Supporters of the Atkins Diet claim that
a low carbohydrate diet is a safe and
effective method for losing weight. This
article evaluates the low carbohydrate
diet and specifically the claims made
about ketosis.
<h4>The Low Carb-Ketosis Link</h4>
By severely limiting carbohydrates in
your diet, the main energy source used
by your body, glucose, drops to low levels.
In return, insulin levels also drop. With
low glucose and low insulin levels, the
body turns to alternative sources of energy.
Because of a significant change in your
body's chemistry when on the Atkins Diet,
certain metabolic pathways are turned
"on" that are normally not "on" or run
at very low levels. One such pathway involves
the breakdown of fat, called Beta-Oxidation
of Fats.
Now, normally fats are broken down to
produce energy when your body senses a
need. But in the context of a low Carb
diet, the normal breakdown pathway of
fats is altered and an alternative pathway
kicks in. This alternative pathway produces
what are called ketone bodies.
Ketosis is the term used to describe
when ketone bodies are circulating in
your bloodstream. The ketone bodies can
be used as alternative sources of energy
by, most importantly, your brain.
In case you might be curious, the three
ketone bodies produced by this alternative
pathway for breaking down fat are acetoacetate,
beta-hydroxybutyrate, and acetone. These
ketone bodies are formed in your liver
and then are transported to other tissues,
mainly the brain. In your brain, they
are converted back to a form that can
provide direct energy during times of
starvation.
Here is the whole process...
<ol><li>Atkins Diet lowers
glucose and insulin (the body's main energy
source)
<li>Alternative pathways are turned
"on" to provide energy
<li>One alternative pathway breaks
down fat and produces ketone bodies
<li>Ketone bodies represent the
state called ketosis
<li>The brain uses ketone bodies
as an alternative source of energy</li></ol>
So, the Atkins Diet (and any low Carb
diet) produces a low energy state (low
glucose) that causes the breakdown fat
using an alternative pathway that leads
to the development of ketosis.
So far it sounds pretty good. By limiting
Carbs in your diet, you can essentially
force your body into breaking down stored
fat, the very thing you need to get rid
of to lose weight.
But there are problems...
<h4>Atkins Diet and Toxicity</h4>
Ketone bodies are toxic. Many supporters
of low Carb diets claim that ketosis is
safe. They state that they are natural
byproducts of fat breakdown and even babies
have high levels of circulating ketone
bodies.
First, they are not natural by-products
of fat metabolism. The normal beta-oxidation
of fats does produce ketone bodies but
these are incorporated into the normal
cycle of energy production, called the
Krebs cycle. When ketone bodies are circulating
in your bloodstream, it signals an abnormal
physiologic state, called starvation.
They are not incorporated into the normal
energy cycle, the Krebs cycle, and spill
into the bloodstream.
Just because your body has the ability
to transport ketone bodies to certain
tissues and then use them for energy,
does not make it a normal process. It
is an alternative pathway that turns "on"
only when your body is faced with depleted
levels of the main energy source, glucose.
Secondly, babies are not small adults.
A baby's liver and brain tissue are made
up of different chemicals and pathways,
specifically geared to handle the high
fat diet coming from mother's milk. These
pathways change as a baby grows and starts
to eat other foods. Eventually, the normal
adult pathways are set up and the infantile
chemistry used as evidence to support
the safety of ketosis, stop working.
But this is not even related to the fact
that ketone bodies are toxic. In medicine,
the three ketone bodies mentioned above
are classified as toxic acidic chemicals.
At high levels, they can cause your blood
to become too acidic, a disease state
called ketoacidosis.
Granted, this is rare because most of
the ketone bodies will be used by the
brain as an energy source. Ketoacidosis
is usually seen in type 1 diabetics. It
is a medical emergency.
So, is ketosis dangerous to your body?
Yes and no. Yes, ketosis represents a
state of starvation. Losing weight when
the body thinks you're starving is the
best way to guarantee weight regain. The
weight will come back and come back as
fat. No, ketosis will not cause ketoacidosis
in non-diabetics. And as long as you have
a large storage of fat, your brain will
not starve for energy.
<h4>The Final Verdict</h4>
<ol><li>As an alternative
physiologic state, ketosis is not dangerous,
assuming the levels of ketone bodies do
not increase to acidic levels.
<li>As a diet plan, ketogenic diets
are not recommended because of the state
of starvation they create. Your metabolism
will eventually slow down setting you
up for weight regain in the near the future.
<li>Ketogenic diets, like the Atkins
Diet, may also be dangerous not because
they cause ketosis, but because they promote
high protein and fat intake. High protein
diets, unless you're body building, increases
urea production and can damage the kidneys.
Supporters claim that this just doesn't
happen, reporting that no kidney damage
has occurred to the millions of dieters
on Atkins Diet or other ketogenic diets.
However, it is well known that microscopic
damage can occur to the kidneys effecting
their ability to filter the blood. But
clinical signs of this damage may take
several years to manifest. Chronic renal
insufficiency is a concern for ketogenic
dieters, which may cause problems in the
years to come.</li></ol>
<h4>Conclusion</h4>
Atkins Diet and other ketogenic diets
(low Carb) can be safe and effective in
causing weight loss. However, I recommend
keeping ketosis to a minimum and keep
your carbohydrate intake above 50 grams
a day. Don't follow the suggestions for
reaching an "induction" phase. It's not
necessary to turn "on" the alternative
pathways described above and burn fat.
Remember, healthy weight loss is to burn
fat and fat only. But it also involves
keeping your rate of weight loss around
2-3 pounds/week. The induction phase promoted
by the Atkins Diet can result in a rate
of weight loss far greater than 2-3 pounds/week.
It may sound good to you now, but how
does gaining it all back as fat sound?
Because that will happen if you lose weight
too fast.
For more information on ways to experience
healthy weight loss, visit
www.weight-loss-professional.com/articles
To Healthy Living!
Dr. Michael A. Smith
Chief Medical Consultant
Diet Basics Website
About the Author
Dr. Smith is the Chief Medical Consultant
for Diet Basics, a content based weight
loss web site dedicated to all dieters
fighting to lose weight. Please visit
his site at
www.weight-loss-professional.com/articles
Just one visit and you'll be hooked.