Do emotions predict eating? The role of previous experiences in emotional eating in the lab and in daily life.

Emotional eating is defined as an increase in eating following negative emotion. Self-reported emotional eating has been associated with physical health concerns. However, experimental and daily diary studies indicate that induced or naturally experienced negative emotions do not reliably lead to increased eating behavior in people without eating disorders, not even among self-professed emotional eaters. Emotional eating may depend on associations people have made between specific emotions and eating. We describe a set of studies with the overarching goal of determining whether accounting for the variation in people's associations between eating and different discrete emotions is the key to observing emotional eating. In both Study 1 (N = 118) and 2 (N = 111), we asked people to report on their tendency to eat following sadness and anxiety and determined how much they ate when induced to feel sad or anxious in the lab (Study 1) or experiencing these emotions in daily life (Study 2). We found no support for our hypotheses in either study; self-professed sad- or anxious-eaters did not eat more when induced to experience these emotions in the lab, or when experiencing these emotions in daily life. Thus, accounting for the variation in people's associations between eating and two discrete emotions, sadness and anxiety, is not the key to observing sad or anxious eating behavior in the lab or in daily life. Preregistration, materials, data, and code: https://osf.io/kcqej/ (Study 1) and https://osf.io/3euvg/ (Study 2).

Caffeine alters emotion and emotional responses in low habitual caffeine consumers.

Caffeine reliably increases emotional arousal, but it is unclear whether and how it influences other dimensions of emotion such as emotional valence. These experiments documented whether caffeine influences emotion and emotion regulation choice and success. Low to abstinent caffeine consumers (maximum 100 mg/day) completed measures of state anxiety, positive and negative emotion, and salivary cortisol before, 45 min after, and 75 min after consuming 400 mg caffeine or placebo. Participants also completed an emotion regulation choice task, in which they chose to employ cognitive reappraisal or distraction in response to high and low intensity negative pictures (Experiment 1), or a cognitive reappraisal task, in which they employed cognitive reappraisal or no emotion regulation strategy in response to negative and neutral pictures (Experiment 2). State anxiety, negative emotion, and salivary cortisol were heightened both 45 and 75 min after caffeine intake relative to placebo. In Experiment 1, caffeine did not influence the frequency with which participants chose reappraisal or distraction, but reduced negativity of the picture ratings. In Experiment 2, caffeine did not influence cognitive reappraisal success. Thus, caffeine mitigated emotional responses to negative situations, but not how participants chose to regulate such responses or the success with which they did so.

Habitual exercise is associated with cognitive control and cognitive reappraisal success.

Habitual exercise is associated with enhanced domain-general cognitive control, such as inhibitory control, selective attention, and working memory, all of which rely on the frontal cortex. However, whether regular exercise is associated with more specific aspects of cognitive control, such as the cognitive control of emotion, remains relatively unexplored. The present study employed a correlational design to determine whether level of habitual exercise was related to performance on the Stroop test measuring selective attention and response inhibition, the cognitive reappraisal task measuring cognitive reappraisal success, and associated changes in prefrontal cortex (PFC) oxygenation using functional near-infrared spectroscopy. 74 individuals (24 men, 50 women, age 18-32 years) participated. Higher habitual physical activity was associated with lower Stroop interference (indicating greater inhibitory control) and enhanced cognitive reappraisal success. Higher habitual exercise was also associated with lower oxygenated hemoglobin (O2Hb) in the PFC in response to emotional information. However, NIRS data indicated that exercise was not associated with cognitive control-associated O2Hb in the PFC. Behaviorally, the findings support and extend the previous findings that habitual exercise relates to more successful cognitive control of neutral information and cognitive reappraisal of emotional information. Future research should explore whether habitual exercise exerts causal benefits to cognitive control and PFC oxygenation, as well as isolate specific cognitive control processes sensitive to change through habitual exercise.

Caffeine and theanine exert opposite effects on attention under emotional arousal.

