Sarah-Jeanne Salvy PhD
Research Associate Professor
Room: CHP 133
Phone: (323) 442-2069
Sarah-Jeanne Salvy, a child clinical and pediatric psychologist, focuses on the physical and social determinants of obesity and on translating evidence-based practices into scalable and sustainable models of childhood obesity prevention in at-risk populations. She has been Principal Investigator of two NIH grants totaling over 1.8 million dollars. Salvy is a fellow of the USC Leonard D. Schaeffer Center for Health Policy & Economics, a fellow of the USC Dornsife Center for Economic and Social Research and an adjunct behavioral and social scientist at the RAND Corporation (Santa Monica, Calif.).
Postdoctoral Fellowship in Social Psychology
University of Toronto
Doctor of Philosophy (PhD) in Clinical Psychology
University of Montreal
Bachelor of Science (BS) in Psychology
University of Quebec at Montreal
Barkley, J. E., Salvy, S. J., Sanders, G. J., Dey, S., Von Carlowitz, K. P., & Williamson, M. L. (2014). Peer influence and physical activity behavior in young children: An experimental study. Journal of Physical Activity & Health, 11, 404-409. doi:10.1123/jpah.2011-0376. Link to full text
BACKGROUND: There is evidence that the presence of a friend increases physical activity behavior in school-aged children (≥ 8 years old) and in young adolescents. Little is known about the developmental trajectory of the effects of peer influences on children's physical activity. Therefore, we sought to test the effect of the presence versus absence of a friend on physical activity in young children (≤ 6 years old).
METHODS: Physical activity was assessed, via accelerometery, in 3- to 6-year-old children, during 2 social conditions: alone and in the presence of a friend. During each condition, children were taken to a gymnasium and had free access to physical and sedentary activities for 30 minutes. In one condition children were tested alone (solo play), whereas in the other they were tested in the presence of a friend who had access to the same activities.
RESULTS: Children exhibited 54% greater (P < .02) average accelerometer counts during the friend condition (mean = 2629, SD = 1080 or 5.7 METs) than during the solo play condition (mean = 1707, SD = 1009 or 4.5 METs).
CONCLUSIONS: The presence of a friend contributes to increased physical activity behavior in young children.
Salvy, S. J., Bowker, J. C., Nitecki, L. A., Kluczynski, M. A., Germeroth, L. J., & Roemmich, J. N. (2012). Effects of ostracism and social connection-related activities on adolescents' motivation to eat and energy intake. Journal of Pediatric Psychology, 37, 23-32. doi:10.1093/jpepsy/jsr066. Link to full text
OBJECTIVE: Assess the effect of ostracism and social connection-related activities on adolescents' motivation to eat and their energy intake.
METHODS: Participants (n = 103; M age = 13.6 years) were either ostracized or included when playing a computer game, Cyberball. Next, they wrote about their friend (social-connection), watched television (distraction), or completed Sudoku puzzles (cognitive-load), and then completed a task to earn points toward snack food and/or socializing. Afterwards, participants were given access to food and social activities.
RESULTS: Ostracized adolescents were more motivated to earn food than adolescents who were in the included/control condition. Follow-up contrasts indicated that ostracized adolescents who wrote about friends worked more for food points and consumed more food than other adolescents.
CONCLUSION: Results suggest that social connection-related activities following ostracism may further deplete self-regulatory resources, thereby resulting in increased unhealthy food patterns. Study limitations as well as clinical implications of these findings are discussed.
Hermans, R. C., Salvy, S. J., Larsen, J. K., & Engels, R. C. (2012). Examining the effects of remote-video confederates on young women's food intake. Eating Behaviors, 13, 246-251. doi:10.1016/j.eatbeh.2012.03.008. Link to full text
One's decisions about eating are at times, largely based on the observations of other people's eating behavior. Previous studies have shown that modeling of eating is a robust effect. The current research examined the impact of a video remote confederate on young women's food intake. Experiment 1 examined the effect of an eating or non-eating video confederate. Participants (N=77 female undergraduate students, M age=20.29) were exposed to a same-sex video confederate (i.e., a 25 year old woman) who was modeling eating (i.e., 4 winegums; pastille-type sweets) or not eating (i.e. no food visible). Results indicated that participants exposed to the eating confederate did not eat more than participants exposed to the non-eating confederate. Experiment 2 was conducted to address some of the limitations of Experiment 1. In this experiment, participants (N=51, M age=20.43) were exposed to one of three intake conditions: No-eating (i.e. food visible but not consumed), Small portion-size condition (i.e., 8 M&Ms) or Large portion-size condition (i.e., 20 M&Ms). The same video confederate as in Experiment 1 modeled these three conditions. Results indicated that participants did not adjust their intake to that of a video model. The current findings provide preliminary evidence for the assumption that modeling only exists if people have clear indications about how much others have consumed in the same context (as was the case in previous modeling studies). Future research is needed to further examine this proposition.
