A Critical Review of Human Psychology and Behavior Research to Examine the Biological and Methodological Plausibility of Obesity Research Findings Candace.

A Critical Review of Human Psychology A Critical Review of Human Psychology and Behavior Research to Examine the and Behavior Research to Examine the

Biological and Methodological Biological and Methodological Plausibility of Obesity Research Plausibility of Obesity Research

FindingsFindings

Candace D. Rutt, Ph.D.

Centers for Disease Control and Prevention

The Importance of the IndividualThe Importance of the Individual

How does individual psychology and How does individual psychology and behavior interact with the environment to behavior interact with the environment to affect caloric intake and caloric affect caloric intake and caloric expenditure?expenditure?

Increasing ObesityIncreasing Obesity

Results about caloric intake over time Results about caloric intake over time have been mixedhave been mixedOver the last several decades daily energy Over the last several decades daily energy expenditure has decreasedexpenditure has decreased– Leisure-time activity Leisure-time activity – Occupational physical activity Occupational physical activity – Activities of daily livingActivities of daily living

Increase in attractive sedentary activitiesIncrease in attractive sedentary activities(James, 1995; McArdle et al., 1997)(James, 1995; McArdle et al., 1997)

Caloric IntakeCaloric Intake

Hunger is not determined by biological Hunger is not determined by biological mechanisms alonemechanisms alone

PreferencesPreferences– InnateInnate– ExperienceExperience– CulturalCultural

(Abbot et al., 1998; Berthoud & Seeley, 2000; Birch & Marlin, (Abbot et al., 1998; Berthoud & Seeley, 2000; Birch & Marlin, 1982; Birch et al., 1980; Birch et al., 1984; Birch et al., 1987; 1982; Birch et al., 1980; Birch et al., 1984; Birch et al., 1987; Grundy, 1998; Lipsitt &Behl, 1990; Weingarten, 1983)Grundy, 1998; Lipsitt &Behl, 1990; Weingarten, 1983)

Caloric IntakeCaloric Intake

Portion sizesPortion sizesIncreased varietyIncreased varietyPresence of othersPresence of othersAvailability of foodAvailability of foodMore time in automobilesMore time in automobiles– Preference for convenience foodsPreference for convenience foods– Easy access while driving Easy access while driving

(Berry et al., 1985; Bureau of the Census, 1976; 2000; Center for Science (Berry et al., 1985; Bureau of the Census, 1976; 2000; Center for Science in Public Interest, 2003; Edelman et al., 1986; Polivy et al., 1979 Porikos in Public Interest, 2003; Edelman et al., 1986; Polivy et al., 1979 Porikos et al., 1982; Rolls et al., 1992; Rolls & Hetherington, 1989)et al., 1982; Rolls et al., 1992; Rolls & Hetherington, 1989)

Physical ActivityPhysical Activity

30 minutes of moderate to vigorous 30 minutes of moderate to vigorous physical activity on most days of the weekphysical activity on most days of the week

Community GuideCommunity Guide– Enhanced access with informational outreachEnhanced access with informational outreach– Street-scale urban designStreet-scale urban design– Community-scale urban designCommunity-scale urban design

Physical Activity and the Physical Activity and the EnvironmentEnvironment

Characteristics of the environment may Characteristics of the environment may have various impacts on different types of have various impacts on different types of physical activities physical activities

Variations of environmental impact on Variations of environmental impact on physical activity and obesity seen in physical activity and obesity seen in different populationsdifferent populations

Walking for TransportationWalking for Transportation

Density (+)Density (+)

Land-use mix (+)Land-use mix (+)

Connectivity (+)Connectivity (+)

Sidewalks (+)Sidewalks (+)

High walkable neighborhood (+)High walkable neighborhood (+)

Car ownership (-)Car ownership (-)

Access to beach (-)Access to beach (-)(Frank & Engelke, 2001; 2002; Giles-Corti., 2002; Moudon et al., 1997; (Frank & Engelke, 2001; 2002; Giles-Corti., 2002; Moudon et al., 1997;

Ross & Dunning, 1997; Saelens et al., 2003)Ross & Dunning, 1997; Saelens et al., 2003)

Walking for LeisureWalking for Leisure

Density (na) Density (na) Connectivity (na) Connectivity (na) Sidewalks (+ na)Sidewalks (+ na)Land-use (+ and -)Land-use (+ and -)Convenient Facilities (+ and na)Convenient Facilities (+ and na)Sprawl (-)Sprawl (-)High walkable neighborhood (na)High walkable neighborhood (na)Traffic (- and +)Traffic (- and +)Hills (+)Hills (+)Safety (+ and -)Safety (+ and -)Aesthetics (+)Aesthetics (+)Costal location (+)Costal location (+)

