Eating less does not result in weight loss

On Wed, 08 Oct 2003 18:22:19 -0700, Michael Snyder wrote:
Nope. You may be a physicist, but why are you claiming that bodies
violate the laws of thermodynamics,

I *explicitly* did not claim that. To apply the laws of thermodynamics,
you have to consider ALL of the inputs and outputs. Food in and
energy-expended out is not even remotely a full accounting.

Feel free to name other significant problems.

You can excrete food if you have digestive problems, but typically
the energy density of food has already been calibrated for human
biology as opposed to total potential energy. These syndromes
might explain somebody who is abnormally thin, but not abnormally
fat.

Humans are not photosynthetic, nor can they extract useful
energy from magnetic fields.

RLW writes:

And other forms of energy.

Well, organized kinetic energy (movement), disorganized kinetic energy
(heat), and electromagnetic radiation. Am I leaving anything out?

I feel like I'm banging my head on a brick wall.

It can try the patience, that's for sure. But some people do come to
understand the basic principles, if they are truly and objectively
interested in weight loss, so it isn't as useless as it might seem.
Remember, lots of people read the posts, even though they might not post
themselves.

Different macronutrients have different amounts of energy
intrinsically within their chemical bonds.

That's why a gram of fat has more calories than a gram of sugar.

Both fat and carbohydrate can be metabolised completely to
water and carbon dioxide, so I can see why you'd think calories from them
would be identical.

A calorie is a calorie.

However, when carbohydrate is converted and stored in
adipose tissue, more energy is lost than when fat is stored.

The usual calorie equivalents for different macronutrients take this
overhead into account. That's why fat is often assigned 7 kcal per
gram, even though it actually contains 9 kcal per gram. The 2 kcal
difference is the overhead of converting fat to and from fat.

I tried to find exact amounts of energy lost for these reactions in my
undergrad biochem textbook, but they didn't give any.

I recall about 2 kcal per gram for fat, total. I don't recall the
figures for other macronutrients. The only figures I keep in mind are
the net figures, after adjustment for conversion overhead.

If you can cite some solid evidence to show that 100 calories of fat and 100
calories of protein or carbohydrate are stored as the same amount of adipose
tissue in the human body, I'd be interested in seeing it and would recant my
position immediately.

I've seen no evidence to indicate otherwise, so the burden of proof is
upon you.

In the meantime, I shall say that I think the most effective way to lose
weight is to cut caloric intake.

Correct. And it doesn't matter what form the calories take. All that
matters is their total number.

From my own experiences, exercise by itself while maintaining
a contant caloric intake did practically nothing to change my weight.

It's hard to burn large numbers of calories with exercise alone, unless
you have a lot of time on your hands.

I did that for about six months (aerobic exercise for
30-60 minutes, at least six days per week) and lost less than 5kg.

Try 18 hours of walking per day, and you'll see the effect almost
immediately. I've been there, and done that. The numbers work out
perfectly.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

On Wed, 08 Oct 2003 16:59:38 -0700, Michael Snyder wrote:
Mxsmanic wrote:
Michael Snyder writes:

Well yes -- everybody does it. We do it behind closed doors, but
no one but you seems to be under the delusion that we don't do it.


Malabsorption syndromes are rather dramatically different. When you
have a lot of fats or sugars going through the gut without being
absorbed, it produces some pretty explosive symptoms. It is not subtle,
and it is not normal.

By definition, since YOU introduced the term "mal" into it.
Nevertheless, *normal* excreta does contain available fuel --
which is why flies eat it. Thus the recourse to thermodynamics
is not justified -- food energy in does not equal metabolic
energy expended. As I said, the system is more complex than that.

nutritional food calories do not include those potential chemical energy
calories.

Fissile Uranium has no food caloric value.

On Thu, 9 Oct 2003 23:43:55 +1000, RLW wrote:
I believe I already explained why in a previous post. Different
macronutrients have different amounts of energy intrinsically within their
chemical bonds. Both fat and carbohydrate can be metabolised completely to
water and carbon dioxide, so I can see why you'd think calories from them
would be identical. However, when carbohydrate is converted and stored in
adipose tissue, more energy is lost than when fat is stored. Conversion of
carbohydrate and protein to fat stores requires them to undergo an
inefficient chemical conversion and therefore energy is lost. When fat is
deposited into adipose tissue, there is no real chemical conversion
necessary and hence there is little energy lost. That's why the body heats
up during exercise: because the body's chemical reactions are inefficient.
*Theoretically*, you could eat a slightly higher calorie diet if it had a
greater percentage of its calories from protein and carbs, than one which
had a greater percentage of its calories from fat, and maintain the same
body fat composition. Like I said, though, the body is complex and I'll
take good experimental evidence over theory any day.

