Influence of sedentary, social, and physical alternatives on food reinforcement

Daily social resources as a buffer against stress eating and its consequences

OBJECTIVE

Eating in response to stress can become habitual and have long-term consequences for weight gain, but little research has explored what may help break stress-eating cycles. We examined daily social resources as potential protective factors against daily stress eating and eventual weight gain.

METHOD

In Study 1 (N = 1,264), we assessed stress-eating tendencies, body mass index (BMI) and waist-to-hip ratio (WHR) at baseline, receipt of emotional support over 8 days (9,649 reports), and tracked BMI/WHR after about 10 years. We examined the average likelihood of receiving emotional support as a moderator of the link between stress eating and BMI/WHR at the follow-up. In Study 2 (N = 536; 10,288 reports), we assessed stress-eating status and BMI at baseline, social responsiveness (feeling that others are caring), and stress-eating behavior over 24 days and tracked BMI a year later. We examined if social responsiveness moderates stress-eaters' daily stress-eating behaviors and changes in BMI.

RESULTS

In Study 1, stress eating predicted increases in BMI and WHR at the 10-year follow-up but not among individuals who were more (vs. less) likely to receive emotional support in daily life. In Study 2, stress eaters tended to report more daily stress-eating behaviors compared to nonstress eaters, but such tendency was attenuated on days they perceived high (vs. low) levels of social responsiveness. Stress eating did not predict BMI at the 1-year follow-up.

CONCLUSIONS

These observational findings suggest that social resources in daily lives may have long-term benefits for stress eaters, potentially by reducing their everyday stress eating. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Sources of Environmental Reinforcement and Engagement in Health Risk Behaviors Among a General Population Sample of US Adults

Research supports the premise that greater substance use is associated with fewer sources of environmental reinforcement. However, it remains unclear whether types of environmental reinforcement (e.g., social or work) may differentially influence use. This study tested the association between types of environmental reinforcement and engagement in multiple health risk behaviors (alcohol use, binge eating, and nicotine use). Cross-sectional data were collected from a general population sample of US adults (N = 596). The Pleasant Events Schedule (PES) was used to measure sources of reinforcement. Exploratory structural equation modeling (ESEM) characterized different areas of environmental reinforcement and correlations with alcohol consumption, binge eating, and nicotine use. A four-factor structure of the PES demonstrated a conceptually cohesive model with acceptable fit and partial strict invariance. Social-related reinforcement was positively associated with alcohol consumption (β = 0.30, p < 0.001) and binge eating (β = 0.26, p < 0.001). Work/school-related reinforcement was negatively associated with binge eating (β = -0.14, p = 0.006). No areas of reinforcement were significantly associated with nicotine use (p values = 0.069 to 0.755). Social-related activities may be associated with engagement in multiple health risk behaviors (more binge eating and alcohol use), whereas work/school-related activities may be preventative against binge eating. Understanding these relationships can inform prevention efforts targeting health risk behaviors.

Maternal caregiving stress and metabolic health: Sexual activity as a potential buffer

Chronic stress lead to dysregulation of metabolic hormones, creating risk for obesity and type 2 diabetes. Based on previous work suggesting the potential for sexual activity to relieve psychological stress and reduce stress-related neuroendocrine activity, the present research explored sexual activity as a protective factor. We focused on chronic stress in the form of caregiving stress, comparing premenopausal mothers of a child with an autism spectrum disorder vs. a neurotypical child, in relation to metabolic hormones - insulin (and insulin resistance as assessed by HOMA), leptin, and ghrelin. Then, we explored the moderating role of sexual activity. Our results showed that high-stress mothers showed higher levels of insulin, insulin resistance, and lower levels of ghrelin compared to low-stress mothers. However, sexual activity modulated these associations such that among mothers who were sexually active (as coded from their daily diaries), no significant differences in these outcomes were observed between groups. This buffering effect of sexual activity was distinguishable from the buffering effect of physical activity and independent of global relationship satisfaction. Together, our findings provide novel evidence supporting the potential protective effects of sexual activity from chronic stress-related metabolic disease risk.