Salvy, S. J., Bowker, J. C., Germeroth, L., & Barkley, J. (2012). Influence of peers and friends on overweight/obese youths' physical activity. Exercise and Sport Sciences Reviews, 40, 127-132. doi:10.1097/JES.0b013e31825af07b. Link to full text
This review offers a theoretical framework to account for the effects of peers on youths' physical activity. Our research indicates the following: 1) that the youth are more physically active in the presence of friends and peers than in the presence of family members or when alone, 2) peers and friends increase overweight/obese youths' motivation to be physically active, 3) peers' weight status does not moderate the effect of peers on youths' physical activity, and 4) experiencing negative peer interaction, such as ostracism, decreases physical activity in youth. We propose that the consideration of the peer social context as a contributor to physical (in)activity and maintenance of overweight status may further our understanding of physical and behavioral health trajectories and improve prevention and intervention efforts.
Salvy, S. J., Kluczynski, M. A., Nitecki, L. A., & O'Connor, B. C. (2012). Peer influence on youth's snack purchases: A laboratory analog of convenience store shopping. Eating Behaviors, 13, 233-239. doi:10.1016/j.eatbeh.2012.03.005. Link to full text
OBJECTIVE: This paper reports the results of two experiments using a laboratory analog to examine the influence of taxes and subsidies on youth's snack food purchases when alone (Experiment 1) and when in the presence of a same-gender peer (Experiment 2).
METHOD: Adolescents (12-14-years-old) completed a purchasing task, during which prices of snack foods were manipulated, either alone in Experiment 1 (N=37) or in the presence of an unfamiliar peer in Experiment 2 (N=52).
RESULTS: In both experiments, purchases of unhealthy snacks decreased and purchases of healthy snacks increased when the price of unhealthy snacks were taxed (increased). In Experiment 1 (alone), participants did not purchase more healthy snacks when the price of these snacks were subsidized (decreased). However, in Experiment 2 (when participants were in the presence of a peer), participants purchased more healthy snacks when these snacks were subsidized.
CONCLUSION: Taxes and subsidies affect adolescents' snack purchasing, as does the presence of peers. The results of this study highlight factors that influence healthy and unhealthy snack purchasing behavior in young adolescents.
Barkley, J. E., Salvy, S. J., & Roemmich, J. N. (2012). The effect of simulated ostracism on physical activity behavior in children. Pediatrics, 129, e659-e666. doi:10.1542/peds.2011-0496. Link to full text
OBJECTIVES: To assess the effects of simulated ostracism on children's physical activity behavior, time allocated to sedentary behavior, and liking of physical activity.
METHODS: Nineteen children (11 boys, 8 girls; age 11.7 ± 1.3 years) completed 2 experimental sessions. During each session, children played a virtual ball-toss computer game (Cyberball). In one session, children played Cyberball and experienced ostracism; in the other session, they were exposed to the inclusion/control condition. The order of conditions was randomized. After playing Cyberball, children were taken to a gymnasium where they had free-choice access to physical and sedentary activities for 30 minutes. Children could participate in the activities, in any pattern they chose, for the entire period. Physical activity during the free-choice period was assessed via accelerometery and sedentary time via observation. Finally, children reported their liking for the activity session via a visual analog scale.
RESULTS: Children accumulated 22% fewer (P < .01) accelerometer counts and 41% more (P < .04) minutes of sedentary activity in the ostracized condition (8.9(e+4) ± 4.5(e+4) counts, 11.1 ± 9.3 minutes) relative to the included condition (10.8(e+4) ± 4.7(e+4) counts, 7.9 ± 7.9 minutes). Liking (8.8 ± 1.5 cm included, 8.1 ± 1.9 cm ostracized) of the activity sessions was not significantly different (P > .10) between conditions.
CONCLUSIONS: Simulated ostracism elicits decreased subsequent physical activity participation in children. Ostracism may contribute to children's lack of physical activity.
Salvy, S. J., de la Haye, K., Bowker, J. C., & Hermans, R. C. (2012). Influence of peers and friends on children's and adolescents' eating and activity behaviors. Physiology & Behavior, 106, 369-378. doi:10.1016/j.physbeh.2012.03.022. Link to full text
Obesity during childhood and adolescence is a growing problem in the United States, Canada, and around the world that leads to significant physical, psychological, and social consequences. Peer experiences have been theoretically and empirically related to the "Big Two" contributors to the obesity epidemic, unhealthy eating and physical inactivity. In this article, we synthesize the empirical literature on the influence of peers and friends on youth's eating and physical activity. Limitations and issues in the theoretical and empirical literatures are also discussed, along with future research directions. In conclusion, we argue that the involvement of children's and adolescents' peer networks in prevention and intervention efforts may be critical for promoting and maintaining positive behavioral health trajectories. However, further theoretical and empirical work is needed to better understand the specific mechanisms underlying the effects of peers on youth's eating and physical activity.
