Translational science approaches for food insecurity research.

Food insecurity is a pervasive problem that impacts health and well-being across the lifespan. The human research linking food insecurity to poor metabolic and behavioral health outcomes is inherently correlational and suffers from a high degree of variability both between households and even within the same household over time. Further, food insecurity is impacted by societal and political factors that are largely out of the control of individuals, which narrows the range of intervention strategies. Animal models of food insecurity are being developed to address some of the barriers to mechanistic research. However, animal models are limited in their ability to consider some of the more complex societal elements of the human condition. We believe that understanding the role that food insecurity plays in ingestive behavior and chronic disease requires a truly translational approach, and that understanding the health impacts of this complex social phenomenon requires understanding both its psychological and physiological dimensions. This brief review will outline some key features of food insecurity, highlighting those that are amenable to investigation with controlled animal models and identifying areas where integrating animal and human studies can improve our understanding of the psychological burden and health impacts of food insecurity. In the interest of brevity, this review will largely focus on food insecurity in the United States, as the factors that contribute to food insecurity vary considerably across the globe.

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.

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 (ß = 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.

Eating and Physical Activity Patterns in Day and Night Shift EMS Clinicians.

Objective: EMS clinicians work in shifts to provide 24-hour care. Shift work is linked with metabolic disease and over 70% of EMS clinicians report having overweight or obesity. Inability to store food in their vehicles combined with limited overnight dining establishments, and unpredictable job demands leads to reliance on convenience and fast foods. The objective of this study was to describe the eating and physical activity patterns among EMS clinicians on days on and off shift.Methods: EMS clinicians throughout the United States participated in a study involving four 24-hour monitoring periods. Participants wore activity monitors to measure physical activity level and remote food photography was used to collect dietary data on two work days and two days off. Repeated measures analysis of variance was conducted to compare energy and macronutrient intake and activity levels in day and night workers on and off shift.Results: We analyzed data from 39 EMS clinicians (29.7 + 8.5yrs old). Controlling for sex, those working night shifts consumed more kilocalories (p=.037) and total fat (p=.043) compared to day shift workers. Night shift workers had fewer steps (p = 0.045), more sedentary time (p = 0.053), and less moderate activity (p = 0.037) during a shift compared to day workers.Conclusion: Among EMS clinicians, night shift is associated with greater energy intake, and decreased physical activity during shifts. This may contribute to positive energy balance and weight gain overtime, increasing risk for metabolic disease.

The effect of food insecurity and stress on delay discounting across families: a COVID-19 natural experiment.

BACKGROUND: Delay Discounting is the extent to which one prioritizes smaller immediate rewards over larger, delayed rewards. The ability to prospect into the future is associated with better health decision-making, which suggests that delay discounting is an important intervention target for the prevention and treatment of chronic disease. Delay discounting decreases throughout development and stressful experiences, particularly those that accompany poverty, may influence this developmental trajectory. The current study leveraged the COVID-19 pandemic and resulting economic downturn as a natural experiment to understand how changes in food insecurity and psychological stress may associated with changes in delay discounting among parents, adolescents, and children. METHODS: A stratified cohort of families (N = 76 dyads), established prior to the initial pandemic lockdowns, were asked to complete a follow-up survey in the summer of 2020, during reopening. Thirty-seven (49%) families had an older adolescent (aged 15 - 18 years) in the study and 39 (51%) had an elementary aged child (aged 7 - 12 years) in the follow-up study. Both data collection points included measurements of economic position, psychological stress, food security status, and delay discounting. RESULTS: The results showed that pandemic food insecurity was associated with greater stress among parents (ß = 2.22, t(65.48) = 2.81, p = 0.007). Parents, Adolescents, and children significantly differed in their response to psychological stress during the pandemic (ß = -0.03, t(102.45) = -2.58, p = 0.011), which was driven by a trend for children to show greater delay discounting associated with an increase in psychological stress during the pandemic (ß = -0.01, p = 0.071), while adolescents and parents showed no change. CONCLUSIONS: These findings add to the evidence that food insecurity is uniquely stressful among parents with no effects on delay discounting. Despite this, we found no evidence that food insecurity was stressful for child or adolescents. A trend in our data suggested that childhood, as compared with adolescence, may be an important developmental period for the association between stress and delay discounting. Future research should continue the longitudinal investigation of childhood stress and the developmental trajectory of delay discounting to ascertain how these effects may persist in adulthood.

