an aggressive CR approach.
I’d probably do as the Okinawans do. They have a very simple
philosophy: hari hachi bu:
eat until you are only 80% full. While this does not mean there is a
carefully measured 20% calorie deficit, it’s consistent with
what we practice in the Burn
The Fat, Feed The Muscle lifestyle for a fat loss phase, and
avoiding overeating is certainly a smart way to avoid obesity and
health problems. Incidentally, the Okinawans eat about 40% less than
Americans, and 11% less than they should, according to standard caloric
intake guidelines, and they live 4 years longer than Americans.
If someone is being “sold” on CR by an enthusiastic
CR spokesperson, or simply curious after watching the latest TV talk
show (where they are looking for controversial stories), it’s
important to know that there is more than one side to the story. If you
carefully read the entire body of research on CR, you will see that the
experts are split right down the middle in their opinions about whether
CR will really work. CR for humans remains highly controversial and
there are no guarantees that this will extend your life.
Researchers
at the
National Institutes of Health in Baltimore, MD put it this way:
“Because it is unlikely that an experimental study will ever
be designed to address this question in humans, we respond that
“we think we will never know for sure.” We suggest
that debate of this question is clearly an academic exercise.”
In closing, let me go back to one of the original questions I was
asked: “Can the BFFM food plan also be thought as a longevity
lifestyle, but with more muscle mass?” Absolutely beautifully
said! That’s precisely what Burn
The Fat, Feed The Muscle is.
I believe that by making healthy food choices but doing so at a higher
level of calorie intake and expenditure, that we can fend off
sarcopenia - the age related decline in muscle mass that debilitates
many seniors - while enjoying a more muscular physique, greater
strength, and a less restrictive lifestyle. Most gerontologists agree -
by making simple lifestyle changes that include strength training and
good nutrition, you can easily turn back the biological clock 10 years
without going hungry.
For more information about Burn
The Fat, Feed The Muscle, the “longevity lifestyle
with more muscle”, visit: www.BurnTheFat.com
Train hard and expect success,
Tom Venuto
Fat Loss
Coach
www.BurnTheFat.com
About the
Author:
Tom Venuto is a fat loss expert, lifetime natural (steroid-free)
bodybuilder, independent nutrition researcher, freelance writer, and
author of the #1 best selling diet e-book, Burn
The Fat, Feed The Muscle: Fat-Burning Secrets of The
World’s Best Bodybuilders & Fitness Models (e-book)
which teaches you how to get lean without drugs or supplements using
secrets of the world's best bodybuilders and fitness models. Learn how
to get rid of stubborn fat and increase your metabolism by visiting: www.burnthefat.com
References:
Hunger
does not diminish
over time in mice under protracted caloric restriction. Hambly C,
Mercer JG, Speakman JR.Rejuvenation Res. 2007 Dec;10(4):533-42.Aberdeen
Centre for Energy Regulation and Obesity (ACERO), Rowett Research
Institute, Bucksburn, Aberdeen, Scotland, United Kingdom.
Starving
for life: what
animal studies can and cannot tell us about the use of caloric
restriction to prolong human lifespan.Speakman JR, Hambly C. J Nutr.
2007 Apr;137(4):1078-86. School of Biological Sciences, University of
Aberdeen, Aberdeen AB24 2TZ, Scotland, UK.
Can
dietary restriction
increase longevity in all species, particularly in human beings?
Introduction to a debate among experts. Le Bourg E, Rattan SI.
Biogerontology. 2006 Jun;7(3):123-5.
The
potential for
dietary restriction to increase longevity in humans: extrapolation from
monkey studies. Ingram DK, Roth GS, Lane MA, Ottinger MA, Zou S, de
Cabo R, Mattison JA.Biogerontology. 2006 Jun;7(3):143-8. Laboratory of
Experimental Gerontology, Intramural Research Program, National
Institute on Aging, National Institutes of Health, 5600 Nathan Shock
Drive, Baltimore, MD 21224, USA.
Caloric
restriction in
humans: potential pitfalls and health concerns. Dirks AJ, Leeuwenburgh
C.Mech Ageing Dev. 2006 Jan;127(1):1-7. Epub 2005 Oct 13, Wingate
University, School of Pharmacy, 316 N. Main Street, Wingate, NC 28174,
USA.
Caloric
restriction and
human longevity: what can we learn from the Okinawans? D. Craig
Willcox, Bradley J. Willcox Hidemi Todoriki. Biogerontology (2006) 7:
173—177
Endocrine
alterations in
response to calorie restriction in humans. Mol Cell Endocrinol. 2009
Feb 5;299(1):129-36. Epub 2008 Oct 21. Redman LM, Ravussin E.
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge,
LA 70808, United States.
Caloric
restriction in
the presence of attractive food cues: external cues, eating, and
weight. Polivy J, Herman CP, Coelho JS.Physiol Behav. 2008 Aug
6;94(5):729-33. Epub 2008 Apr 13. University of Toronto, Canada.
Life
Extension by
Calorie Restriction in Humans. Everitt AV, Le Couteur DG.Ann N Y Acad
Sci. 2007 Aug 23, Centre for Education and Research on Ageing,
University of Sydney, Concord, New South Wales, Australia.
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