That's all true, but that extra inefficiency in converting food
will go to heat.

Your body attempts to regulate your temperature very carefully,
because that is a key parameter in many biologically important
reactions. And it does so quite accurately, within 1 degree of
300 or so.

Thus, if you gain extra heat in the process of converting
macronutrient "P" versus "C", you will likely not actually expend more
energy, because your body will downregulate the consumption of other
stores that it would ordinarily use to heat you up to the desired
equilibrium temperature.

Basic metabolic rate appears from empirical observation to be
very strongly conserved.

If certain macronutrient combinations were shown by strict
experimentation to actually increase basic metabolic rate as opposed
to others, then that would be an important result. But I do not
think it is the case to a significant degree in any normal regime
of dietary intake.

I tried to find exact amounts of energy lost for these reactions in my
undergrad biochem textbook, but they didn't give any. It's been a while
since I studied biochemistry to be honest. I can't be arsed to go down to
the library for a usenet debate when I have a lot better things to do with
my time.

If you can cite some solid evidence to show that 100 calories of fat and 100
calories of protein or carbohydrate are stored as the same amount of adipose
tissue in the human body, I'd be interested in seeing it and would recant my
position immediately.

No that is not the assertion. But if you maintain a long-term energy
deficit, then fat stores are eventually the only major place that the
body will be able to find enough stored energy to account for its
consumption.

In the meantime, I shall say that I think the most effective way to lose
weight is to cut caloric intake. From my own experiences, exercise by
itself while maintaining a contant caloric intake did practically nothing to
change my weight. I did that for about six months (aerobic exercise for
30-60 minutes, at least six days per week) and lost less than 5kg.

Losing 5kg is not completely insignificant in 6 months. But it is
also true that the scientific consensus is that cutting caloric intake
significantly is what is necessary for weight loss---however exercise
is very important for maintaining that loss, and has additional health
benefits.

The weights people also say that it will change your body composition.

Yeah, I know what they are. I've got a BSc in Chemistry.

Then why do you base your position on biology?

I was talking about biochemical processes within the body, which are based
on chemistry.

However, I also studied biology, microbiology, biochemistry, and a few other
subjects before finally settling on organic chemistry as my major.

You may have the last word if you wish. I'm not going to waste any more
time on this thread.

Discussing scientific facts are usually profitable.

Rowena.

On Thu, 09 Oct 2003 21:01:46 +0200, Mxsmanic wrote:

The usual calorie equivalents for different macronutrients take this
overhead into account. That's why fat is often assigned 7 kcal per
gram, even though it actually contains 9 kcal per gram. The 2 kcal
difference is the overhead of converting fat to and from fat.

see my other posting---given the body's desire to maintain a constant
temperature, it is not clear that the 2kcal deficit really is one.

The conversion produces heat.

In other words, since the body has to burn certain number of calories
to maintain temperature already, the "losses" in conversion aren't
necessarily net losses at all.

"Michael Snyder" wrote in message ...
Ralph DuBose wrote in message ...
Michael Snyder wrote in message ...
Ralph DuBose wrote:
"Michael Snyder" wrote in message ...

Mxsmanic wrote in message ...

Mr. F. Le Mur writes:


True, but I think the idea is if you don't eat anough fat, then
you still have cravings (for fat) and eat more calories-worth
of stuff with less fat.



Oxygen is needed for aerobic metabolic processes but it is not
"energy" per se. My point is not nit picking because you do not seem
to understand anything about this subject.

It is not nit-picking -- it is a red herring. Show me where I claimed
that oxygen is energy per se. I said you cannot derive metabolic
energy from food without oxygen. The rest of your statement is
content-free and reveals information about you, not me.