A psychobioecological model to understand the income-food insecurity-obesity relationship

Food insecurity, defined by unpredictable access to food that may not meet a person's nutritional needs, is associated with higher BMI (kg/m2) and obesity. People with food insecurity often have less access to food, miss meals and go hungry, which can lead to psychological and metabolic changes that favor energy conservation and weight gain. We describe a conceptual model that includes psychological (food reinforcement and delay discounting) and physiological (thermic effect of food and substrate oxidation) factors to understand how resource scarcity associated with food insecurity evolves into the food insecurity-obesity paradox. We present both animal and human translational research to describe how behavioral and metabolic adaptations to resource scarcity based on behavioral ecology theory may occur for people with food insecurity. We conclude with ideas for interventions to prevent or modify the behaviors and underlying physiology that characterize the income-food insecurity-obesity relationship.

Associations Between Daily Activities, Stress, and Sleep Among Adults During the COVID-19 Pandemic

The COVID-19 pandemic introduced lifestyle changes that appeared to impact adults' engagement in health-promoting activities. Researchers observed increased stress, sleep problems, and sedentary activity, and decreased physical activity during the pandemic. This secondary analysis examined the frequency that adults engaged in different daily activities and links between activity types, stress, and sleep during the pandemic. Fifty-three adults completed a single online survey in January 2021 where they reported demographics, COVID-19 pandemic experiences, daily activities, stress, and sleep. Sum scores were calculated to indicate total frequency of different activity types. Regressions were used to examine whether the frequency of different activity types predicted sleep duration and stress. There was a trend-level relationship between the frequency of activities done outdoors and stress scores, such that doing outdoor activities more often was linked with less stress (P = .098). Higher income also tended to be linked with more stress (P = .053), as did younger age (P = .028). When restricting the outdoor activity variable to physical outdoor activities only, the relationship with stress became significant (P = .013). These results suggest that engaging in physical activity outdoors may reduce stress during the COVID-19 pandemic.

Effects of Episodic Memory Recall on Reinforcing Value of Physical Activity

OBJECTIVE

Many people prefer a sedentary versus an active lifestyle and have difficulty completing sufficient physical activity to improve health. While exercise can be a powerful reinforcer for some people, many prefer to be sedentary. The relative reinforcing value of physical activity (RRVPA) is influenced by a person's learning history with positive experiences strengthening the motivation to be active. Episodic memories may be critical to determining RRVPA, or RRV of different types of positive behaviors.

METHOD

As a potential way to increase RRVPA we examined if recalling a positive episodic memory would affect RRVPA. One hundred and thirty seven adult participants completed measures of reinforcement history and memory functions and then recalled a single positive episode of either a physical activity or of a cognitively enriching activity, rated subjective memory qualities, and completed tasks to measure the RRV of both types of activity.

RESULTS

Recalling a positive episodic memory increased RRV for the respective activity, and changes in RRVPA were moderated by how much the memory satisfies a basic psychological need.

CONCLUSIONS

This research demonstrates the impact of episodic memory on RRVPA, which could be leveraged to aid behavior change efforts.

Effects of a randomized controlled hiking intervention on daily activities, sleep, and stress among adults during the COVID-19 pandemic

BACKGROUND

Physical activity promotes health, and physical activity done outdoors in nature may be particularly beneficial. We conducted two randomized studies to examine the implementation of a winter hiking intervention and whether this intervention affected activity choices and aspects of well-being during the COVID-19 pandemic.

METHODS

Convenience samples of adults (n = 53; n = 51) were recruited into two different randomized studies in 2021 and 2022 respectively. Participants completed online surveys at baseline and 6 and 11-12 weeks later. Participants were randomized to a study group (intervention or control) shortly after the baseline assessments. In both studies, the intervention group received free access to a regional winter hiking challenge. In the second study, we also provided winter traction cleats to this group to facilitate engagement in the hiking challenge. Descriptive statistics were used to summarize intervention implementation, including participants' engagement in challenge hikes. Repeated measures ANOVA models were used to test intervention effects on key outcome variables, including hiking frequency via the Pleasant Activities List, stress via the Perceived Stress Scale, and sleep duration via the Pittsburgh Sleep Quality Index.