(Ball et al., 2001; Brownson et al., 2001; de Bourdeaudhuij et al., 2003; (Ball et al., 2001; Brownson et al., 2001; de Bourdeaudhuij et al., 2003; Ewing et al., 2003; Hovel et al., 1989; 1992; Humpel et al., 2004;Rutt & Ewing et al., 2003; Hovel et al., 1989; 1992; Humpel et al., 2004;Rutt & Coleman, in press; Saelens et al., 2003)Coleman, in press; Saelens et al., 2003)

Moderate & Vigorous Physical Moderate & Vigorous Physical ActivityActivity

Density (na)Density (na)Land-use (na)Land-use (na)Connectivity (na) Connectivity (na) Sidewalks (+ and na) Sidewalks (+ and na) Heavy traffic (+)Heavy traffic (+)Access to parks (+)Access to parks (+)Number of facilities (na)Number of facilities (na)Availability of pay facilities (+) Availability of pay facilities (+) Distance to facilities (+)Distance to facilities (+)Slope (na)Slope (na)Hills (+)Hills (+)

(Brownson et al., 2001 ; King et al., 2000; Rutt & Coleman, in press; (Brownson et al., 2001 ; King et al., 2000; Rutt & Coleman, in press; Saelens et al., 2003; Sallis et al., 1990)Saelens et al., 2003; Sallis et al., 1990)

ObesityObesity

Density (+ and na)Density (+ and na)

Connectivity (na)Connectivity (na)

Land-use mix (- and +) Land-use mix (- and +)

Sprawl (+) Sprawl (+)

Living in high walkable neighborhoods (-)Living in high walkable neighborhoods (-)

Lack of sidewalks (+) Lack of sidewalks (+)

Time spent in car (+)Time spent in car (+)

Owning a car (+)Owning a car (+)(Bell & Popkin, 2003; Ewing et al., 2003; Frank et al., 2004; Giles-Corti (Bell & Popkin, 2003; Ewing et al., 2003; Frank et al., 2004; Giles-Corti

et al., 2003; Saelens et al., 2003; Reddy et al., 1997; Rutt & et al., 2003; Saelens et al., 2003; Reddy et al., 1997; Rutt & Coleman, in press)Coleman, in press)

Reasons for InconsistenciesReasons for Inconsistencies

No standardized way to measure many No standardized way to measure many environmental variables environmental variables

Poor agreement between subjective and Poor agreement between subjective and objective measures of the environmentobjective measures of the environment

High correlations between urban form High correlations between urban form variables variables

Individual level characteristics Individual level characteristics (Kirtland et al., 2003; Sallis et al., 1990; Troped et al., 2001)(Kirtland et al., 2003; Sallis et al., 1990; Troped et al., 2001)

Individual Level DifferencesIndividual Level Differences

Variations in environmental correlates Variations in environmental correlates seen acrossseen across– GenderGender– EthnicityEthnicity– Income Income (de Bourdeadhuij, 2003; Flynn & Fitzgibbon, 1998; Flegal et al., (de Bourdeadhuij, 2003; Flynn & Fitzgibbon, 1998; Flegal et al.,

1998; Humpel et al,. 2004; 2004; Voorhees & Young, 2003; )1998; Humpel et al,. 2004; 2004; Voorhees & Young, 2003; )

Individual Level DifferencesIndividual Level Differences

46% of adults in the U.S. believe that their 46% of adults in the U.S. believe that their neighborhood is unsafe. This rate was neighborhood is unsafe. This rate was doubledouble in minority households in minority households

Residents of poor neighborhoods walk Residents of poor neighborhoods walk more despite the fact that they report more more despite the fact that they report more fear of being victimized fear of being victimized (Princeton Survey Research Associates, 1994; Ross, 2000)(Princeton Survey Research Associates, 1994; Ross, 2000)

Individual Level DifferencesIndividual Level Differences

For those with low incomes, the most For those with low incomes, the most important environmental variable important environmental variable associated with walking was enjoyable associated with walking was enjoyable sceneryscenery

For those with higher incomes sidewalks For those with higher incomes sidewalks were the most important variable were the most important variable (Brownson et al., 2001)(Brownson et al., 2001)

Reasons for InconsistenciesReasons for Inconsistencies

Most studies include some basic Most studies include some basic demographic variablesdemographic variables

Usually do not measure psychological or Usually do not measure psychological or social variables that could affect behaviorsocial variables that could affect behavior