Tea is perceived as more relaxing than coffee, even though both contain caffeine. L-theanine in tea may account for the difference. Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitigates physiological and felt stress responses. We evaluated whether caffeine and theanine influenced cognition under emotional arousal. Using a double-blind, repeated-measures design, 36 participants received 4 treatments (200 mg caffeine + 0 mg theanine, 0 mg caffeine + 200 mg theanine, 200 mg caffeine + 200 mg theanine, 0 mg caffeine + 0 mg theanine) on separate days. Emotional arousal was induced by highly arousing negative film clips and pictures. Mood, salivary cortisol, and visual attention were evaluated. Caffeine accentuated global processing of visual attention on the hierarchical shape task (p < 0.05), theanine accentuated local processing (p < 0.05), and the combination did not differ from placebo. Caffeine reduced flanker conflict difference scores on the Attention Network Test (p < 0.05), theanine increased difference scores (p < 0.05), and the combination did not differ from placebo. Thus, under emotional arousal, caffeine and theanine exert opposite effects on certain attentional processes, but when consumed together, they counteract the effects of each other.

The impact of caffeine use across the lifespan on cognitive performance in elderly women.

Habitual caffeine consumption has often been associated with decreasing age-related cognitive decline. However, whether habitual caffeine use preferentially spares different cognitive processes is unclear. Furthermore, whether basing habitual caffeine consumption patterns on current consumption or on a lifetime measure better represents an individual's use remains unclear. In the present study, we collected information from women, aged 56-83, about their current caffeine consumption patterns and history of use, including age they began consuming caffeine. Regression models assessed the relationship between caffeine consumption and performance on batteries designed to probe speed of processing, inhibition, memory, and executive function. While we found no direct associations between caffeine exposure and cognitive performance, we found that caffeine consumption and participant BMI interacted for inhibitory function and speed of processing performance. We discuss possible protective effects of long term caffeine use as well as the possibility of dose dependent effects.

Exercise promotes positive impression formation towards both men and women.

Exercise is endorsed for its physiological and psychological benefits, and has been proposed to have positive effects on impression formation. To test this proposal, 62 female and 44 male college students read one of three brief descriptions of either a fictitious male or female "target" student. The descriptions varied only in exercise level: no exercise; moderate exercise and intensive exercise. Participants then rated the fictitious student on 38 personality traits. Ratings of characteristics that are associated with exercise (e.g. athletic; energetic) increased, while ratings associated with the lack of exercise (e.g. lazy; weak) decreased as a function of the reported level of exercise. Exercise level also positively influenced ratings of characteristics not related to exercise. These data show that even minimal information about exercise is an important component of first impressions in both men and women.

Foods that are perceived as healthy or unhealthy differentially alter young women's state body image.

Body image can be influenced by day-to-day events, including food intake. The present study investigated the effects of foods typically perceived as "healthy" or "unhealthy" on state body image and mood. College-aged women were told the experiment was designed to assess the effects of food on cognition. Using a between-subjects design, participants consumed isocaloric amounts of foods perceived to be healthy (banana) or unhealthy (donut) or ate nothing. Next, participants completed three cognitive tasks. Prior to eating and following the cognitive tests, participants completed the BISS, POMS, the Figure Rating Scale, and the Restraint Scale. Body satisfaction decreased following intake of a donut, but was not altered in the other conditions. Depression scores significantly decreased after intake of either a donut or banana, but did not decrease in the no-food condition. Tension scores decreased significantly after consumption of a banana and in the no-food condition, but did not decrease following consumption of a donut. These results indicate that intake of a food that is perceived as unhealthy negatively affects state body image.

Sucrose-induced obesity impairs novel object recognition learning in young rats.