RESULTS

In the first study, the intervention group's engagement in challenge hikes was low (38.5%); reported barriers included access to winter hiking equipment. In the second study, when winter traction cleats were provided, engagement in the intervention was higher, and the intervention increased hiking frequency and improved sleep. There were no significant intervention effects on stress, but the direction of effects was in the expected direction.

CONCLUSIONS

Results highlight some potential positive impacts of this intervention designed to facilitate access to winter hiking. Future research could examine whether effects are stronger in a larger sample, in which additional barriers to engagement are addressed.

TRIAL REGISTRATION

This study was registered at clinicaltrials.gov on 28/12/2020 prior to participant enrollment (NCT04685681), https://clinicaltrials.gov/ct2/show/NCT04685681 .

The Effect of Financial Scarcity on Reinforcer Pathology: A Dyadic Developmental Examination

This study investigated the effects of experimentally manipulated scarcity on the reinforcing value of food (RRVfood) and delay discounting (DD), which, together, create reinforcer pathology (RP) among parents and offspring. A stratified sample of 106 families (53 parent/child aged 7−10 dyads & 53 parent/adolescent aged 15−17 dyads) from high- and low-income households visited our laboratory for three appointments. Each appointment included an experimental manipulation of financial gains and losses and DD and RRV tasks. The results showed that, regardless of food insecurity or condition, children had greater RP (β = 1.63, p < 0.001) than adolescents and parents. DD was largely unaffected by acute scarcity in any group, but families with food insecurity had greater DD (β = −0.09, p = 0.002) than food-secure families. Food-insecure parents with children responded to financial losses with an increase in their RRVfood (β = −0.03, p = 0.011), while food-secure parents and food-insecure parents of adolescents did not significantly change their responding based on conditions. This study replicates findings that financial losses increase the RRVfood among adults with food insecurity and extends this literature by suggesting that this is strongest for parents of children.

Reinforcer pathology's alternative reinforcer hypothesis: A preliminary examination

BACKGROUND AND OBJECTIVE

The novel theory of Reinforcer Pathology states that the temporal window of integration, measured by delay discounting (DD), determines the value of reinforcers. Based on the Reinforcer Pathology theory, the valuation of alternative reinforcers is positively associated with the length of the temporal window (negatively with rates of discounting). The objective of this article is to test the Reinforcer Pathology theory by reanalyzing data from a prior report (Carr & Epstein, 2018) in order to examine the association between the reinforcing value of alternative reinforcement and the length of the measured temporal window.

METHOD

Participants (N = 250) who completed an adjusting delay discounting task and the Pleasant Events Schedule (PES) were included in the study. PES provides a measurement of a reinforcement score (a cross-product of PES measures of frequency and pleasantness) for 45 noneating alternative activities. Analysis of Variance and Spearman product-moment correlations were completed.

RESULTS

Delay discounting was significantly positively correlated with sedentary reinforcement and significantly negatively correlated with cognitively enriching activities. A significant interaction was observed in the preference for between food and cognitive-enriching context as a function ln(k) in predicting the cognitive-enriching activity class. Nonsignificant relationships were also observed with the correlation of delay discounting to the reinforcement of social and physical activities.

CONCLUSIONS

These findings provide initial support for Reinforcer Pathology theory and indicate that the temporal window over which reinforcers are integrated may be a factor contributing to a preference for some healthy or unhealthy alternative reinforcers. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Sensitization of the reinforcing value of high energy density foods is associated with increased zBMI gain in adolescents

Background/Objectives

Characterizing behavioral phenotypes that predict increased zBMI gain during adolescence could identify novel intervention targets and prevent the development of obesity. The purpose of this study was to determine if sensitization of the relative reinforcing value (RRV) of high (HED) or low energy density (LED) foods predicts adolescent weight gain trajectories. A secondary aim was to test the hypothesis that relationships between sensitization of the RRV of food and weight change are moderated by delay discounting (DD).