Evidence is accumulating that you do not want top hear certain
things. There have been several referrences to the fact that no one
stays fat in boot camps or prison camps, that they all lose fat in a
hurry. This is a non-trivial fact in the context of the original title
of this thread. If you expect to be taken at all seriously, this is a
point with which you must deal. Waving your hand and expecting it to
go away does not work real well when the medium of dialogue is all
permanent and written.

Ralph DuBose wrote:
"Michael Snyder" wrote in message ...

Ralph DuBose wrote in message ...

Michael Snyder wrote in message ...

Ralph DuBose wrote:

"Michael Snyder" wrote in message ...


Mxsmanic wrote in message ...


Mr. F. Le Mur writes:



True, but I think the idea is if you don't eat anough fat, then
you still have cravings (for fat) and eat more calories-worth
of stuff with less fat.


Oxygen is needed for aerobic metabolic processes but it is not
"energy" per se. My point is not nit picking because you do not seem
to understand anything about this subject.

It is not nit-picking -- it is a red herring. Show me where I claimed
that oxygen is energy per se. I said you cannot derive metabolic
energy from food without oxygen. The rest of your statement is
content-free and reveals information about you, not me.


Evidence is accumulating that you do not want top hear certain
things. There have been several referrences to the fact that no one
stays fat in boot camps or prison camps, that they all lose fat in a
hurry. This is a non-trivial fact in the context of the original title
of this thread. If you expect to be taken at all seriously, this is a
point with which you must deal. Waving your hand and expecting it to
go away does not work real well when the medium of dialogue is all
permanent and written.

Nor has anyone here addressed the equally real fact that people
often go on reduced-calorie diets and do not lose weight. Waving
your hand and expecting it to go away does not work real well...

Michael Snyder writes:

Nor has anyone here addressed the equally real fact that people
often go on reduced-calorie diets and do not lose weight.

That never happens.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

On Thu, 09 Oct 2003 16:04:31 -0700, Michael Snyder wrote:

Nor has anyone here addressed the equally real fact that people
often go on reduced-calorie diets and do not lose weight.

True, they "go on reduced-calorie diets", but do not
reduced actually consumed calories. Underestimating consumed
calories is a fact, and has a serious effects on research
studies which correlate obesity to disease, by significantly
lowering the apparent health risks relative to true health risks.

J Nutr. 2003 Mar;133 Suppl 3:895S-920S. Related Articles, Links

Markers of the validity of reported energy intake.

Livingstone MB, Black AE.

School of Biomedical Sciences, University of Ulster at Coleraine,
Northern Ireland, UK.

Energy intake (EI) is the foundation of the diet, because all
other nutrients must be provided within the quantity of food needed to
fulfill the energy requirement. Thus if total EI is underestimated, it
is probable that the intakes of other nutrients are also
underestimated. Under conditions of weight stability, EI equals energy
expenditure (EE). Because at the group level weight may be regarded as
stable in the timescale of a dietary assessment, the validity of
reported EI can be evaluated by comparing it with either measured EE
or an estimate of the energy requirement of the population. This paper
provides the first comprehensive review of studies in which EI was
reported and EE was measured using the doubly labeled water
technique. These conclusively demonstrate widespread bias to the
underestimation of EI. Because energy requirements of populations or
individuals can be conveniently expressed as multiples of the basal
metabolic rate (BMR), EE:BMR, reported EI may also be expressed as
EI:BMR for comparison. Values of EI:BMR falling below the 95%
confidence limit of agreement between these two measures signify the
presence of underreporting. A formula for calculating the lower 95%
confidence limit was proposed by Goldberg et al. (the Goldberg
cutoff). It has been used by numerous authors to identify individual
underreporters in different dietary databases to explore the variables
associated with underreporting. These studies are also comprehensively
reviewed. They explore the characteristics of underreporters and the
biases in estimating nutrient intake and in describing meal patterns
associated with underreporting. This review also examines some of the
problems for the interpretation of data introduced by underreporting
and particularly by variable underreporting across subjects. Future
directions for research are identified.

J Am Diet Assoc. 2001 Jan;101(1):70-80. Related Articles, Links

Biased over- or under-reporting is characteristic of individuals
whether over time or by different assessment methods.

Black AE, Cole TJ.

Medical Research Council Dunn Nutrition Centre, Cambridge, England.