Salvy, S. J., Bowker, J. C., Nitecki, L. A., Kluczynski, M. A., Germeroth, L. J., & Roemmich, J. N. (2011). Impact of simulated ostracism on overweight and normal-weight youths' motivation to eat and food intake. Appetite, 56, 39-45. doi:10.1016/j.appet.2010.11.140. Link to full text
There is growing evidence that the experience of being ostracized can impair individuals' abilities to self-regulate, which in turn, leads to negative health behaviors, such as increased unhealthy eating. Research has focused on adults, but deficits in eating regulation in response to ostracism may be particularly detrimental for overweight or obese youth. This study examines the effects of a brief episode of ostracism on the motivation to eat and food intake of overweight and normal-weight young adolescents (M age=13.6 years). A computerized ball-tossing game (Cyberball) was used to induce ostracism or inclusion. Following the inclusion/ostracism manipulation, all participants completed an operant computer task to earn points exchangeable for portions of food or for time socializing with an unfamiliar peer. Participants' responses for food and their subsequent energy intake were recorded. As hypothesized, ostracized overweight participants responded more for food and had a greater energy intake than overweight participants in the inclusion/control condition; whereas this was not the case for normal-weight participants. These results are important as studies indicate that overweight and obese youth may be at risk of social isolation and peer difficulties. Social adversity, if left unchanged, may increase the difficulty of promoting long-term changes in overweight youths' health behaviors.
Rittenhouse, M., Salvy, S. J., & Barkley, J. E. (2011). The effect of peer influence on the amount of physical activity performed in 8- to 12-year-old boys. Pediatric Exercise Science, 23, 49-60. Link to full text
The purpose of this study was to determine the amount of physical and sedentary activity normal-weight and at-risk-for/overweight boys perform when alone, with a peer of similar weight and with a peer of different weight. Participants included boys, ages 8-12 years, classified as either normal-weight (<85th BMI percentile; N = 12) or at-risk-for/overweight (<85th BMI percentile; N = 12). At-risk-for/ overweight boys allocated a greater amount of time to sedentary activities and accumulated fewer accelerometer counts than normal-weight boys in the alone condition. Once paired with a peer of either similar or different weight there were no differences between groups. These results indicate the presence of an unknown peer has a positive effect on at-risk-for/overweight children's physical activity behavior.
Salvy, S. J., Elmo, A., Nitecki, L. A., Kluczynski, M. A., & Roemmich, J. N. (2011). Influence of parents and friends on children's and adolescents' food intake and food selection. American Journal of Clinical Nutrition, 93, 87-92. doi:10.3945/ajcn.110.002097. Link to full text
BACKGROUND: The influence of parents versus friends on youths' eating behavior has not been directly compared, and little is known about the developmental effects of social influences on their eating behavior.
OBJECTIVE: The objective was to compare the effects of mothers and friends on children's and adolescents' energy intake from sandwiches and from healthy and unhealthy snacks and dessert foods.
DESIGN: Twenty-three children (ages 5-7 y) and 27 adolescents (ages 13-15 y) ate a meal with their mother on one occasion and with a same-sex friend on another occasion.
RESULTS: Male and female children consumed less energy from unhealthy snacks when in the presence of their mothers than when in the company of their friends. Conversely, female adolescents consumed less energy from unhealthy snacks and more energy from healthy snacks when they were with their friends than when with their mothers.
CONCLUSIONS: Food selection is differentially influenced by the source of social influence and the age and sex of the child. Parents may act as an inhibitory influence on unhealthy eating for younger children. Adolescent girls may try to convey a good impression of healthy eating when eating with same-sex friends, but the eating habits of teenage boys are not as influenced by the social context. This trial is registered at clinicaltrials.gov as NCT00875576.
Epstein, L. H., Salvy, S. J., Carr, K. A., Dearing, K. K., & Bickel, W. K. (2010). Food reinforcement, delay discounting and obesity. Physiology & Behavior, 100, 438-445. doi:10.1016/j.physbeh.2010.04.029. Link to full text
Choice is a central construct in behavioral economics, with choice research divided into choice of concurrent alternative reinforcers, which is conceptualized as relative reinforcing value, or choice of small immediate versus larger delayed rewards, usually of the same commodity, which is conceptualized as delay of gratification and delay discounting. Relative reinforcing value, delay of gratification and delay discounting paradigms can be used to study obesity, which involves strong motivation to obtain and consume food reinforcers. Strong food reinforcement and difficulties in delay of gratification are risk factors for child weight gain, and both are related to individual differences in overweight/obesity. Delay discounting interacts with food reinforcement to predict energy intake. We provide a selective review of research on each of these areas, and argue that the division of choice into reinforcing value versus delay discounting is based on an arbitrary definition based on the temporality of choices. We present a model that integrates reinforcing value and delay discounting approaches. Implications of this theoretical approach to better understand excess energy intake and obesity are discussed. The paper represents an invited review by a symposium, award winner or keynote speaker at the Society for the Study of Ingestive Behavior [SSIB] Annual Meeting in Portland, July 2009.
Bowker, J. C., Spencer, S. V., & Salvy, S. J. (2010). Examining how overweight adolescents process social information: The significance of friendship quality. Journal of Applied Developmental Psychology, 31, 231-237. http://dx.doi.org/10.1016/j.appdev.2010.01.001. Link to full text
The current study examines the social information processing and coping styles (SIP) of overweight and average weight adolescents, and whether the associations between friendship quality and SIP differ for these two groups (N = 156, M age = 12.79). On the basis of height and weight assessments, overweight (n = 70) and average weight (n = 86) adolescents were identified. Participants reported on positive and conflictual qualities of their friendships, and their attributions, emotional reactions, and coping strategies in response to hypothetical negative peer events. Results revealed that for overweight adolescents, positive friendship quality was negatively associated with emotion-focused coping, and friendship conflict was positively associated with internal blame attributions, but the associations between these variables were not significant for average weight adolescents. Findings suggest that positive friendships may represent protective factors in the lives of overweight adolescents whereas highly conflictual friendships may increase risk.