Consumption of a Variety of Vegetables to Meet Dietary Guidelines for Americans' Recommendations Does Not Induce Sensitization of Vegetable Reinforcement Among Adults with Overweight and Obesity: A Randomized Controlled Trial.

BACKGROUND: Food reinforcement, or the motivation to obtain food, can predict choice and consumption. Vegetable consumption is well below recommended amounts for adults, so understanding how to increase vegetable reinforcement could provide valuable insight into how to increase consumption. OBJECTIVES: We sought to determine whether daily consumption of the Dietary Guidelines for Americans (DGA) recommendations for vegetable intake induces sensitization of vegetable reinforcement in adults with overweight and obesity. METHODS: Healthy adults with a BMI ≥ 25 kg/m2 who consumed ≤1 cup-equivalent of vegetables/day were randomly assigned to a vegetable intervention (VI; n = 55) or an attention control (AC; n = 55) group. The VI consisted of the daily provision of vegetables in the amounts and types recommended by the DGA (∼270 g/day) for 8 weeks. Participants were followed for an additional 8 weeks to assess sustained consumption. Compliance was measured weekly by resonance Raman light-scattering spectroscopy (RRS). Vegetable reinforcement was tested at weeks 0, 8, 12, and 16 using a computer choice paradigm. RESULTS: In the VI group, RRS intensity increased from week 0 to 8 (from 22,990 to 37,220), returning to baseline by week 16 (27,300). No change was observed in the AC group. There was no main effect of treatment (P = 0.974) or time (P = 0.14) and no treatment x time interaction (P = 0.44) on vegetable reinforcement. There was no moderating effect of sex (P = 0.07), age (P = 0.60), BMI (P = 0.46), delay discounting (P = 0.24), 6-n-propylthiouracil taster status (P = 0.15), or dietary disinhibition (P = 0.82) on the change in vegetable reinforcement. CONCLUSIONS: These findings suggest no effects of the provision of a variety of vegetables to meet DGA recommendations for 8 weeks on vegetable reinforcement and highlight the difficulty in increasing vegetable consumption in adults. This trial was registered at clinicaltrials.gov as NCT02585102.

Having less and wanting more: an investigation of socioeconomic status and reinforcement pathology.

BACKGROUND: In the United states obesity and socioeconomic status (SES), or one's standing in society based on income, education, and/or occupation, are strongly associated. The mechanisms for this relationship may include having high levels of motivation to get food (reinforcing value of food; RRV) and low levels of inhibitory control (delay discounting; DD) which, when combined, is referred to as reinforcement pathology (RP). We sought to examine the relationships among multiple measures of household SES, RP, and age-adjusted body mass index (zBMI) among adolescents. METHODS: These data were collected as part of ongoing longitudinal study of risk factors for obesity in 244 adolescents. The adolescents and one parent/guardian had height and weight measured and completed surveys. The adolescents completed an adjusting amount DD task and a computer-based RRV task. Analyses consisted of correlations among measures of SES and RRV, DD, and BMI z-scores. In the case of significant associations, multiple regression models were created with theoretically informed covariates. RESULTS: Household income, parent/guardian education, parent/guardian occupation, and food insecurity status were all related to one another. Among the adolescents, a significant portion of the variance in RRV was accounted for by household income after controlling for covariates. For DD, it was parent/guardian education that was most associated after controlling for covariates. CONCLUSION: When low income and low parent/guardian education occur together, there may be an increased risk of RP. Separately, food insecurity was predictive of higher parent/guardian BMI. Future research should continue to explore the effects of low income and parent/guardian education on RP among youth by examining them over time.