Subjects/Methods

We conducted a prospective, longitudinal cohort study in 201 boys and girls with an average zBMI of 0.4, who began the study between the ages of 12 and 14 years and completed the study 2 years later. Participants completed five laboratory visits where the RRV of HED and LED, and DD were assessed at a baseline (visits 1, 2, and 4) and then RRV was measured again after participants consumed a portion of the same HED and LED food for 2 weeks (visits 3 and 5; order counterbalanced). Increases (>1) in the RRV from baseline to post-daily intake were categorized as “sensitization” and decreases (≤1) were categorized as “satiation.” Participants returned to the laboratory for follow-up visits at 6, 15, and 24 months to have height and weight taken and to complete additional assessments.

Results

Sensitization to HED food was associated with a greater zBMI change over time (β = 0.0070; p = 0.035). There was no impact of sensitization to LED food or interaction between sensitization to HED and LED food on zBMI change and no moderation of DD on the relationship between HED sensitization and zBMI change (all p > 0.05).

Conclusion

Our prior work showed that sensitization to HED food is cross-sectionally associated with greater zBMI. This study extends this work by demonstrating that sensitization to HED food prospectively predicts increased zBMI gain over time in adolescents without obesity. Future studies should determine if sensitization can be modified or reduced through behavioral intervention.

Trial registration

Clinicaltrials.gov: NCT04027608.

Food reinforcement and habituation to food are processes related to initiation and cessation of eating

An individual bout of eating involves cues to start eating, as well as cues to terminate eating. One process that determines initiation of eating is food reinforcement. Foods with high reinforcing value are also likely to be consumed in greater quantities. Research suggests both cross-sectional and prospective relationships between food reinforcement and obesity, food reinforcement is positively related to energy intake, and energy intake mediates the relationship between food reinforcement and obesity. A process related to cessation of eating is habituation. Habituation is a general behavioral process that describes a reduction in physiological or affective response to a stimulus, or a reduction in the behavioral responding to obtain a stimulus. Repeated exposure to the same food during a meal can result in habituation to that food and a reduction in consumption. Habituation is also cross-sectionally and prospectively related to body weight, as people who habituate slower consume more in a meal and are more overweight. Research from our laboratory has shown that these two processes independently influence eating, as they can account for almost 60% of the variance in ad libitum intake. In addition, habituation phenotypes show reliable relationships with reinforcing value, such that people who habituate faster also find food less reinforcing. Developing a better understanding of cues to start and stop eating is fundamental to understanding how to modify eating behavior. An overview of research on food reinforcement, habituation and food intake for people with a range of weight status and without eating disorders is provided, and ideas about integrating these two processes that are related to initiation and termination of a bout of eating are discussed.

Sensitization of the reinforcing value of food: a novel risk factor for overweight in adolescents

Background and Objectives

The relative reinforcing value (RRV) of food is associated with increased energy intake and obesity and increases in RRV of food after repeated intake (sensitization) are related cross-sectionally and prospectively to higher BMI in adults. We examined the factors, such as delay discounting (DD), associated with sensitization of RRV of high energy density (HED) and low energy density (LED) food and how sensitization relates to zBMI in adolescents. We hypothesized that sensitization to HED food would be positively associated with zBMI, that sensitization to LED food would be negatively associated with zBMI, that DD would be associated with HED sensitization, and that LED sensitization and DD would moderate the relationships between HED sensitization and zBMI.

Subjects and Methods

A population-based sample of 207 adolescents without obesity, aged 12 – 14 years was studied from June 2016 – March 2019. The RRV of LED and HED foods were measured before and after two weeks of daily consumption along with zBMI and other potential factors related to eating and weight, including dietary restraint, hunger, food liking, and delay discounting (DD). Hierarchical regression models were used to determine the associations between these factors and sensitization and zBMI. We also examined LED sensitization and DD as potential moderators of the relationship between sensitization and zBMI.

Results

As hypothesized, dietary restraint and sensitization to HED food were associated with greater zBMI. Contrary to our original hypotheses, DD was not associated with sensitization, there was no relationship between sensitization to LED food and zBMI and neither LED sensitization or DD moderated the relationship between HED sensitization and zBMI.

Conclusions

Sensitization to repeated intake of HED food was associated with higher zBMI in adolescents without obesity. Sensitization may be a novel behavioral phenotype that may relate to overweight in youth.