Self-selection into neighborhoodsSelf-selection into neighborhoods– Individual level characteristics associated with Individual level characteristics associated with

certain types of neighborhoodscertain types of neighborhoods

Reasons for InconsistenciesReasons for Inconsistencies

Households choose residential locations partly Households choose residential locations partly based on desired travel behaviorbased on desired travel behavior

Several researchers have found clusters of Several researchers have found clusters of lifestyle and demographic variables that were lifestyle and demographic variables that were linked to transportation choices linked to transportation choices

Attitudinal and demographic variables have Attitudinal and demographic variables have been foundbeen found to be more strongly associated with to be more strongly associated with travel than built environment characteristicstravel than built environment characteristics(Boarnet & Sarmiento, 1998; Boarnet & Greenwald, 2000; Cervero (Boarnet & Sarmiento, 1998; Boarnet & Greenwald, 2000; Cervero

& Duncan, 2003; Giles-Corti & Donovan, 2002; Kitamura et & Duncan, 2003; Giles-Corti & Donovan, 2002; Kitamura et al.,1997; Hanson, 1982; Rutt & Coleman, in press; Salomon & al.,1997; Hanson, 1982; Rutt & Coleman, in press; Salomon & Ben Akiva, 1983; Zimmerman, 1982)Ben Akiva, 1983; Zimmerman, 1982)

Mode choiceMode choice

Only one study which has examined travel Only one study which has examined travel behavior before and after a movebehavior before and after a move– Over half of the families moved to similar Over half of the families moved to similar

neighborhoodsneighborhoods– Decreases in walking and biking trips were seen Decreases in walking and biking trips were seen

in those that relocated from a low auto-dependent in those that relocated from a low auto-dependent neighborhood to a medium auto-dependent neighborhood to a medium auto-dependent neighborhoodneighborhood

(Krizek, 2000)(Krizek, 2000)

Mode choiceMode choice

Travel time is the most important predictor Travel time is the most important predictor of mode choiceof mode choice

Out-of-vehicle travel time (walking, biking) Out-of-vehicle travel time (walking, biking) is considered more costly than in-vehicle is considered more costly than in-vehicle travel time travel time

However other components of the trips However other components of the trips (aesthetics, safety, etc.) affect the price or (aesthetics, safety, etc.) affect the price or utility of the trip utility of the trip (Handy et al., 2002)(Handy et al., 2002)

Variance ExplainedVariance Explained

Of the six classes of determinants Of the six classes of determinants (demographic, psychological, behavioral, (demographic, psychological, behavioral, social, environment), individual level social, environment), individual level variables had the strongest and most variables had the strongest and most consistent associations with physical consistent associations with physical activityactivityStudies usually explain only 30% of the Studies usually explain only 30% of the variance in physical activity or travel variance in physical activity or travel behavior behavior (Crane et al., 1999; Baranowski, 1998; Handy et al., 1996)(Crane et al., 1999; Baranowski, 1998; Handy et al., 1996)

Environment and PAEnvironment and PA

An environment that encourages physical An environment that encourages physical activity is necessary but insufficient to activity is necessary but insufficient to increase physical activity increase physical activity

We may need better measures of the We may need better measures of the environmentenvironment(Trost et al., 1996)(Trost et al., 1996)

Paradigm ShiftParadigm Shift

Cannot examine how the environment influences Cannot examine how the environment influences physical activity, eating behavior, or obesity physical activity, eating behavior, or obesity without examining the individualwithout examining the individual

Researchers need to start thinking about Researchers need to start thinking about interactions between variables as well as their interactions between variables as well as their independent effectsindependent effects– Ecological ModelsEcological Models– MediatorsMediators– ModeratorsModerators

(Barron & Kenny, 1986; McLeroy, Bibeau, Steckler, & Glantz, 1988; Sallis & (Barron & Kenny, 1986; McLeroy, Bibeau, Steckler, & Glantz, 1988; Sallis & Owen, 1996; Stokols, 1996)Owen, 1996; Stokols, 1996)

ConclusionsConclusions

Individual level variables should not be Individual level variables should not be simply viewed as “covariates” to be simply viewed as “covariates” to be controlled for rather they should be examined controlled for rather they should be examined as important predictors of travel behavior and as important predictors of travel behavior and physical activityphysical activity

If individual level variables are not included in If individual level variables are not included in the emerging literature, incorrect conclusions the emerging literature, incorrect conclusions may be drawn about the relationship may be drawn about the relationship between the environment and obesitybetween the environment and obesity