In addition to its metabolic consequences, obesity may lead to impairments in learning and memory. To test this possibility, male Long-Evans rats were fed ground chow, or chow and either a 32% sucrose solution or hydrogenated vegetable fat (Crisco) for eight weeks. Cognitive behavior was then assessed using a novel object recognition task. To determine if there was a relationship between cognitive behavior and glucose metabolism, performance on the novel object recognition task was correlated with fasting blood glucose levels and responses on an oral glucose tolerance test. Rats fed sucrose or fat consumed more calories, gained more weight, and had larger epididymal fat pads than rats fed only chow. Additionally, fasting blood glucose levels, and the area under the glucose curve following an oral glucose tolerance test were greater in rats consuming a supplemental source of fat or sucrose than in those eating only chow. During training when rats were presented with two identical objects in an open field, time spent exploring the objects did not differ as a function of dietary conditions. However, when rats were tested 1 h later with one familiar and one novel object, rats given sucrose spent significantly less time exploring the novel object than rats eating only chow. The percent of time spent exploring the novel object was negatively correlated with fasting blood glucose levels, final body weights, and epididymal fat pad weights. It is hypothesized that the impairment in object recognition in rats eating sucrose is due, at least in part, to diet-induced alterations in glucose metabolism.

Low-carbohydrate weight-loss diets. Effects on cognition and mood.

To examine how a low-carbohydrate diet affects cognitive performance, women participated in one of two weight-loss diet regimens. Participants self-selected a low-carbohydrate (n=9) or a reduced-calorie balanced diet similar to that recommended by the American Dietetic Association (ADA diet) (n=10). Seventy-two hours before beginning their diets and then 48 h, 1, 2, and 3 weeks after starting, participants completed a battery of cognitive tasks assessing visuospatial memory, vigilance attention, memory span, a food-related paired-associates a food Stroop, and the Profile of Moods Scale (POMS) to assess subjective mood. Results showed that during complete withdrawal of dietary carbohydrate, low-carbohydrate dieters performed worse on memory-based tasks than ADA dieters. These impairments were ameliorated after reintroduction of carbohydrates. Low-carbohydrate dieters reported less confusion (POMS) and responded faster during an attention vigilance task (CPT) than ADA dieters. Hunger ratings did not differ between the two diet conditions. The present data show memory impairments during low-carbohydrate diets at a point when available glycogen stores would be at their lowest. A commonly held explanation based on preoccupation with food would not account for these findings. The results also suggest better vigilance attention and reduced self-reported confusion while on the low-carbohydrate diet, although not tied to a specific time point during the diet. Taken together the results suggest that weight-loss diet regimens differentially impact cognitive behavior.

Relationships between use of dietary supplements, caffeine and sensation seeking among college students.

Objective: Caffeine and dietary supplement (DS) use by college students is not well-documented. Given reported associations between energy drink consumption and sensation seeking, we used the Sensation Seeking Scale Form V (SSS-V) to assess relationships between sensation-seeking, caffeine, and DS use. Participants: Data from 1,248 college students from five US institutions were collected from 2009 to 2011. Methods: Linear regression was used to examine relationships between scores on the SSS-V and caffeine and DS use, demographic, and lifestyle characteristics. Results: Male sex, nonHispanic race-ethnicity, higher family income, tobacco use, consuming caffeinated beverages, more than 400 mg caffeine per day, and energy drinks with alcohol at least 50% of the time, were significantly associated with higher total SSS-V scores (P < 0.001). Those using protein DSs had higher total, disinhibition, and boredom susceptibility SSS-V scores (Ps < 0.001). Conclusions: Results demonstrate a positive correlation between sensation-seeking attitudes and habitual caffeine, energy drink, and DS consumption.

Diet-induced obesity and spatial cognition in young male rats.