Roemmich, J. N., Lambiase, M., Salvy, S. J., & Horvath, P. J. (2009). Protective effect of interval exercise on psychophysiological stress reactivity in children. Psychophysiology, 46, 852-861. doi:10.1111/j.1469-8986.2009.00808.x. Link to full text
Two studies determined whether interval exercise reduces children's stress reactivity. For Experiment 1 children completed interval exercise (n=14) or watched TV (n=14) for 25 min. After 20 min rest children completed a speech task. Speech-induced diastolic blood pressure (DBP) reactivity was dampened in the exercise group (p<.05). For Experiment 2 children (n=22) completed interval exercise-speech and TV-speech conditions on separate days. Physical activity was assessed by accelerometry and aerobic fitness estimated by submaximal exercise. DBP, systolic BP, and heart rate (HR) reactivity to the speech stressor were dampened (p<.05) after exercise compared to TV watching. Fitness was positively associated with HR reactivity. Interval exercise that mimics usual patterns of physically active play dampens cardiovascular reactivity to interpersonal stress.
Salvy, S. J., Roemmich, J. N., Bowker, J. C., Romero, N. D., Stadler, P. J., & Epstein, L. H. (2009). Effect of peers and friends on youth physical activity and motivation to be physically active. Journal of Pediatric Psychology, 34, 217-225. doi:10.1093/jpepsy/jsn071. Link to full text
OBJECTIVE: To test whether the presence of a peer or a friend increases the motivation to be physically active in overweight and non-overweight youth in a laboratory setting.
METHODS: Youth motivation to be physically active as a function of the social context was measured using a computerized relative reinforcing value task to earn points exchangeable for physical and/or sedentary activities.
RESULTS: The presence of a friend (p<.001) increased youth's; motivation to be physically active. The presence of a peer increased overweight youth's; motivation to be physically active, whereas this was not the case for lean youth (p=.47). Participants biked a greater distance in the presence of a friend than when alone (p<.001). Overweight youth biked a greater distance in the presence of a peer than when alone, while this was not the case for lean youth (p=.23).
CONCLUSIONS: Friendships may increase youth's motivation to engage in physical activity and promote greater physical activity in non-overweight and overweight youth.
Salvy, S. J., Nitecki, L. A., & Epstein, L. H. (2009). Do social activities substitute for food in youth?. Annals of Behavioral Medicine, 38, 205-212. doi:10.1007/s12160-009-9145-0. Link to full text
BACKGROUND: Behavioral economics offers a framework to understand choice among alternatives. There is no research on the interrelationship between food and social activity in overweight and non-overweight children.
PURPOSE: The purpose of this study is to test the substitutability of food and social interactions using behavioral economic methods in overweight and non-overweight youth.
METHODS: Fifty-four (24 males and 30 females) overweight and non-overweight youth aged 9 to 11 years old were tested using a behavioral choice paradigm which involved participants responding to earn points exchangeable for food and/or social activity.
RESULTS: Youth substituted food for social activities when the cost of social time with an unfamiliar peer increased (p < 0.05) and substituted food for social activities with an unfamiliar peer when the cost of food increased (p < 0.05). However, when interacting with a friend was the alternative, participants did not substitute food for social interactions.
CONCLUSIONS: Social interactions can serve as a substitute for food in both lean and overweight youth.
Havermans, R. C., Salvy, S. J., & Jansen, A. (2009). Single-trial exercise-induced taste and odor aversion learning in humans. Appetite, 53, 442-445. doi:10.1016/j.appet.2009.08.006. Link to full text
In the present study, it was investigated whether humans acquire an aversion for a flavor paired with a single bout of exercise, and if so, to what degree this effect requires the experience of gastrointestinal distress. To this end, a total of 58 participants either consumed or merely tasted a specifically flavored solution directly prior to a 30 min running exercise. In both cases this led to a negative shift in subjective liking of the flavor (taste and odor) in comparison to the evaluation of another flavor not explicitly paired with exercise, indicative of a conditioned flavor aversion. The degree of subjectively experienced exercise-related gastrointestinal distress did not predict this negative hedonic shift for the flavor paired with the running exercise, implying that such distress may not be a prerequisite for exercise-induced flavor aversion learning in humans.
