Stephen
N Kreitzman,
ABSTRACT
Ann
Glycogen
fat cells in hydrated
with potassium
(0.45
(TBK)
changes
reflect
glycogen
distort
changes
laden
the
in the
form (three
to four
mmol
K/g glycogen).
storage.
due
after
is stored
Kalman
of
body
to glycogen
glycogen
on weight
exaggerated
influence
during
if carbohydrate
for weight
nitrogen
losses
1992;56:292S-3S.
measured
The
with
control
dieting
are
can
TBK
in 1 1 subof water-
occurs,
and
The
Am
Foundation
Eleven
The
and
fat, and
(405-kcal)
the
of
J C/in
Nutr
maintenance
Very-low-calorie
diet,
fat-free
mass, recidivism,
VLCD,
glycogen,
dieting
total
The
utilization
ofglycogen
a significant
effect
on the
ofrecidivism
after
a period
weight
with
degree
required
to reduce
(1 800 kcal/lb)
due
to both
stores
is far less than
the
carbohydrate
difference
and,
during
can
fat lost.
The
glycogen
as fuel
the
large
be disheartening
can also lead
losses
a modest
weight
provide
eating
energy
losses.
each
depleted
estimation
early
weight
of water
weight
to achieve
as-
would
recidivism
upon
Cambridge,
10-week
UK.
fifth
day
VLCD
TBK
ofthe
g carbohydrate,
59.3
g
days before
starting
the 1700-U
Diet, Cambridge
Nutrition
Ltd.
body
potassium
the whole-body
total
using
on the
(TBK)
counter
was again
Cambridge
was measured
in
at Addenbrookes
assessed
at the same
Diet
and
at the end
of
program.
Results
first
are shown
in Tables
4 d of VLCD
of
1 and 2. Potassium
180
mmol
of dieting
estimate
glycogen
reflects
of 400
storage
primarily
that
g stored
in healthy
glycogen
people.
changes
compare
mmol lost in the subsequent
10 weeks
that the vast majority
of the potassium
Because
glycogen
is associated
with
potassium
gram
ofglycogen
and
in the
earliest
phases
during
diet
(VLCD)
the
first
should
of any
days
primarily
of
in the
ratio
with
during
only
104
of dieting.
It is assumed
lost in these initial days
bound
up with
matches
glycogen.
other
The
estimates
of
considerable
(0.45
mmol
potassium
is bound
K/g glycogcn)(
up with the hydrated
1), the loss of400
g glycogen
of 0.45
glycogen
is necessarily
diet.
depletion
The
a ketogenic
reflect
I
of
very-lowthe
labile
gly-
cogen.
292S
201.7
food
trial.
Discussion
significant
storage
rapid
contained
were
ofearly
weight
of the ability
of
ofglycogen
loss and
diet
UK),
subject
Results
will be regained
ease
exercise
K to each
potassium
calorie
this
Howard
consent.
a diet.
Olycogen
mmol
or even
Quantitative
into
which
the
the
deficits,
therefore,
the illusion
of sig-
to a dieter. The apparent
to unrealistic
expectations
restriction
insight
after
with
the
of fat versus
amounts
committees
and
deficit
(3400 U/kg)
(3500 kcal/lb)
contributions
ethical
University,
can
and
energy
fat (32 2 17 kJ/kg)
more,
case
lost
The
sociated
with storage
glycogen.
Small energy
early in a weight-reduction
diet, can produce
nificant
reduction
weight
ofdieting.
in energy
even
weight
apparent
by the
Swansea
Olycogen
amount
was calculated
by taking the difference
in
TBK between
predict and day 5 of VLCD, expressed
as mrnol
K. Because 0.45 mmol K represents
1 g glycogen,
total glycogen
loss is represented
by mmol TBK/O.45.
Introduction
have
accepted
67.8 g protein.
Four
VLCD
(Cambridge
Norwich,
facility
WORDS
potassium,
was
University,
Research.
All subjects
gave informed
female
subjects
of varying
body
mass
Hospital,
KEY
body
protocol
indexes
placed on an identical,
standardized
6694-U
(1600-kcal/d)
program
for I 1 days before an extensive
weight-reduction
process,
overestimation
discussed.
study
of Cambridge
primarily
the dieting
loading
programs
Methods
potassium
dieting.
were
a VLCD.
and
associated
glycogen
during
fluctuations
regain
implications
from
composition
with
muscles,
(VLCDS)
released
mobilization
4 d dieting
liver,
diets
Potassium
F Szaz
parts water)
Total body
early in very-low-calorie
estimates
jects
Y Coxon,
loss, excessive
Am
J C/in
Nuir
1992:56:2925-35.