Recent work suggests that obesity may adversely affect cognitive behavior. To examine this suggestion, the effects of feeding a standard chow diet, and either supplemental sugar or fat on the development of obesity and performance on a test of spatial learning, the Morris Water Maze (MWM), were assessed in young male Long-Evans rats. Rats given access to a sucrose solution or dietary fat in addition to the chow diet consumed approximately 10% more calories per day, gained more weight, and had larger epididymal fat pads than rats fed the chow diet alone. Moreover, rats fed the supplemental sucrose took significantly more time to find a hidden platform in the MWM than rats fed the chow diet alone or chow and supplemental fat. Additionally, when tested 10 days after the initial training trials, rats given sucrose displayed deficits in long-term spatial memory. After 6 weeks on the diets, fasting blood glucose and serum triglyceride concentrations were significantly higher in sucrose-fed rats than in rats eating only the standard diet. These results indicate that diet-induced obesity resulting from excess sucrose intake, but not fat intake, in young animals impairs spatial learning and memory. It is hypothesized that these deficits arise from metabolic insults that leave the brain vulnerable to alterations in insulin sensitivity and glucose metabolism.

Breakfast food health and acute exercise: Effects on state body image.

Food intake and exercise have been shown to alter body satisfaction in a state-dependent manner. One-time consumption of food perceived as unhealthy can be detrimental to body satisfaction, whereas an acute bout of moderate-intensity aerobic exercise can be beneficial. The current study examined the effect of exercise on state body image and appearance-related self-esteem following consumption of isocaloric foods perceived as healthy or unhealthy in 36 female college students (18-30 years old) in the Northeastern United States. Using a randomized-controlled design, participants attended six study sessions with breakfast conditions (healthy, unhealthy, no food) and activity (exercise, quiet rest) as within-participants factors. Body image questionnaires were completed prior to breakfast condition, between breakfast and activity conditions, and following activity condition. Results showed that consumption of an unhealthy breakfast decreased appearance self-esteem and increased body size perception, whereas consumption of a healthy breakfast did not influence appearance self-esteem but increased body size perception. Exercise did not influence state body image attitudes or perceptions following meal consumption. Study findings suggest that morning meal type, but not aerobic exercise, influence body satisfaction in college-aged females.

Sugar intake and expectation effects on cognition and mood.

Glucose intake has been found to improve some aspects of cognitive performance; however, results are often inconsistent. This inconsistency may be related to expectations surrounding glucose, which can have strong effects on performance outcomes. The present study evaluated the independent and interactive effects of acute sugar intake, in the form of high-fructose corn syrup (HFCS), and sugar expectancies on cognitive performance and mood. One hundred five healthy young adults were randomized according to sugar intake and expectation: consumed-sugar/told-sugar, consumed-sugar/told-no-sugar, consumed-no-sugar/told-sugar, and consumed-no-sugar/told-no-sugar. Thirty minutes after sugar or no-sugar intake, participants completed the Profile of Mood States and a battery of cognitive tests, including immediate and delayed recall, the Stroop test, n-back task, and continuous performance task. Tension increased following the expectation of consuming sugar, regardless of sugar consumption (p < .05). On the continuous performance task, accuracy and sensitivity were higher (ps < .05) and false alarm rate was lower (p < .05) following sugar than no sugar intake. No effects of sugar intake or expectation were found for any other mood or cognitive measure (ps > .05). The findings suggest that sugar intake in the form of HFCS may benefit certain cognitive processes, such as those that require sustained attention, but that the expectation of sugar intake is not sufficient to produce such benefits. (PsycINFO Database Record

Endurance Exercise Enhances Emotional Valence and Emotion Regulation.