Seven studies with repeated measurements of energy intake and/or
nitrogen intake were examined to determine whether misreporting is
characteristic of some persons or occurs randomly. Four of the studies
were validated by doubly labeled water measurements of energy
expenditure. Reporting validity was expressed as the ratio of energy
intake to energy expenditure. Ratios were consistently below the
expected value of 1.0 for some subjects and consistently above 1.0 for
others, indicating characteristic reporting validity within
subjects. Two year-long studies provided 4 to 12 measurements and a
total number of days sufficient to measure individual habitual
intake. Subjects mean energy intake to basal metabolic rate (BMR)
ratios were 1.35 in 45% and 47% and 1.35 at every measurement in
25% of subjects. This indicated persistent underreporting over time,
because 1.35 x BMR is the minimum energy expenditure compatible with a
normally active lifestyle. Three of the studies used more than 1
assessment method (validated by doubly labeled water and/or urinary
nitrogen excretion). There was a tendency for persons determined to be
underreporters by 1 method to be also underreporters when tested by
other methods. We conclude that biased over- or underreporting is
characteristic of some persons. Thus, repeat measurements do not
necessarily provide valid measures of individual intake, extreme
intakes may reflect under- and overreporting rather than true low or
high intakes, and subjects most prone to reporting bias may be
repeatedly misclassified in quantiles of the distribution. This
presents a challenge to dietitians nutritionists, and statisticians
both for the design of surveys and the handling of flawed data.




Am J Epidemiol. 2003 Jul 1;158(1):14-21; discussion 22-6. Related
Articles, Links

Structure of dietary measurement error: results of the OPEN
biomarker study.

Kipnis V, Subar AF, Midthune D, Freedman LS, Ballard-Barbash R,
Troiano RP, Bingham S, Schoeller DA, Schatzkin A, Carroll RJ.

Biometry Research Group, Division of Cancer Prevention, National
Cancer Institute, Bethesda, MD 20892-7354, USA.

Multiple-day food records or 24-hour dietary recalls (24HRs) are
commonly used as "reference" instruments to calibrate food frequency
questionnaires (FFQs) and to adjust findings from nutritional
epidemiologic studies for measurement error. Correct adjustment
requires that the errors in the adopted reference instrument be
independent of those in the FFQ and of true intake. The authors report
data from the Observing Protein and Energy Nutrition (OPEN) Study,
conducted from September 1999 to March 2000, in which valid reference
biomarkers for energy (doubly labeled water) and protein (urinary
nitrogen), together with a FFQ and 24HR, were observed in 484 healthy
volunteers from Montgomery County, Maryland. Accounting for the
reference biomarkers, the data suggest that the FFQ leads to severe
attenuation in estimated disease relative risks for absolute protein
or energy intake (a true relative risk of 2 would appear as 1.1 or
smaller). For protein adjusted for energy intake by using either
nutrient density or nutrient residuals, the attenuation is less severe
(a relative risk of 2 would appear as approximately 1.3), lending
weight to the use of energy adjustment. Using the 24HR as a reference
instrument can seriously underestimate true attenuation (up to 60% for
energy-adjusted protein). Results suggest that the interpretation of
findings from FFQ-based epidemiologic studies of diet-disease
associations needs to be reevaluated.

Am J Epidemiol. 2003 Jul 1;158(1):1-13. Related Articles, Links

Using intake biomarkers to evaluate the extent of dietary
misreporting in a large sample of adults: the OPEN study.

Subar AF, Kipnis V, Troiano RP, Midthune D, Schoeller DA, Bingham
S, Sharbaugh CO, Trabulsi J, Runswick S, Ballard-Barbash R, Sunshine
J, Schatzkin A.

Applied Research Program, Division of Cancer Control and
Population Sciences, National Cancer Institute, Bethesda, MD,
USA.