Romero, N. D., Epstein, L. H., & Salvy, S. J. (2009). Peer modeling influences girls' snack intake. Journal of the American Dietetic Association, 109, 133-136. doi:10.1016/j.jada.2008.10.005. Link to full text
Previous studies indicate that the presence of peers influences children's food consumption. It is assumed that one factor producing this effect in children is child modeling of food intake. The present study assesses the effect of a video model on the food intake of overweight (n=22) and nonoverweight (n=22) preadolescent girls. A 2 (weight status)x2 (small vs large serving size) factorial design was used to test the hypothesis that youth model others' food intake. Serving sizes were manipulated by showing a video model selecting and consuming either a small or a large serving of cookies. Results indicate a main effect of serving size condition, F(1,40)=5.1, P<0.05 (d=0.65; 95% confidence interval: 0.35 to 0.65), and a main effect of weight status, F(1,40)=4.9, P<0.05 (d=0.63; 95% confidence interval: 0.35 to 0.65). Participants exposed to the large serving-size condition consumed more cookies than participants exposed to the small serving-size condition and overweight participants consumed considerably more cookies than nonoverweight participants. The interaction of weight status by serving-size condition did not reach statistical significance (P=0.2). These results suggest that peer-modeling influences overweight and nonoverweight preadolescent girls' snack consumption.
Salvy, S. J., Howard, M., Read, M., & Mele, E. (2009). The presence of friends increases food intake in youth. American Journal of Clinical Nutrition, 90, 282-287. doi:10.3945/ajcn.2009.27658. Link to full text
BACKGROUND: Friendship may be uniquely relevant and influential to youths' eating behavior.
OBJECTIVE: This study examined how overweight and nonoverweight youths adjust their level of eating as a function of their familiarity with their eating partner.
DESIGN: Twenty-three overweight and 42 nonoverweight youths had the opportunity to play and eat with a friend (n = 26) or with an unfamiliar peer (n = 39). The dependent variables of interest were the amount of nutrient-dense and energy-dense foods children consumed and their total energy intake.
RESULTS: Participants eating with a friend ate substantially more than did participants eating with an unfamiliar peer. Furthermore, overweight youth, but not nonoverweight youth, who ate with an overweight partner (friend or unfamiliar peer) consumed more food than did overweight participants who ate with a nonoverweight eating partner. Matching of intake was greater between friends than between unfamiliar peers.
CONCLUSIONS: These results extend previous research by suggesting that the effect of the partners' weight statuses may add to the facilitative effect of familiarity and result in greater energy intake in overweight youth and their friends. Behavioral similarity among overweight youth may increase the difficulty of promoting long-term changes because the youths' social network is likely to reinforce overeating. This trial was registered at clinicaltrials.gov as NCT00874055.
Wrotniak, B. H., Salvy, S. J., Lazarus, L., & Epstein, L. H. (2009). Motor proficiency relationships among siblings. Perceptual and Motor Skills, 108, 112-120. doi:10.2466/pms.108.1.112-120. Link to full text
The purpose of this study was to examine motor proficiency relations of siblings. 23 sibling pairs ages 5 to 13 years were studied. Motor proficiency was assessed by the Bruininks-Oseretsky Test of Motor Proficiency-Short Form of 14 items, adjusting for Body Mass Index percentile, age, and sex. The association among siblings' overall motor proficiency was not statistically significant. When each of the 14 items in the test was examined separately, significant associations were found. Items positively associated among siblings included walking on a balance beam, tapping feet and making circles, and sorting shape cards. Copying a picture of overlapping pencils and making dots in circles were inversely related. The results indicate that siblings may share certain motor-skill components of balance, bilateral coordination, and upper limb speed or dexterity, but do not necessarily have the same global motor competence. Additional research is needed to explain relations in motor skills among siblings.
Mageau, G. A., Vallerand, R. J., Charest, J., Salvy, S. J., Lacaille, N., Bouffard, T., & Koestner, R. (2009). On the development of harmonious and obsessive passion: The role of autonomy support, activity specialization, and identification with the activity. Journal of Personality, 77, 601-646. doi:10.1111/j.1467-6494.2009.00559.x. Link to full text
Recent research (Vallerand et al., 2003) has supported the existence of two types of passion for activities: a harmonious and an obsessive passion. The purpose of this investigation was to study the processes likely to lead to the development of passion. Three studies using correlational and short-term longitudinal designs with varied populations ranging from beginners to experts reveal that identification with the activity, activity specialization, parents' activity valuation, and autonomy support predict the development of passion. Furthermore, results show that children and teenagers whose environment supports their autonomy are more likely to develop a harmonious passion than an obsessive one. Conversely, children and teenagers who highly value activity specialization, who rely heavily on their activity for self-definition, and whose parents highly value the activity are more likely to develop an obsessive passion.
Salvy, S. J., Vartanian, L. R., Coelho, J. S., Jarrin, D., & Pliner, P. P. (2008). The role of familiarity on modeling of eating and food consumption in children. Appetite, 50, 514-518. http://dx.doi.org/10.1016/j.appet.2007.10.009. Link to full text
This study investigates the effects of peer and sibling influence on the cookie intake of normal-weight children. A total of 44 children (24 girls and 20 boys) aged 5-11 participated in this study. Children played a sorting task while being exposed to a large amount of cookies. Children were tested alone or with an unfamiliar peer or with a sibling. Results indicated that the social condition was related to the participants' energy intake. Children eating with their siblings ate more cookies than did children eating with strangers and also consumed more cookies than did children eating alone. This pattern of results is consistent with previous research in adults indicating that familiarity between co-eaters influence how much one choose to eat. Furthermore, the degree of intake matching was extremely high among strangers, but low and not statistically significant in dyads of siblings. We conclude that matching effect is not ubiquitous and that familiarity affects the level of matching of eating in children.