Acute exercise consistently benefits both emotion and cognition, particularly cognitive control. We evaluated acute endurance exercise influences on emotion, domain-general cognitive control and the cognitive control of emotion, specifically cognitive reappraisal. Thirty-six endurance runners, defined as running at least 30 miles per week with one weekly run of at least 9 miles (21 female, age 18-30 years) participated. In a repeated measures design, participants walked at 57% age-adjusted maximum heart rate (HRmax; range 51%-63%) and ran at 70% HRmax (range 64%-76%) for 90 min on two separate days. Participants completed measures of emotional state and the Stroop test of domain-general cognitive control before, every 30 min during and 30 min after exercise. Participants also completed a cognitive reappraisal task (CRT) after exercise. Functional near-infrared spectroscopy (fNIRS) tracked changes in oxygenated and deoxygenated hemoglobin (O2Hb and dHb) levels in the prefrontal cortex (PFC). Results suggest that even at relatively moderate intensities, endurance athletes benefit emotionally from running both during and after exercise and task-related PFC oxygenation reductions do not appear to hinder prefrontal-dependent cognitive control.

Diet selection improves morphine's antinociceptive actions in rats with streptozotocin-induced diabetes.

Following the administration of the diabetogenic drug streptozotocin, rats selecting their diet from separate sources of macronutrients (e.g., proteins, fats, and carbohydrates) demonstrated less severe symptoms of diabetes than did rats fed ground Purina chow or a composite diet containing the same nutrient sources as found in the self-selection diet but in the proportions found in chow. After the induction of diabetes, rats selecting their own diet ate and drank less, weighed more, and had more adipose tissue and lower blood glucose levels than did rats consuming chow or the composite diet. In addition, rats choosing their diet were more sensitive to morphine's pain-relieving properties than were rats in the other 2 dietary groups. Rats given the self-selecting diet consumed more protein and fat and less carbohydrate than did those eating a single diet. Data suggest that rats must select their diet preceding and following the induction of diabetes for amelioration of diabetic symptoms to occur. These results indicate that diet can contribute to the severity of diabetes and could be used as an adjunct to standard treatment of the disease.

Effect of an afternoon confectionery snack on cognitive processes critical to learning.

Two experiments examined how an afternoon confectionery snack affects a variety of cognitive processes critical to learning. For Experiment 1, thirty-eight male undergraduates completed a dual learning task where the primary task involved learning either a map or stories and the secondary task required monitoring a radio broadcast for a specific word category. Results showed that for map learning, participants who consumed the confectionery snack performed better on the primary task. They correctly placed more country names and left fewer blanks on a map during long-term recall. However, on the secondary attention task, participants who consumed the confectionery snack had a lower hit rate. The confectionary snack did not affect story memory performance. In Experiment 2, 38 boys, aged 9-11 years, participated in a similar, age appropriate task. Results showed that boys who had consumed the confectionery snack correctly placed more names and left fewer blanks on a map in both short-term and long-term recall. In contrast with Experiment 1, performance on the secondary task was better after confectionary consumption. However, when tested on a separate vigilance attention task, children who consumed the placebo performed better. Overall results indicate that a confectionery snack, ingested in the afternoon, generally improves spatial memory, but has a mixed effect on attention performance.

Impaired reversal learning in an animal model of anorexia nervosa.

BACKGROUND: Clinical investigations indicate that anorexia nervosa (AN) is associated with impaired cognitive flexibility. Activity-based anorexia (ABA), a rodent behavioral model of AN, is characterized by compulsive wheel running associated with voluntary food restriction and progressive weight loss. The goal of this study was to test whether ABA is associated with impaired cognitive flexibility. METHODS: Female Sprague-Dawley rats were trained to perform the attentional set-shifting test (ASST) to assess cognitive flexibility, including capacity for set-shifting and reversal learning. Rats were assigned to ABA or weight-loss paired control (WPC) conditions. Following baseline testing, the ABA group had access to food for 1h/d and access to running wheels 23h/d until 20% weight loss was voluntarily achieved. For the WPC group, running wheels were locked and access to food was restricted to reduce body weight at the same rate as the ABA group. ASST performance was assessed after weight loss, and again following weight recovery. RESULTS: Compared to baseline, the ABA group (but not the WPC group) showed a significant decrement in reversal learning at low weight, with return to baseline performance following weight restoration. The other components of ASST were not affected. CONCLUSIONS: Impaired reversal learning, indicative of increased perseverative responding, in the ABA model reveals its potential to recapitulate selective components of cortical dysfunction in AN. This finding supports the utility of the ABA model for investigations of the neural mechanisms underlying such deficits. Reversal learning relies on neural circuits involving the orbitofrontal cortex and thus the results implicate orbitofrontal abnormalities in AN-like state.

