Adiposty 101 updated 
Author Message
 Adiposty 101 updated

Keywords: adiposty obesity genetics diet exercise research
Lines: 958
Organization: Omen Technology, Portland

                                  - 1 -

       1.  FOREWORD

       This is a summary of information on the causes and treatment
       of overweight I've gleaned over the years from forays to the
       Med School library and from other sources.  I hope this
       summary provides useful information on obesity.  Some of you
       may be able to fill in gaps mentioned here.

       2.  BACKGROUND

       Adipose Cell: There are two types of adipose (fat) cell,
       White Adipose Tissue (WAT) and Brown Adipose Tissue (BAT).

       Set Point Theory: A biological servo system controls energy
       expenditures, fat cell receptors, appetite, and other
       physical characteristics to return the body to a constant
       weight (set point) after periods of starvation or

       Rats and pigs are commonly used in adiposty research because
       their fat mechanisms closely resemble those of humans.

       Body Mass Index (BMI) is a measure of the percentage of fat
       to total body mass.  BMI is used as a height and bone-
       density independent measure of adiposty.

       Morbid obesity: Obesity severe enough to directly limit the
       victim's health or quality of life.

       Refactory: Adjective indicating the condition reasserts
       itself, precluding long term relief.


       One source of obesity is overeating from emotional stress.

       Experiments with controlled overfeeding of lean subjects
       demonstrate an increase in body metabolism that restores
       normal weight when overfeeding ceases.

       In a 1986 Dutch study, some men who experienced many life
       events in a short period showed a gain in body mass.  A year
       later this weight gain had disappeared in almost all
       subgroups, EXCEPT those that tried to lose weight by

       My area of interest is chronic adiposty, in which the
       subject is heavier than average most of his life.

                               Adiposty 101

                                  - 2 -


       4.1  Brown Adipose Tissue (BAT)

       Brown Adipose Tissue (BAT) generates heat (thermogenisis) by
       burning calories without physical motion.

       4.2  White Adipose Tissue (WAT)

       Obesity results from an excess of white adipose tissue

       WAT cells are not simple storage tanks.  These are active,
       living cells.  They convert steroid hormones to estrogen.
       White Fat cells compete with lean tissue for nutrients,
       interfering with normal muscle development.

       The fact that reduction of fat cell numbers (see below)
       causes permanent fat loss while weight loss techniques that
       do not reduce the number of fat cells are temporary suggests
       that the white fat cells themselves are the "set    point"

       4.3  Preadipocytes > Fat      Cells

       White fat cells begin life as PREADIPOCTYES.

       Adipose tissue from {*filter*} humans contains a pool of tiny
       precursor cells (preadipocytes) which can be converted to
       adipocytes (fat cells) in the presence of glucocorticoids
       and insulin.  (Journal of Clinical Endocrinology and
       Metabolism, 1987).

       The adiposty of individual pigs can be predicted by
       measuring the ability of the suckling's {*filter*} to
       differentiate preadipocytes into full size fat cells in a
       test tube.  The preobese sucklings had low levels of fetal
       growth hormone and high levels of triiodothyronine.

       4.3.1  Size and Number of Fat Cells  Is obesity caused by an
       excess number of fat cells or by gross enlargement of a
       normal number of fat cells?  The answer to this question has
       heavy implications for the possible success of various
       weight loss strategies.

       A study published in the Proceedings of the 5th
       International Congress on Obesity showed that obese subjects
       who had lost weight in a combined diet/exercise program had
       fat cells 25 per cent smaller than those of trained athletes
       who had half the fat.  In other words, the dieters had twice
       as many fat cells as the athletes.  (Dieting does not reduce

                               Adiposty 101

                                  - 3 -

       the number of fat cells.)

       4.4  Fat Cell Receptors

       Fat cells gain and lose weight by passing lipids through
       receptors.  One type of receptor removes lipids from the
       {*filter*} stream and another type allows the body to access the
       energy stored in the fat cells with a resulting loss of

       Geographic distribution of fat, including "love handles"
       that do not respond to extreme dieting, is believed to
       result from local variations in these receptors. No diet or
       exercise has been shown to have geographic specificity in
       fat reduction.

       The numbers and efficiencies of the two receptor types
       change with repeated dieting, promoting weight gain.

       4.5  Muscle Fibre Type

       The April 19 1990 Lancet reports that skeletal muscle fibre
       type is directly correlated with BMI.  Lean subjects have
       more "slow fibers" well endowed with mitochondria that use
       fatty acids as energy source.  Corpulent subjects have more
       "fast fibers" that cannot burn fat for energy. (See
       EXERCISE, below.) (1D-5) (1D-7)


       The conclusion of current research is that individual
       differences in Body Mass Index (BMI) are mostly the result
       of genetic factors.

       Two studies published this year in the New England Journal
       of Medicine illustrate the point.

       In "The body-mass index of twins    who have been reared
       apart", the rearing environment was shown to have no effect
       on BMI.  In other words, if you're fat, it wasn't because
       your mother fed you too many cookies and it wasn't because
       your father didn't make you exercise.

       In "The response    to long-term overfeeding in identical
       twins", 12 pairs    of identical male twins were overfed and
       kept sedentary under close supervision.  There was a 3 to 1
       ratio in weight gain between the easiest gainer and the
       slowest gainer.  Those who gained the most fat gained less
       muscle than those who gained the least fat.  Ten of the 12
       pairs of identical twins gained almost identical amounts of

                               Adiposty 101

                                  - 4 -


       This study is interesting because of its sample selection.
       None of the subjects had any history of obesity whatsoever,
       not even in their families. One can but imagine what that 3
       to 1 spread would have been if subjects with a history of
       weight problems had been included.