Salvy, S. J., Kieffer, E., & Epstein, L. H. (2008). Effects of social context on overweight and normal-weight children's food selection. Eating Behaviors, 9, 190-196. doi:10.1016/j.eatbeh.2007.08.001. Link to full text
Although most eating occurs in a social context, the impact of peer influence on child food consumption and selection of healthy and unhealthy snacks has not been the object of systematic experimental study. The present experiment assessed the effects of peer interaction on energy intake and food choices in 18 overweight and 21 non-overweight youth. Participants had access to high and low-calorie food items and were provided with several games as alternatives to eating. On one occasion, participants were tested alone and on another occasion they were tested in dyads with an unfamiliar peer. Consistent with previous results, we found that overweight children ate substantially more when alone than when in the presence of a peer and also more when alone than the lean children in the same condition. Non-overweight youths' food intake was unaffected by the social context. Findings also indicated that the best predictor of whether participants consumed healthy snack foods was if the other youth in the dyad also consumed healthy snack foods. These findings suggest that the presence of peers can influence overweight children's energy intake and also influence healthier food selection in both overweight and non-overweight children.
Salvy, S. J., Bowker, J. W., Roemmich, J. N., Romero, N., Kieffer, E., Paluch, R., & Epstein, L. H. (2008). Peer influence on children's physical activity: An experience sampling study. Journal of Pediatric Psychology, 33, 39-49. doi:10.1093/jpepsy/jsm039. Link to full text
OBJECTIVE: The primary objective was to examine the associations between social context (the presence of peers, friends, and family members) and physical activity intensity for overweight and lean girls and boys.
METHODS: Participants for this study included 10 boys (M = 13.4 years; SD = .8) and 10 girls (M = 13.8 years; SD = .8). Twelve participants were between the 15th and the 85th BMI percentile (eight girls, four boys) and eight youth were at or above the 85th BMI percentile (six boys, two girls). Participants reported on their activity intensity and whether the activity was solitary or with others for seven consecutive days.
RESULTS: Children were more likely to report more intense physical activity when in the company of peers or close friends. Overweight children reported greater physical activity when in the presence of peers than did lean children; however, overweight children also reported more time spent alone.
CONCLUSIONS: Taken together, findings highlight the importance of considering peer relationships in studies of physical activity and childhood "obesity".
Temple, J. L., Legierski, C. M., Giacomelli, A. M., Salvy, S. J., & Epstein, L. H. (2008). Overweight children find food more reinforcing and consume more energy than do nonoverweight children. American Journal of Clinical Nutrition, 87, 1121-1127. Link to full text
BACKGROUND: The reinforcing value of food is a reliable index of motivation to eat and energy intake. Obese adults find food more reinforcing than do nonobese adults.
OBJECTIVE: The present study was designed to assess whether the relative reinforcing value of food differs as a function of weight status in 8-12-y-old children and whether the relative reinforcing value of food differs depending on the types of available nonfood alternatives.
DESIGN: The reinforcing value of pizza (experiment 1) or snack foods (experiment 2) was measured on progressive ratio schedules of reinforcement in nonoverweight and overweight children. Experiment 2 also compared the relative reinforcing value of food and 2 nonfood alternatives: time to spend playing a hand-held video game or time to spend reading magazines or completing word searches or mazes.
RESULTS: In both experiments, overweight children found food more reinforcing and consumed more energy than did their leaner peers. In experiment 2, the relative reinforcing value of food versus sedentary activity was higher in overweight children, but lower in nonoverweight children, regardless of the type of alternative activity available.
CONCLUSIONS: These results show that overweight children find food more reinforcing than do nonoverweight children. This individual difference was replicated in different experiments using different types of foods and food alternatives. These studies provide support for studying food reinforcement as a factor associated with overweight and obesity.
Salvy, S. J., Coelho, J. S., Kieffer, E., & Epstein, L. H. (2007). Effects of social contexts on overweight and normal-weight children's food intake. Physiology & Behavior, 92, 840-846. http://dx.doi.org/10.1016/j.physbeh.2007.06.014. Link to full text
This study investigates the effects of peer influence on the food intake of overweight and normal-weight children. A mixed factorial design was employed, with children's weight status (overweight vs. normal-weight) as a between-subjects factor, and social context (alone vs. group) as a within-subjects factor. A total of 32 children (n=17 overweight and n=15 normal-weight) between the ages of 6-10 years participated in this study. Findings from the random regression model indicated that overweight children ate more when with others than when alone, while in contrast normal-weight ate more with others than they did when alone. Therefore, social context differentially impacts the eating behavior of overweight and normal-weight children. This study underscores differences in responses to the social environment between overweight and non-overweight youths, and suggests that social involvement may be an important tool in treatment and prevention programs for overweight and obesity.
Robinson, J. L., Fuerch, J. H., Winiewicz, D. D., Salvy, S. J., Roemmich, J. N., & Epstein, L. H. (2007). Cost effectiveness of recruitment methods in an obesity prevention trial for young children. Preventive Medicine, 44, 499-503. http://dx.doi.org/10.1016/j.ypmed.2007.03.004. Link to full text
BACKGROUND: Recruitment of participants for clinical trials requires considerable effort and cost. There is no research on the cost effectiveness of recruitment methods for an obesity prevention trial of young children.
