Técnicas e instrumentos de recolección de datos

Increasingly,  long  held  beliefs  predicated  on  anti-­‐obesity  research  that  excess  weight  is   associated  with  dire  health  consequences,  are  being  challenged   (e.g.,  Jerant  &  Franks,   2012).  Health,  or  more  particularly  avoiding  illness,  is  a  reason  why  people  decide  to   lose   weight.   It   is   therefore   important   to   understand   what   the  health   implications   of   excess  weight  are  and  whether  health  is  a  reasonable  ground  on  which  to  encourage  a   person  to  lose  weight.  

A   systematic   review   of   the   associations   between   weight   and   disease   has   attributed   up   to   18   co-­‐morbidities   to   overweight   and   obesity   (Guh   et   al.,   2009).   For   women,   some   of   these   include   breast,   endometrial,   ovarian,   colorectal,   and   other   cancers;   cardiovascular   and   metabolic   disease;   kidney   and   gall   bladder   disease;   asthma;   sleep   apnea;   and   osteoarthritis   (Guh   et   al.,   2009;   Kim   &   Popkin,   2006;   Olshansky   et   al.,   2005;   Pi-­‐Sunyer,   2002a).   A   discussion   of   all   these   co-­‐morbidities   is   beyond  the  scope  of  my  thesis.  However,  because  the  literature  on  weight  often  focuses   on   the   incidence   of   type   II   diabetes   and   heart   disease   as   reasons   why   people   should   lose  weight,  a  brief  discussion  of  these  two  co-­‐morbidities  is  warranted  here.  

Type   II   diabetes,   which   impacts   on   quality   of   life,   is   more   common   in   obesely   overweight  people.  Research  suggests  that  a  woman  with  a  BMI  over  30  has  a  28-­‐fold   increased   risk   of   developing   the   disease   compared   to   a   woman   with   a   BMI   of   21   (Kopelman,   2000).   However,   there   is   also   evidence   that   being   overweight   or   having   class  I  obesity  per  se  are  not  necessarily  associated  with  increased  morbidity  (Jerant  &   Franks,  2012).  Rather,  the  suggestion  is  that  it  is  gaining  weight  that  increases  the  risk   of   developing   diabetes   relative   to   maintaining   a   stable   weight.   This   finding   has   implications  for  people  who  lose  weight  and  subsequently  regain  the  weight  lost.  

There  is  interplay  with  obesity,  diabetes,  and  heart  disease.  Research  finds  that   people   with   obesity   are   prone   to   develop   type   II   diabetes   but   the   reverse   is   also   the   case   since   people   with   type   II   diabetes   are   likely   to   become   obesely   overweight   and   both   are   at   risk   of   developing   cardiovascular   disease   (Rana,   Nieuwdorp,   Jukema,   &   Kastelein,   2007).   The   suggestion   is   that   obesity,   diabetes,   cardiovascular   disease   and   cancers   are   all   symptoms   of   something   else,   like   the   consumption   of   refined   carbohydrates,   starches,   and   sugars   (Taubes,   2008).   Type   II   diabetes   can   be   significantly   improved   through   a   healthy   diet,   limiting   refined   carbohydrates,   and  

engaging   in   adequate   regular   exercise   (McAuley   &   Blair,   2011).   Since   this   is   entirely   independent  of  weightloss,  it  suggests  that  more  emphasis  should  be  placed  on  lifestyle   rather   than   focusing   on   weight   or   BMI   (Campos   et   al.,   2006;   Gaesser,   1999).   A   connection  to  diet  and  exercise  is  not  unique  to  diabetes.  

High  blood  pressure  (hypertension)  and  heart  disease  are  presumed  to  co-­‐vary   with   weight.   There   seems   to   be   a   relationship   between   increasing   BMI   and   heart   disease  such  that  a  woman  with  BMI  over  29  has  a  3.6-­‐fold  increased  risk  of  developing   the   disease   compared   to   a   woman   with   a   BMI   below   21   (Kopelman,   2000).   In   saying   this  though,  upper  body  fat  is  an  important  mediator  here.  A  pear-­‐shaped  woman,  one   who  carries  much  of  her  body  fat  around  her  hips  and  thighs,  with  a  correspondingly   low   waist-­‐to-­‐hip   ratio   has   a   one-­‐half   heart   disease   risk   compared   to   a   woman   with   small   hips   relative   to   her   waist   (Kopelman,   2000).   In   this   regard,   waist-­‐to-­‐hip   ratios   and   waist   circumference   measures   are   better   predictors   of   both   heart   diseases   and   type  II  diabetes  than  BMI  (Guh  et  al.,  2009;  Van  Pelt  et  al.,  2001).  

Significantly,   many   obesely   overweight   people   have   entirely   normal   blood   pressures  and  for  those  who  do  not,  hypertension  can  be  markedly  improved  through   diet   and   exercise   independent   of   weightloss   (Gaesser,   2002).   A   connection   has   been   found  with  blood  pressure  and  weight  fluctuation  or  yo-­‐yo  dieting  however  (Guagnano   et  al.,  2000;  O'Reilly  &  Sixsmith,  2012).  Obese  people  are  more  likely  to  diet  than  slim   people  (Bish  et  al.,  2005).  With  dieting  often  resulting  in  yo-­‐yoing  or  weight  cycling,  it  is   argued   that   the   association   between   obesity   and   high   blood   pressure   may   simply   be   due  to  obese  individuals  yo-­‐yoing  more  (Gaesser,  2002).  

The   important   point   to   make   here   is   that   the   relationship   between   weight   and   health  is  convoluted  and  complex.  The  health  and  illness  concerns  around  overweight   and  obesity  are  being  questioned  (e.g.,  Bacon  &  Aphramor,  2011;  Gaesser,  2003).  For   instance,  some  researchers  (Campos  et  al.,  2006;  Flegal,  Graubard,  Williamson,  &  Gail,   2005)   point   to   evidence   of   rising   life   expectancy   and   decreasing   mortality   rates   for   heart   disease   seemingly   going   hand-­‐in-­‐hand   with   an   increased   incidence   of   obesity.   Furthermore  studies  have  reported  evidence  of  obesity  paradoxes,  whereby  increased   body  weight  offers  a  survival  advantage  (e.g.,  McAuley  &  Blair,  2011;  S.  Morse,  Gulati,  &   Reisin,  2010).  

There   is   also   increasing   evidence   that   the   co-­‐morbidities   purported   to   be   associated   with   weight   can   be   mitigated   by   diet   and   physical   exercise   (e.g.,   Gaesser,   2002;  Warburton,  Nicol,  &  Bredin,  2006).  Healthful  food  choices  and  physical  exercise   impact   on   health   and   are   argued   to   be   better   predictors   of   health   than   BMI   (e.g.,   Campos,  2004;  Gaesser,  2002).  But,  while  there  is  a  relationship  for  instance  between   fruit   and   vegetable   intake   and   disease   (Bazzano   et   al.,   2002),   and   obesity   (Ledoux,  

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Hingle,   &   Baranowski,   2010),   this   relationship   may   be   confounded   by   socioeconomic   status.  Healthful  food  choices  such  as  fruit  and  vegetables  can  be  expensive  such  that   nutritionally   poor   and   energy-­‐dense   foods   are   sometimes   chosen   simply   because   of   price   (Konttinen,   Sarlio-­‐Lähteenkorva,   Silventoinen,   Männistö,   &   Haukkala,   2012).   Clearly,   the   relationship   between   BMI   and   morbidity,   and   health   and   losing   weight   is   not  straightforward  or  simple.