Development of a measure of the relative reinforcing value of food versus parent-child interaction for young children

The relative reinforcing value (RRV) of food captures individual differences in the motivation to eat and is associated with weight status among infants, children, and adults. Currently, there is no concurrent measure of the RRV of food versus a non-food alternative for 4-to-5-year-old children. The present study aimed to develop and validate a measure of the RRV of food versus time spent interacting with a parent in the context of reading among 4-to-5-year-old children. The first phase of the study involved an online survey. Parents of 4-to-5 year olds (n = 102) reported their children's consumption frequency and liking for thirty-six snack foods. A priori criteria were used to identify snacks that were well-liked and served at least sometimes for use in the subsequent laboratory study. Then, a validation study was conducted in the laboratory to examine the construct validity of the finalized RRV task. Thirty-one parent-child dyads completed a laboratory visit, in which children's RRV of food versus time spent reading with a parent was measured concurrently on a progressive ratio reward schedule. Linear regression was used to assess validity of the task. Children's RRV of food positively and significantly predicted BMI z-scores among children with complete data (B = 0.41, p < 0.05, n = 28). Maximum schedules reached for food also positively and significantly predicted BMI z-scores (B = 0.30, p < 0.05). The relationship between maximum schedules reached for parent-child reading and BMI z-scores was in the expected direction, but this relationship was non-significant. Results support the validity and feasibility of the RRV paradigm used in the present study. Future research could continue to examine the measurement properties of this paradigm, as well as the potential for positive parent-child interactions to serve as a novel alternative to food.

Environmental enrichment reduces food seeking and taking in rats: A review

Environmental enrichment (EE) for rodents is generally defined as providing subjects with an environment enhanced with access to conspecifics, novel and tactile stimuli, and in many preparations, more space. EE exposure, in particular as an "intervention" in adult rodents, decreases food and drug seeking and taking. This review focuses on the reduction of sucrose seeking and taking in rats assessed in operant-based procedures. The operant-based model provides a means to evaluate addiction-related behaviors. Findings using the model might translate to clinically-relevant addiction behaviors directed towards both drugs and food. Both overnight (acute) and one month (chronic) EE effects on behavior are described, including a recent evaluation of the persistence of EE effects following its removal. EE effects on neurobiology related to sucrose seeking using the model are outlined, with a special emphasis on meso-cortico-limbic terminals. Overall, our working hypothesis for how EE reduces sucrose seeking and taking is that EE alters processing of incentive valence. This may also be accompanied by changes in learning and affect. Anti-seeking and anti-taking effects of EE have translational implications for the prevention and treatment of both drug addiction and food-focused behaviors ("food addiction").

Choice is relative: Reinforcing value of food and activity in obesity treatment

Persons with obesity find high-energy-dense food and sedentary behaviors highly reinforcing. Diets and exercise programs deprive individuals of many favorite foods and activities, which can counterproductively heighten their value and lead to relapse. Since the value of reinforcers depend on the alternatives available, one approach to reducing food and sedentary activity reinforcement is to build healthy alternative reinforcers. Current behavioral treatment programs for children and adults do not attempt to build alternative reinforcers as substitutes for unhealthy behaviors to reduce the impact of food or activity deprivation on the motivation to eat or be inactive. A goal of the next generation of obesity treatment programs should focus on development of healthy behaviors as reinforcers so that people will be motivated to engage in them. This article provides an overview of relationships among reinforcers, how understanding substitutes and complements can influence eating and activity, and how enriching a person's environment and providing choice architecture can enhance weight control. Ideas for translation of these basic behavioral economic principles to obesity treatment programs are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Non-food rewards and highly processed food intake in everyday life