       The appearance of these papers in the New England Journal of
       Medicine prompted several submissions questioning the
       papers' findings.  These letters and the authors' replies
       are printed in the Oct 11 1990 edition.

       The Sep 1990 Science News reported a very wide difference in
       the amounts and types of tissues added in response to
       overfeeding.  The thin people actually added more weight
       than fat people did, but the thin people added weight mainly
       as lean tissue instead of fat.  Data from "lean hungry"
       types that gained little weight were excluded.

       5.1  The Role of Maternal Environment

       What one's mother does or eats during or immediately before
       pregnancy affects one's BMI.  The May 1990 METABOLISM
       reported that changes in the rat sow's diet during early
       pregnancy had a permament effect on pups' lipid metabolism.

       An Aug 5 1990 BBC broadcast reported that the size of a baby
       relative to the size of the placenta had a greater
       correlelation on {*filter*} {*filter*} pressure than the combined
       effects of weight or {*filter*} consumption.

       As reported in the Health InfoCom Network News Volume  3,
       Number 36 December  5, 1990, Dr.  Bernard Silverman of
       Children's Memorial  Hospital  in  Chicago  says a study  of
       124 children whose mothers were either diabetic before
       pregnancy or became diabetic during it showed:  Children at
       normal weight at age 1.  Many were obese by 6 to 8.  At 8,
       the median weight was 71 pounds for boys;  normal median -
       56 pounds. Median for girls was 68 pounds; normal medium 55
       pounds.  Some researchers say the pre{*filter*}s' obesity may be
       due to excess insulin  in the  amniotic  fluid  surrounding
       them  during  gestation.

                               Adiposty 101

                                  - 5 -

       5.2  The Role of Baby's Diet

       A Case Western Reserve University rat study (4P-17) compared
       rat pups fed a milk-substitute formula (56% of calories from
       carbohydrates) with mother-fed controls (only 8% of calories
       from carbohydrates).  "The results show that alterations    in
       the source of calories rather than the total caloric intake
       during the suckling period can have specific long-lasting
       effects on lipid metabolism in {*filter*}hood, leading to the
       development of obesity."

       This result supports the assertion of a Reader's Digest
       article that {*filter*} feeding can "Fat Proof" one's baby.
       Left unanswered is the question: at what age should the
       suckling's low carbohydrate diet evolve to the high
       carbohydrate low fat diet favored by health authorities?


       6.1  Personality Problems

       The correlation between psychological problems and obesity
       is well known.  Many couches have been filled with patients
       wishing to lose weight.  As the nature and

read more »

Tue, 01 Jun 1993 11:13:00 GMT
 Adiposty 101 updated
I'm posting an updated version of my "Adiposty 101" article.

Quite a bit of interesting research has been reported since
the first posting, and is included in the posting.

There have been a few net.flames too.  One or two promised to
produce research reports to back up their views, but
none have provided any.

Chuck Forsberg WA7KGX          ...!tektronix!reed!omen!caf
Author of YMODEM, ZMODEM, Professional-YAM, ZCOMM, and DSZ
  Omen Technology Inc    "The High Reliability Software"
17505-V NW Sauvie IS RD   Portland OR 97231   503-621-3406
TeleGodzilla:621-3746 FAX:621-3735 CIS:70007,2304 Genie:CAF

Tue, 01 Jun 1993 11:19:27 GMT
 Adiposty 101 updated

I wonder to what extent biological polymorphism is involved in obesity.

The survival of the species as a whole benefits if different individuals
have different physical characteristics. Some of us are designed to
survive famines, and others are designed to function better when">food
is abundant. By trying to fit us all into the same mold, modern medicine
may be making a big mistake.

My own experience, and that of my wife, losing weight is...

  (1) Exercise works better than calorie-counting would suggest.

  (2) Caloric restriction works worse than calorie-counting would

  (3) An abundance of nourishing foods tends to lead to weight loss,
  or at least control. Intermittent lack of">food or of nutrients
  leads to weight gain.

  (4) The slower the better.

  (5) On starting a medically supervised diet, my wife suddenly got
  over a long-lasting sore throat/sinus/nasal problem. She was tested
  for">food allergies and turned out to be severely allergic to corn.
  Eliminating corn from her diet has kept her weight in control;
  I wonder if the allergy was involved in her overeating in the first
  place. (If you call it overeating...)

  (6) Some fat people (e.g., me) eat a lot less than some thin people!

  (I'm not all that fat -- maybe 20 pounds overweight at the most --
  but enough to be concerned about weight control.)

Tue, 01 Jun 1993 14:47:54 GMT
 [ 3 post ] 

 Relevant Pages 

1. Adiposty 101

2. Updated Adiposity 101 (long)

3. New Adiposity 101

4. Adiposity 101

5. Obesity research dollars (was Adiposity 101)

6. Andiposity 101

7. Fever (> 101 F) and pregnancy

8. Need Adiposity 101 article

9. Correction to Adiposity 101

10. formula 101

11. Adiposity 101 4/4

12. DC/ Asthma/Bronchial Physiology 101 again!

Powered by phpBB® Forum Software