I came across this at a Health Canada website.

from What Approaches Have Been Used to Foster Healthy Lifestyles and are they
Effective?
http://www.hc-sc.gc.ca/hppb/phdd/docs/healthy/chap3.html   Health Canada Website

""The difficulty encountered when trying to change lifestyle (heart disease
prevention) in individuals from a
  low socio-economic neighbourhood is illustrated in a Montreal study
(O'Loughlin et al., 1999). This 4-year,
  community-based cardiovascular disease prevention program was aimed at adults
aged 18 to 65 years
  living in St-Henri, a low-income, inner-city neighborhood. Over 40
interventions were implemented (i.e.,
  smoking cessation workshops, contests, heart health cooking classes and recipe
 contests, nutrition
  education workshops, direct mail and ad campaigns...). The authors address the
 substantial challenges
  of working in a community in which social and economic problems were a greater
 priority than heart
  health. Although they carefully adapted each intervention to local needs, the
results were dismal. [emphasis added]
  Awareness of the program reached 37.4%, but participation was low (2%-3%).
There were no significant
  decreases in smoking or high-fat diet, and physical inactivity increased. In
the longitudinal cohort sample,
  there was a small, statistically significant increase favoring St-Henri in
frequency of cholesterol checkups.
  The authors attribute their findings to a general lack of participation in the
 program, and the lack of
  commitment by community groups to sustain the activities. For example, the
responsibility to continue a
  morning walking group could not be devolved to community groups. The authors
state:

   ..."unless or until basic living needs are ensured, persons living in
low-income
   circumstances will be unlikely or unable to view CVD [cardio-vascular
disease] prevention
   as a priority. Second, while local community groups and agencies can be
mobilized to
   participate in and take leadership for selected interventions, it is
difficult for these groups to
   maintain a sustained commitment, since these activities are often simply
added onto
   existing agendas with few additional resources. They have difficulty
sustaining long term
   commitment...because national and local health priorities change over time
(O



'Loughlin et
   al., 1999, pp.1824-1825). ""