This paper describes the Observing Protein and Energy Nutrition
(OPEN) Study, conducted from September 1999 to March 2000. The purpose
of the study was to assess dietary measurement error using two
self-reported dietary instruments-the food frequency questionnaire
(FFQ) and the 24-hour dietary recall (24HR)-and unbiased biomarkers of
energy and protein intakes: doubly labeled water and urinary
nitrogen. Participants were 484 men and women aged 40-69 years from
Montgomery County, Maryland. Nine percent of men and 7% of women were
defined as underreporters of both energy and protein intake on 24HRs;
for FFQs, the comparable values were 35% for men and 23% for women. On
average, men underreported energy intake compared with total energy
expenditure by 12-14% on 24HRs and 31-36% on FFQs and underreported
protein intake compared with a protein biomarker by 11-12% on 24HRs
and 30-34% on FFQs. Women underreported energy intake on 24HRs by
16-20% and on FFQs by 34-38% and underreported protein intake by
11-15% on 24HRs and 27-32% on FFQs. There was little underreporting of
the percentage of energy from protein for men or women. These findings
have important implications for nutritional epidemiology and dietary
surveillance.


-----------------------------------------









J Am Diet Assoc. 2003 Sep;103(9):1146-51. Related Articles, Links

Personality characteristics as predictors of underreporting of
energy intake on 24-hour dietary recall interviews.

Novotny JA, Rumpler WV, Riddick H, Hebert JR, Rhodes D, Judd JT,
Baer DJ, McDowell M, Briefel R.

US Department of Agriculture, Agricultural Research Service,
Beltsville Human Nutrition Research Center, Diet and Human Performance
Laboratory, Beltsville, MD 20705, USA.

OBJECTIVE: To identify characteristics associated with
misreporting of energy intake during 24-hour dietary recalls (24
HR). DESIGN: Ninety-eight subjects were administered two 24
HRs. Energy expenditure was determined by doubly labeled water (44
subjects) or intake balance (54 subjects). Data on subjects' physical,
lifestyle, and psychosocial characteristics were also
collected. Subjects/setting At the Beltsville Human Nutrition Research
Center 52 women and 46 men were administered 24HR and completed
lifestyle and personality questionnaires and a memory test. Physical
characteristics such as weight, percent body fat, and total energy
expenditure were measured. Statistical analysis The influences of
subject parameters on energy misreporting were assessed by linear
regression and Pearson product-moment correlation analysis for
continuous variables and by ANOVA for discrete variables. Stepwise
regression was used to identify key factors in
underreporting. RESULTS: Factors particularly important in predicting
underreporting of energy intake include factors indicating
dissatisfaction with body image; for example, a 398 kcal/day
underreport in subjects attempting weight loss during the past year
with a nearly 500 kcal/day underreport in women. Overall, women
underreported by 393 kcal/day relative to men and women evinced a
social desirability bias amounting to a 26 kcal underreport for each
point on the social desirability scale. Gender differences also were
evident in the effect of percent body fat (with men underreporting
about 16 kcal/day/percent body fat) and in departure from
self-reported ideal body weight (with women underreporting about 21
kcal/day/kg). APPLICATIONS/CONCLUSIONS: Body image and fatness are key
factors on which health professionals should focus when seeking
predictors of underreporting of dietary intake. Dietary interviews
must be conducted to minimize bias related to subjects' tendencies to
win approval and avoid censure by the interviewer. In addition,
dissatisfaction with body image may lead to underestimation of food
intake, therefore reducing likelihood of success in weight loss. Thus,
health care professionals involved in weight loss counseling may
achieve better success if treatment includes generating a more
positive body image.

Int J Eat Disord. 2001 May;29(4):470-6. Related Articles, Links

Total energy expenditure as measured by doubly-labeled water in
outpatients with bulimia nervosa.

Kotler LA, Devlin MJ, Matthews DE, Walsh BT.

Department of Child and Adolescent Psychiatry, Columbia
University/New York State Psychiatric Institute, New York, New York,
USA.

OBJECTIVE: This study measured total energy expenditure (TEE) in
symptomatic outpatient women with bulimia nervosa and normal
controls. The study aimed to test the conceptual model of bulimia
nervosa as an illness characterized by a physiological state of
starvation, despite normal weight. METHOD: Total fat and fat-free mass
were measured using hydrodensitometry and total energy expenditure was
assessed via the doubly-labeled water method, in nine normal weight
outpatient females with DSM-III-R bulimia nervosa and ten healthy
female controls. RESULTS: Patients and controls were similar in age,
body mass index, weight, lean body mass, and levels of exercise and
general activity. Patients had an average baseline binge frequency of
14.7 episodes per week and purge frequency of 16.8 times per week, and
had been ill for an average of 11.9 years. Group mean TEE did not
differ between patients and controls (patients 2380 +/- 482 kcal/day,
controls 2368 +/- 515 kcal day). Observed TEE in the bulimic subjects
did not differ significantly from TEE predicted on the basis of data
from the controls. DISCUSSION: This finding of normal TEE in
symptomatic outpatients with bulimia nervosa is consistent with a
previous study that found no difference in TEE in a sample of
symptomatic inpatients with bulimia nervosa. These data suggest that
the energy conserving metabolic adaptations characteristic of
semi-starvation do not occur in patients with bulimia
nervosa. Copyright 2001 by John Wiley & Sons, Inc.