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 to 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.

The association of food insecurity with the relative reinforcing value of food, BMI, and gestational weight gain among pregnant women.

OBJECTIVE: Food insecurity is associated with obesity among adults. During pregnancy, food insecurity increases obesity risk among mothers and infants. This study investigated the association of food security with pre-pregnancy body mass index (BMI), gestational weight gain (GWG) adequacy to date, and the relative reinforcing value (RRV) of food during pregnancy. METHODS: This secondary data analysis examined 258 pregnant women (mean gestational age = 21.21 ± 10.21 weeks) surveyed on pre-pregnancy weight, height, pregnancy due date and GWG to date, current diagnoses related to eating and pregnancy, and demographics. The survey also assessed current food security and RRV of meals, snacks, cognitive activities, and active activities. BMI was calculated from pre-pregnancy height and weight (kg/m2). Gestational weight gain adequacy to date was derived from the Institute of Medicine guidelines. Multivariable linear regression models were used to examine the relation of food security with pre-pregnancy BMI and RRVs of foods/activities. The relation between food security and GWG adequacy to date was examined using multinomial regression models. RESULTS: Lower food security was related to both greater pre-pregnancy BMI (ß = 0.60, p < .001) and greater RRV of snack foods (ß = 3.46, p < .05), after controlling for covariates. Lower food security was also related to GWG to date below recommended levels (OR = 1.25, p < .05). CONCLUSIONS: Food insecurity is related to higher relative food reinforcement during pregnancy, and greater pre-pregnancy weight status. Future research should replicate and extend these findings by assessing them longitudinally to better evaluate the directions of these relationships.

The relationships between eating disorder pathology and relative reinforcing value of food, delay discounting, and related constructs in adolescents.

Food is a primary reinforcer that motivates behavior in the absence of learning or conditioning. Both the relative reinforcing value (RRV) of food and delay discounting are associated with weight status. While dietary restraint and disinhibition have been shown to influence the RRV of food, limited work has examined the relationships between eating disorder pathology and RRV of food and delay discounting. Therefore, the purpose of this study was to examine how eating disorder pathology predicts RRV of food, proportion of food consumed, delay discounting, reinforcement pathology (i.e., high motivation to eat and high delay discounting), and sensitization of high energy dense food (HED; i.e., increases in RRV of HED food after daily repeated exposure). Participants were 167 adolescents ages 12-14 without obesity participating in a longitudinal study examining predictors of weight change who completed a series of laboratory assessments assessing the RRV of food of HED food, delay discounting, reinforcement pathology, sensitization of HED food, and a questionnaire assessing eating disorder pathology. Eating disorder pathology was not related to the RRV of food or delay discounting, but did predict reinforcement pathology and the sensitization of HED food. When explored by weight status, these relationships were only observed for those with overweight. There were no other significant relationships for either adolescents with normal weight or overweight. Given that weight status appeared to moderate some of the relationships between eating disorder pathology and reinforcement-related constructs, future work should examine how reinforcement pathology and eating disorder pathology are related to changes in weight status over time.

Systematic Review and Meta-analysis of the Effects of Caffeine in Fatigued Shift Workers: Implications for Emergency Medical Services Personnel.

BACKGROUND: Emergency Medical Services (EMS) workers may experience fatigue as a consequence of shift work. We reviewed the literature to determine the impact of caffeine as a countermeasure to fatigue in EMS personnel and related shift workers. METHODS: We employed the GRADE methodology to perform a systematic literature review and search multiple databases for research that examined the impact of caffeine on outcomes of interest, such as patient and EMS personnel safety. For selected outcomes, we performed a meta-analysis of pooled data and reported the pooled effect in the form of a Standardized Mean Difference (SMD) with corresponding 95% confidence intervals. RESULTS: There are no studies that investigate caffeine use and its effects on EMS workers or on patient safety. Four of 8 studies in shift workers showed that caffeine improved psychomotor vigilance, which is important for performance. Caffeine decreased the number of lapses on a standardized test of performance [SMD = 0.75 (95% CI: 0.30 to 1.19), p = 0.001], and lessened the slowing of reaction time at the end of shifts [SMD = 0.52 (95% CI: 0.19 to 0.85); p = 0.002]. Finally, 2 studies reported that caffeine reduced sleep quality and sleep duration. CONCLUSIONS: Although the quality of evidence was judged to be low to moderate, when taken together, these studies demonstrate that caffeine can improve psychomotor performance and vigilance. However, caffeine negatively affects sleep quality and sleep duration. More systematic, randomized studies need to be conducted in EMS workers in order to address the critical outcomes of health and safety of EMS personnel and patients. The risk/benefit ratio of chronic caffeine use in shift workers is currently unknown.