From
Howard
Foundation
Cambridge,
UK.
2 Supported
by the Howard
Research
Foundation,
and Cambridge
UK.
Address reprint requests to SN Kreitzman,
Howard
search, Unit 254 Science Park, Milton Road, Cambridge,
3
Printed
in USA.
©
1992
American
University,
Society
Foundation
ReUK CB4 4WE.
for Clinical
Nutrition
Downloaded from ajcn.nutrition.org at PENNSYLVANIA STATE UNIV PATERNO LIBRARY on September 12, 2016
Glycogen storage: illusions of easy weight
weight regain, and distortions in estimates
of body composition3
GLYCOGEN
will
result
in the
composition,
mass
(FFM)
zation
release
of 3.5
stores
variability,
which
losses
or gains
three
to four
not
readily
could
water,
be associated
certainly
Bergstrom
depleted
before
for 3 d. After
sixfold
higher,
cogen
repletion,
TABLE
2
Individual
differences
in estimated
change after 4 d ofthe VLCD
as a
as much
with
an additional
as 5 kg weight
fat loss.
ofany
weight-loss
losses
before
before
comparing
efassessing
recidivism,
dieters
for lack
that
normal
a high-carbohydrate
than
associated
As glycogen
change
any
for these
methods,
with
diet
twice
water,
stores
control.
glycogen
can
low-carbohydrate
the glycogen
normal.
This
could
follow
arc
program,
ofpostdiet
muscle
Subject
Weight on
day of
first TBK
be
diet
stored
excessive
inappropriate
TABLE
I
Average total body potassium
(TBK) and estimated
glycogen storage
values of dieting subjects before the very-low-calorie
diet (VLCD),
after 4 d ofthe VLCD. and after 10 wk ofthe VLCD
rose
gly-
1
2
3
4
5
6
7
8
9
10
11
12
.±SD
Weight
after
4 d VLCD
storage
and initial
Weight loss
after
4 d VLCD
weight
Estimated
glycogen
storage
kg
kg
g
87.6
90.4
89.8
75.2
108.2
65.6
84.4
107.6
78.8
83.0
104.0
95.4
85.6
86.0
82.4
71.8
105.2
62.5
80.2
100.9
75.4
80.7
98.0
89.7
2.0
4.4
7.4
3.4
3.0
3.1
4.2
6.7
3.4
2.3
6.0
5.7
333
426
520
333
520
373
1066
80
146
333
240
613
89.2±
refeeding
after
weight
regain.
glycogen
kg
Glycogen
conclusion
one-third
to more
utili-
of 400 g are
intersubject
1 kg glycogen.
(2) to be associated
criticizing
with
The
be misinterpreted
reached
et al (3) demonstrated
to about
potassium.
therefore
so that
with
after
of body
of fat-free
FFM.
are reported
replenished
Studies
kilogram
losses by this subject
group
not obscure
the considerable
it is necessary
to account
fectiveness
of weight-loss
and
60 mmol
K.
each
293S
13.1
84.8±
12.3
dieting,
leading
to
4.3±
rapid
and
1.8
excessive
415 ±256
nonfat
U
References
TBK
Before diet
On day 5 ofdiet
Lost after 4 d diet
Lost between days
Estimated
glycogen
5 and 70
storage
3300
3 120
180
104
400
mmol
mmol
mmol
mmol
g
1. Patrick I. Assessment
ofbody potassium
stores. Kidney Int l977;l I:
476-90.
2. Olsson K. Saltin B. Variation
in total body water with muscle glycogen changes in man. Acta Physiol Scand 1970:80: 1 1-8.
3. Bergstrom
J, Hermansen
L. Hultman
E. Diet, muscle glycogen and
physical performance.
Acta Physiol Scand 1967:71:140-50.
Downloaded from ajcn.nutrition.org at PENNSYLVANIA STATE UNIV PATERNO LIBRARY on September 12, 2016
might
with
in one subject
parts
mmol
that
kg nitrogen-rich
The mean
glycogen
reasonable.
This should
200
>
assume
is associated
of glycogen
loss
of
K40,
using
STORAGE