Reducing intake of highly processed, energy-dense food may prevent chronic disease. One proposed intervention strategy for reducing intake of these foods is to increase non-food reward experiences (e.g., music, socializing, art) in their place. However, research supporting this strategy has yet to establish temporal order between non-food reward experiences and highly processed food intake, and has yet to test mediators. The current study sought to build upon this literature with an ambulatory electronic diary study wherein the time-specific associations between non-food reward experiences and highly processed food intake were observed. A sample of 84 young adults reported on multiple types of non-food reward experiences and highly processed food intake hourly for two weekdays and two weekend days through an application on their personal electronic devices. Time-lagged analysis was employed to predict the odds of highly processed food intake in the following hour from non-food rewards experienced in the current hour. Secondary (e.g., receiving positive social feedback) and hedonic (e.g., viewing pleasant images) non-food reward experiences in the current hour predicted greater instead of lower odds of highly processed food intake in the following hour. These associations were mediated by increased subjective pleasure. Purely eudaimonic (e.g., affirming values), social (e.g., cooperating with others), and primary (e.g., having sex) reward experiences generally did not predict odds of highly processed food intake in the following hour. These results suggest that-at least for young adults-many non-food reward experiences may fail to reduce highly processed food intake, and some may even backfire. A different intervention strategy targeting reward processes implicated in highly processed food intake (e.g., interfering with conditioned learned associations) may prove a more promising avenue for improving physical health.

Food and non-food reinforcement among pregnant women

Excessive gestational weight gain (GWG) in pregnancy may be driven in part by greater motivation to eat, and studying the relative reinforcing value of food versus non-food commodities may provide insight into factors important for excessive GWG. This study was a cross-sectional examination of the relationship between women meeting the Institute of Medicine (IOM) guidelines for GWG and the relative reinforcing value of food vs. non-food commodities during pregnancy. Two-hundred and thirty-three pregnant women (1st trimester, n = 44; 2nd trimester, n = 105; 3rd trimester, n = 84), aged 18-40, were recruited via a crowdsourcing platform and completed an online survey. Relative food reinforcement (RRV_food), relative non-food activity reinforcement (RRV_active) and relative non-food cognitively enriching activity reinforcement (RRV_cognitive) were measured by a questionnaire at the point of contact. Self-reports of gestational age and weight gain during pregnancy were collected. The relationship between food and non-food reinforcement was assessed based on IOM classifications for weight gain during pregnancy. After adjustment for women's education level and parity, higher RRV_food (p = 0.036) and lower RRV_cognitive (p = 0.040) responses were associated with greater GWG. Food reinforcing ratio (FRR) analysis was then conducted to systematically examine the effect of non-food behaviors on GWG when food reinforcement was accounted for. Women who gained below the IOM weight gain guidelines had significantly higher FRR_cognitive than those gaining above (p = 0.013), indicating cognitively enriching activities may better compete with food among pregnant women. Interventions that help to increase the reinforcing value of cognitively enriching activities may be a new avenue to regulate eating to minimize GWG.

Binary components of food reinforcement: Amplitude and persistence

BACKGROUND

Demand curves provide an index of how reinforcing a food is. Research examining the latent structure of alcohol and tobacco reinforcement identified two underlying components of reinforcement, amplitude and persistence. No research has assessed latent structure of food reinforcement and how these factors are related to BMI.

SUBJECTS AND METHODS

Participants were 297 adults from two studies that completed food purchasing tasks to assess the following measures of relative reinforcing efficacy (RRE) of food: intensity (Q₀): purchases made when the food was free or of very minimal price, O_max: maximum expenditure (purchases*price), P_max: price point where maximum expenditure was observed, breakpoint: first price where 0 purchases are made, and demand elasticity (α): quantitative non-linear relationship between purchasing and price. Principal components analysis was used to examine the factor structure of RRE for food across samples and types of food.

RESULTS

Both studies revealed two factor solutions, with P_max, O_max, breakpoint and α loading on factor 1 (persistence) and intensity (Q₀) loading on factor 2 (amplitude) across both high and low energy dense foods. Persistence reflects an aggregate measure of price sensitivity and amplitude reflects the preferred volume of consumption (how long vs. how much). The two factors accounted for between 91.7 and 95.4% of the variance in food reinforcement. Intensity for high energy dense foods predicted BMI for both studies (r = 0.18 and r = 0.22, p's < 0.05).

CONCLUSIONS

The latent factor structure was similar across two significantly different independent samples and across low and high energy dense snack foods. In addition, the amplitude of the demand curve, but not persistence, was related to BMI. These results suggest specific aspects of food reinforcement that can be targeted to alter food intake.