Experimental scarcity increases the relative reinforcing value of food in food insecure adults.

People with fewer financial resources are at greater risk for obesity, but the mechanisms of this relationship are not fully understood. One factor that is related, both cross-sectionally and prospectively, to obesity is the relative reinforcing value of food. It is possible that the experience of scarcity increases this reinforcing value. To date, no studies have examined this potential relationship experimentally in humans. The purpose of the studies presented here was to test the hypothesis that experimental manipulations of perceived scarcity would impact the relative reinforcing value of food. A secondary hypothesis was that individuals who report experiencing food insecurity would be more sensitive to these experimental manipulations. In order to test these hypotheses, we investigated the effects of experimentally manipulated scarcity on the relative reinforcing value of food in a laboratory setting. Study 1 had a within-subjects design and included 25 adults. Scarcity was manipulated by placing time and resource limits on the relative reinforcing value task and examining responding for a high calorie snack food versus that of an alternative reinforcer. Study 1 showed a tendency for food insecure participants to respond more for all reinforcers across conditions and have a higher proportional response for food when resources were limited. Study 2 also made use of a within-subjects design with 30 adults and primed scarcity by creating financial gains and losses on the Iowa Gambling Task. We observed higher relative reinforcing values of food among food insecure participants in the control condition, which decreased in the financial gain condition. When taken together, these two studies suggest that individuals who report experiencing food insecurity respond to acute manipulations of scarcity by increasing their reinforcing value of snack food.

Behavioral sensitization of the reinforcing value of food: What food and drugs have in common.

Sensitization is a basic property of the nervous system whereby repeated exposure to a stimulus results in an increase in responding to that stimulus. This increase in responding contributes to difficulty with treatment of drug abuse, as stimuli associated with substance use become signals or triggers for drug craving and relapse. Our work over the past decade has applied the theoretical framework of incentive sensitization to overeating. We have shown, in several studies, that lean adults do not commonly demonstrate behavioral sensitization after repeated exposure to snack food, but a subset of obese adults reliably does. This review will discuss this change in behavioral response to repeated consumption of snack food in obese individuals and apply the theoretical framework of incentive sensitization to drugs of abuse to high fat/high sugar snack foods. We will also show data that suggest that behavioral sensitization to repeated administration of snack food is predictive of weight gain, which may enhance its utility as a diagnostic tool for identifying at-risk individuals for obesity. Finally, we will discuss the future directions of this line of research, including studying the phenomenon in children and adolescents and determining if similar principles can be used to increase motivation to eat healthier food. A combination of reductions in unhealthy food intake and increases and healthy food intake is necessary to reduce obesity rates and improve health.

Taste and food reinforcement in non-overweight youth.

Food reinforcement is related to increased energy intake, cross-sectionally related to obesity and prospectively related to weight gain in children, adolescents and adults. There is very limited research on how different characteristics of food are related to food reinforcement, and none on how foods from different taste categories (sweet, savory, salty) are related to food reinforcement. We tested differences in food reinforcement for favorite foods in these categories and used a reinforcing value questionnaire to assess how food reinforcement was related to energy intake in 198 non-overweight 8- to 12-year-old children. Results showed stronger food reinforcement for sweet foods in comparison to savory or salty foods. In multiple regression models, controlling for child sex, minority status and age, average reinforcing value was related to total energy and fat intake, and reinforcing value of savory foods was related to total energy and fat intake. Factor analysis showed one factor, the motivation to eat, rather than separate factors based on different taste categories. Liking ratings were unrelated to total energy intake. These results suggest that while there are differences in the reinforcing value of food by taste groups, there are no strong differences in the relationship between reinforcing value of food by taste groups and energy or macronutrient intake.