METHODS: This study determined the cost effectiveness of recruiting 70 families with a child aged 4 to 7 (5.9+/−1.3) years in Western New York from February 2003 to November 2004, for a 2-year randomized obesity prevention trial to reduce television watching in the home.
RESULTS: Of the 70 randomized families, 65.7% (n=46) were obtained through direct mailings, 24.3% (n=17) were acquired through newspaper advertisements, 7.1% (n=5) from other sources (e.g., word of mouth), and 2.9% (n=2) through posters and brochures. Costs of each recruitment method were computed by adding the cost of materials, staff time, and media expenses. Cost effectiveness (money spent per randomized participant) was US $0 for other sources, US $227.76 for direct mailing, US $546.95 for newspaper ads, and US $3,020.84 for posters and brochures.
CONCLUSION: Of the methods with associated costs, direct mailing was the most cost effective in recruiting families with young children, which supports the growing literature of the effectiveness of direct mailing.
Salvy, S. J., Romero, N., Paluch, R., & Epstein, L. H. (2007). Peer influence on pre-adolescent girls' snack intake: Effects of weight status. Appetite, 49, 177-182. http://dx.doi.org/10.1016/j.appet.2007.01.011. Link to full text
Although most eating occurs in a social context, the effects of peer influence on child eating have not been the object of systematic experimental study. The present study assesses the effects of peer influence on lean and overweight pre-adolescent girls' snack intake as a function of the co-eaters' weight status. The weight status of the participants was varied by studying weight discordant dyads (i.e., one lean and one overweight participant) and weight concordant dyads (i.e., both members of the dyads were either lean or overweight). Results from the random regression model indicate that overweight girls eating with an overweight peer consumed more kilocalories than overweight participants eating with a normal-weight peer. Normal-weight participants eating with overweight peers ate similar amounts as those eating with lean eating companions. The regression model improved when the partners' food intake was entered in the model, indicating that the peers' intake was a significant predictor of participants' snack consumption. This study underscores differences in responses to the social environment between overweight and non-overweight youths.
Vallerand, R. J., Salvy, S. J., Mageau, G. A., Elliot, A. J., Denis, P. L., Grouzet, F. M., & Blanchard, C. (2007). On the role of passion in performance. Journal of Personality, 75, 505-533. doi:10.1111/j.1467-6494.2007.00447.x. Link to full text
The present paper reports two studies designed to test the Dualistic Model of Passion with regard to performance attainment in two fields of expertise. Results from both studies supported the Passion Model. Harmonious passion was shown to be a positive source of activity investment in that it directly predicted deliberate practice (Study 1) and positively predicted mastery goals which in turn positively predicted deliberate practice (Study 2). In turn, deliberate practice had a direct positive impact on performance attainment. Obsessive passion was shown to be a mixed source of activity investment. While it directly predicted deliberate practice (Study 1) and directly predicted mastery goals (which predicted deliberate practice), it also predicted performance-avoidance and performance-approach goals, with the former having a tendency to facilitate performance directly, and the latter to directly negatively impact on performance attainment (Study 2). Finally, harmonious passion was also positively related to subjective well-being (SWB) in both studies, while obsessive passion was either unrelated (Study 1) or negatively related to SWB (Study 2). The conceptual and applied implications of the differential influences of harmonious and obsessive passion in performance are discussed.
Salvy, S. J., Jarrin, D., Paluch, R., Irfan, N., & Pliner, P. (2007). Effects of social influence on eating in couples, friends and strangers. Appetite, 49, 92-99. http://dx.doi.org/10.1016/j.appet.2006.12.004. Link to full text
Previous research indicates that both males and females eat less in the presence of a stranger of the opposite sex than in the presence of a same sex. Another literature shows that people tend to model or matching the amount eaten by others. The extent to which people are eager to inhibit their food consumption or match other's intake is likely to vary as a function of the characteristics of the co-eater. The present study examines how males and females adjust their level of eating as a function of their familiarity with and the gender of their eating companion, using a free-eating paradigm. Findings indicated that both the familiarity between co-eaters and the participants' gender predicted food consumption. Although unfamiliarity suppressed both men's and women's food intakes, the matching effect operated only when a female co-eater was involved. We conclude that the overarching motive (i.e., producing a positive impression) does not necessarily vary substantially across the various gender-familiarity combinations, but that the means or strategies (eating lightly and or matching of intake) by which the person accomplishes it and the strength of the motive vary as a function of the audience. In other words, in some social contexts self-enhancing motives can be served by restricting intake as well as through ingratiatory strategies such as attitudinal or behavioral conformity.