"RLW" wrote in message ...
"Mxsmanic" :
RLW writes:

Actually it is, insofar as it is burned. Some of the kinetic energy is
organized to perform work; the rest is disorganized and is lost as heat.

And other forms of energy.

The human body is the same way.

Right.

I was saying that not all calories get converted to the same
amount of fat.

But they do. That's why there is only one kind of dietary calorie.

I feel like I'm banging my head on a brick wall.

You've yet to demonstrate to me that that isn't true.

The burden of prove falls upon you. If you believe that all calories
are not the same, you must explain your belief, because by default they
are identical (which is why they all use the same
I believe I already explained why in a previous post. Different
macronutrients have different amounts of energy intrinsically within their
chemical bonds. Both fat and carbohydrate can be metabolised completely to
water and carbon dioxide, so I can see why you'd think calories from them
would be identical. However, when carbohydrate is converted and stored in
adipose tissue, more energy is lost than when fat is stored. Conversion of
carbohydrate and protein to fat stores requires them to undergo an
inefficient chemical conversion and therefore energy is lost. When fat is
deposited into adipose tissue, there is no real chemical conversion
necessary and hence there is little energy lost. That's why the body heats
up during exercise: because the body's chemical reactions are inefficient.
*Theoretically*, you could eat a slightly higher calorie diet if it had a
greater percentage of its calories from protein and carbs, than one which
had a greater percentage of its calories from fat, and maintain the same
body fat composition. Like I said, though, the body is complex and I'll
take good experimental evidence over theory any day.

The body is indeed complex, but it is also very efficient with
regard to energy matters. For example, better than 99% of available
nutrients are extracted from food. Also, the chemical reactions you
refer to are all driven along by enzymes which are highly evolved and
very efficient, so the energy loss involved in these conversions is
smaller than one would guess.
Every healthy human has a extremely efficient metabolism, it does
not make sense that fat people could have even more efficiency.
Because that is what is being claimed when people say that they stay
fat despite less food and more exercise.
They are claiming that they have better efficiency than ordinary, fit,
healthy people -- that their bodies can do more work of all types with
the same amount of fuel than other folks.
There is no experimental evidence for the existence of this sort of
thing (and lots to the contrary) and solid theoretical grounds for
doubting it could happen. There is not much room for improvement over
normal.
Far too much money and thought has been devoted to the problem.
Anyone serious about weight loss need only push exercise and diet
restriction hard enough and they will get there. Just don't start with
preconceived ideas about how hard one must push these things, it may
be harder than the diet pimps are telling you.




I tried to find exact amounts of energy lost for these reactions in my
undergrad biochem textbook, but they didn't give any. It's been a while
since I studied biochemistry to be honest. I can't be arsed to go down to
the library for a usenet debate when I have a lot better things to do with
my time.

If you can cite some solid evidence to show that 100 calories of fat and 100
calories of protein or carbohydrate are stored as the same amount of adipose
tissue in the human body, I'd be interested in seeing it and would recant my
position immediately.

In the meantime, I shall say that I think the most effective way to lose
weight is to cut caloric intake. From my own experiences, exercise by
itself while maintaining a contant caloric intake did practically nothing to
change my weight. I did that for about six months (aerobic exercise for
30-60 minutes, at least six days per week) and lost less than 5kg.

Yeah, I know what they are. I've got a BSc in Chemistry.

Then why do you base your position on biology?

I was talking about biochemical processes within the body, which are based
on chemistry.

However, I also studied biology, microbiology, biochemistry, and a few other
subjects before finally settling on organic chemistry as my major.

You may have the last word if you wish. I'm not going to waste any more
time on this thread.

Rowena.