Short term aerobic exercise alters the reinforcing value of food in inactive adults.

Motivation to eat, or the reinforcing value of food, may be influenced by a number of factors, including physical activity. The purpose of these studies was to test the hypothesis that short-term moderate-vigorous intensity aerobic exercise would alter the reinforcing value of high (HED) and low (LED) energy density foods in inactive adults. The reinforcing value of LED and HED food was measured at baseline and again after two weeks of aerobic exercise. In Experiment 1, 41 participants were randomized to a no exercise condition or aerobic exercise for 3 days per week for two weeks. In Experiment 2, 76 participants were randomized to one of four aerobic exercise frequencies, 0, 1, 3, or 5 days per week for two weeks. In both experiments, exercise reduced the reinforcing value of HED food compared to baseline and to non-exercise controls. In Experiment 2, the 5 day group also showed a significant increase in the reinforcing value of LED food compared to baseline and other exercise frequencies. Liking of HED and LED foods and consumption of HED food were not affected by exercise treatment. Finally, in Experiment 2, the 5 day group reported consuming more energy outside of the laboratory than the other groups. Taken together, these data suggest, in inactive individuals, motivation to obtain HED and LED foods can be altered with a short-term moderate-vigorous intensity exercise intervention. Further research is needed to understand the cognitive and physiological processes involved in food choices paired with exercise.

Taste and Appetite at Altitude: A Comprehensive Review of Sensory and Hunger Modulation in High-Altitude Environments.

Introduction: Individuals living or working at high altitudes typically experience altered taste perceptions and reduced appetite. These changes can lead to nutritional deficiencies, affecting the energy balance and body composition. Methods: We conducted a nonsystematic review of PubMed to explore these phenomena and expound on their findings to offer additional insights. Results: Changes in taste and perception are common and typically lead to loss of mass. There are limited practical solutions to mitigate these challenges. Discussion: Gradual acclimatization and tailored nutritional strategies are required to enhance health and performance in high-altitude environments. This review provides critical insights into the intersection of altitude, nutrition, and health.

The relationship among disordered eating behavior, power of food scale and sensitization of the reinforcing value of food.

INTRODUCTION: Disordered eating behaviors are a current public health concern since their progression can lead to the development of a full criteria eating disorder. Sensitization to repeated intake of high energy density (HED) foods is associated with excess weight gain over time, but less is known about relationships with assessments of disordered eating. Thus, this study aims to understand how disordered eating behaviors refunlate to the influence of the food environment and sensitization. METHOD: 163 adolescents - 50 % female and 13.2 mean age - were followed for 24 months. Sensitization was assessed by comparing the relative reinforcing value (RRV) of HED food at baseline and after two weeks of daily intake; sensitization was defined as RRV of food after repeated intake. Study participants also completed the EDE-Q, and Power of Food Scale (PFS). We conducted multivariate general linear models to examine these associations. RESULTS: Sensitization status and PFS scores at baseline were positively associated with EDE-Q subscale scores cross-sectionally, but not longitudinally, at baseline and 24 months. We found that sensitization to HED food and higher susceptibility to food cues relates to increased disordered eating behaviors and both at baseline and at 24-months. DISCUSSION: These findings suggest that sensitization to repeated HED food intake and the food environment might be a risk factor for later engagement in disordered eating behaviors. Future studies should address the temporal relationships among these factors and the role that social norms around body weight and weight stigma may play in the development of these behaviors.

The Influence of Relative Reinforcing Value of Food, Sensitization, Energy Intake and Diet Quality on zBMI Change over Two Years in Adolescents: A Longitudinal Cohort Study.