Salvy, S. J., Pierce, W. D., Heth, D. C., & Russell, J. C. (2004). Taste avoidance induced by wheel running: Effects of backward pairings and robustness of conditioned taste aversion. Physiology & Behavior, 82, 303-308. http://dx.doi.org/10.1016/j.physbeh.2004.03.017. Link to full text
Rats repeatedly exposed to a distinctive novel solution (conditioned stimulus, CS) followed by the opportunity to run in a wheel subsequently drink less of this solution. Investigations on this phenomenon indicate that wheel running is an effective unconditioned stimulus (US) for establishing conditioned taste aversion (CTA) when using a forward conditioning procedure (i.e., the US-wheel running follows the CS-taste). However, other studies show that wheel running produces reliable preference for a distinctive place when pairings are backward (i.e., the CS-location follows the US-wheel running). One possibility to account for these results is that rewarding aftereffects of wheel running conditioned preference to the CS. The main objective of the present study was to assess the effects of backward conditioning using wheel running as the US and a distinctive taste as the CS. In a between-groups design, two experimental groups [i.e., forward (FC) and backward conditioning (BC)] and two control groups [CS-taste alone (TA) and CS-US unpaired (UNP)] were compared. Results from this experiment indicated that there is less suppression of drinking when a CS-taste followed a bout of wheel running. In fact, rats in the BC group drank more of the paired solution than all the other groups.
Salvy, S. J., Heth, D. C., Pierce, W. D., & Russell, J. C. (2004). Conditioned taste aversion induced by wheel running: further evidence on wheel running duration. Behavioural Processes, 66, 101-106. doi:10.1016/j.beproc.2004.01.006. Link to full text
Rats given access to a running wheel after drinking a flavored solution subsequently drink less of that liquid. It has been suggested that suppression of intake is the result of conditioned taste aversion (CTA). This study explored whether the magnitude of CTA is related to time in the wheel (i.e., amount of wheel running). During 4 days of conditioning, rats drank an orange liquid for 60 min. Immediately after drinking, experimental rats were transferred to running wheels for either 20 or 60 min. Control animals remained in their home cages. Following the conditioning phase, all rats received a preference test composed of the paired flavored liquid (i.e., orange solution) and water. Rats in both experimental groups (20 and 60 min) decreased their consumption of the orange flavored liquid, but no difference in CTA was found between these groups. Wheel running, whether for 20 or 60 min, suppresses the consumption of a liquid consumed immediately before wheel access. These findings are discussed in terms of discrepancies between CTA induced by wheel running and CTA induced by emetic agents.
Salvy, S. J., Pierce, W. D., Heth, D. C., & Russell, J. C. (2003). Wheel running produces conditioned food aversion. Physiology & Behavior, 80, 89-94. http://dx.doi.org/10.1016/S0031-9384(03)00217-8. Link to full text
Previous investigations of conditioned taste aversion (CTA) induced by wheel running have used flavored liquids such as conditioned stimuli (CSs). Assuming that classical conditioning mediates activity anorexia, it is expected that CTA induced by physical activity should extend to food stimuli. The main purpose of the present experiment was to investigate this possibility. Rats were given a 60-min access to a running wheel [unconditioned stimulus (US)] either before or after being exposed to a novel distinctive flavored food (CS). An additional group had access to running wheels 4 h after receiving the CS food. Results from the present experiment indicate that regimented and contingent periods of wheel running decrease consumption of a food available before wheel running in nondeprived rats.
Salvy, S. J., & McCargar, L. (2002). Nutritional interventions for individuals with bulimia nervosa. Eating and Weight Disorders, 7, 258-267. doi:10.1007/BF03324971. Link to full text
Many physical and psychological effects of bulimia nervosa are caused by the patient's partial starvation and chaotic nutritional cycle. Attention should thus be initially directed to correcting nutritional deficiencies and abnormal eating patterns, and providing dietary counselling. Nevertheless, very little has been written about the nutritional management of this eating disorder. Nutritional counselling for bulimia patients is reviewed in this paper. Current knowledge about nutritional therapy and its efficacy, goals and objectives is presented, along with recommendations used in treatment programmes. Lastly, the key steps of nutritional management are summarised.
Salvy, S. J., Pierce, W. D., Heth, D. C., & Russell, J. C. (2002). Pre-exposure to wheel running disrupts taste aversion conditioning. Physiology & Behavior, 76, 51-56. http://dx.doi.org/10.1016/S0031-9384(02)00687-X. Link to full text
When rats are given access to a running wheel after drinking a flavored solution, they subsequently drink less of that flavor solution. It has been suggested that running produces a conditioned taste aversion (CTA). This study explored whether CTA is eliminated by prior exposure to wheel running [i.e., unconditioned stimulus (UCS) pre-exposure effect]. The rats in the experimental group (UW) were allowed to wheel run for 1 h daily for seven consecutive days of pre-exposure. Rats in the two other groups had either access to locked wheels (LW group) or were maintained in their home cages (HC group) during the pre-exposure days. All rats were then exposed to four paired and four unpaired trials using a "ABBAABBA" design. Conditioning trials were composed of one flavored liquid followed by 60-min access to wheel running. For the unpaired trials, rats received a different flavor not followed by the opportunity to run. All rats were then initially tested for water consumption followed by tests of the two flavors (paired or unpaired) in a counterbalanced design. Rats in the UW group show no CTA to the liquid paired with wheel running, whereas LW and HC groups developed CTA. These results indicate that pre-exposure to wheel running (i.e., the UCS), eliminates subsequent CTA.