The relative reinforcing value (RRV) of food and sensitization are associated with zBMI and zBMI change over time, but the mechanisms underlying these relationships is unknown. The purpose of this study was to test the hypothesis that greater RRV and sensitization to HED food is associated with lower diet quality and greater energy intake at baseline and again at 24 months and that these relationships result in greater zBMI gain. The RRV of HED and LED food and dietary intake were measured at baseline and again after 24 months in a cohort of 202 boys and girls of 12-14 years old. The baseline RRV of HED food was associated with lower diet quality and lower energy intake at 24 months. zBMI gain was positively associated with the baseline energy intake but not baseline RRV of HED food or diet quality. However, diet quality moderated the relationship between baseline energy intake and zBMI change, with no difference in zBMI change as a function of energy intake when diet quality was high but significant and opposite relationships with energy intake when diet quality was low. This study suggests that high diet quality can reduce the negative impact of greater energy intake on zBMI change in adolescents.

Delay Discounting and the Income-Food Insecurity-Obesity Paradox in Mothers.

Food insecurity, defined as unpredictable access to food that may not meet a person's nutritional needs, is paradoxically associated with higher BMI (kg/m2) and obesity. Research has shown delay discounting, a behavioral economic measure of the preference for immediate rather than delayed rewards, is related to higher BMI, and moderates the relationship between income and food insecurity. Based on this research, we used regression models to test whether delay discounting, consideration of future consequences, and perceived stress were atemporal mediators of the food insecurity-BMI relation in 313 mothers, controlling for demographic variables. A secondary aim was to replicate the finding that delay discounting moderates the relationship between low income and high food insecurity. Results showed that low income was associated with higher food insecurity, and higher food insecurity was associated with higher BMI. Delay discounting was the only variable that was indirectly related to both paths of the food-insecurity-BMI relation. Delay discounting accounted for 22.2% of the variance in the low-income-food insecurity-obesity relation, and the total model accounted for 38.0% of the variance. The relation between low income and food insecurity was moderated by delay discounting. These data suggest that delay discounting is a potential mediator of the relationship between food insecurity and high BMI, which suggests reducing discounting in the future could be a novel target to reduce food insecurity and help people with food insecurity to reduce their excess body weight. Trial Registration. This trial is registered with NCT02873715.

Restriction and Pressure to Eat Are Associated Cross-Sectionally, But Not Longitudinally, With BMI z-Score in a Longitudinal Cohort Study of Adolescents.

Background: Parents can influence child weight through their use of food parenting practices, although data are limited in adolescents. The purpose of this study was to examine the cross-sectional and longitudinal relationships between BMI z-Score (zBMI) and restriction and pressure to eat in adolescents. Methods: Adolescents (12-14 years of age at baseline; N = 236) had their height/weight measured at baseline and 24 months and their parent completed the Child Feeding Questionnaire. Linear regressions examined relationships between food parenting practices and zBMI. Results: Cross-sectionally, restriction was positively associated with zBMI at both baseline (ß = 0.28, p < 0.001) and 24 months (ß = 0.141, p = 0.039). In contrast, pressure to eat was negatively associated with zBMI at both baseline (ß = -0.30, p < 0.001) and 24 months (ß = -0.31, p < 0.001). Neither restriction (ß = -0.028, p = 0.446) nor pressure to eat (ß = -0.027, p = 0.493) at baseline predicted 2-year changes in zBMI. zBMI at baseline did not predict 2-year changes in either restriction (ß = -0.003, p = 0.965) or pressure to eat (ß = -0.056, p = 0.611). Conclusion: Findings highlight that adolescents perceive moderate levels of restriction and pressure to eat, with levels differing by weight status. These findings suggest that the bidirectional relationships between child weight status and food parenting practices are likely established before adolescence, but persist throughout adolescence. Further longitudinal studies should examine the impact of restriction and pressure to eat early in childhood on weight trajectories into adolescence and adulthood. Clinicaltrials.gov: NCT04027608.