Chronic running wheel activity attenuates the antinociceptive actions of morphine and morphine-6-glucouronide administration into the periaqueductal gray in rats.

Chronic exercise in a running wheel increases baseline pain sensitivity while attenuating the antinociceptive effects of peripherally administered opiate agonists in laboratory rodents. To determine if these effects are due to exercise-induced changes in the central nervous system (CNS) or an artifact of exercise-induced alterations in peripheral physiology, the present study evaluated the antinociceptive actions of centrally administered opiate agonists in active and inactive female rats. Rats were implanted with cannula into the right periaqueductal gray (PAG) area of the midbrain. After the completion of the surgery, the animals were allowed ad libitum access to running wheels or housed in standard cages for three weeks. Pain sensitivity was measured on the tail flick test before and immediately following microinjections of either morphine (0, 2.5, 5.0, 10.0, 20.0 microg/rat) or the more potent morphine metabolite, morphine-6-glucuronide (M6G) (0, 0.03, 0.1, 0.3, 1.0 microg/rat). Baseline tail flick latencies were significantly shorter in active than in inactive rats. Additionally, active animals were less sensitive to the antinociceptive effects of morphine and M6G than inactive rats. These findings provide evidence for the involvement of the CNS in exercise-mediated alterations in pain sensitivity and opiate drug actions.

Persistent exercise attenuates nicotine- but not clonidine-induced antinociception in female rats.

Exercise decreases the antinociceptive effects of opiate drugs. It has been hypothesized that the exercise-induced attenuation of opiate drug action is the result of the development of cross-tolerance between endogenous opioids released during exercise and exogenous opiates. The present study was designed to evaluate the role of exercise on non-opiate antinociception. Female Long-Evans rats were allowed ad lib access to running wheels. After 3 weeks, antinociceptive responses of animals were measured using the tail flick test following the administration of clonidine or nicotine. Nicotine and clonidine both produced dose-dependent increases in antinociceptive responses. Active animals were significantly less sensitive to nicotine-induced antinociception than inactive animals. There was no difference between the two groups in clonidine-induced antinociception. The results of these experiments suggest that exercise does not attenuate non-opioid, clonidine-induced antinociception. However, exercise does attenuate nicotine-induced antinociception. Therefore, the effect of persistent exercise on analgesic drugs is not specific to opiates.

Effect of breakfast composition on cognitive processes in elementary school children.

The relationship between breakfast composition and cognitive performance was examined in elementary school children. Two experiments compared the effects of two common U.S. breakfast foods and no breakfast on children's cognition. Using a within-participant design, once a week for 3 weeks, children consumed one of two breakfasts or no breakfast and then completed a battery of cognitive tests. The two breakfasts were instant oatmeal and ready-to-eat cereal, which were similar in energy, but differed in macronutrient composition, processing characteristics, effects on digestion and metabolism, and glycemic score. Results with 9 to 11 year-olds replicated previous findings showing that breakfast intake enhances cognitive performance, particularly on tasks requiring processing of a complex visual display. The results extend previous findings by showing differential effects of breakfast type. Boys and girls showed enhanced spatial memory and girls showed improved short-term memory after consuming oatmeal. Results with 6 to 8 year-olds also showed effects of breakfast type. Younger children had better spatial memory and better auditory attention and girls exhibited better short-term memory after consuming oatmeal. Due to compositional differences in protein and fiber content, glycemic scores, and rate of digestion, oatmeal may provide a slower and more sustained energy source and consequently result in cognitive enhancement compared to low-fiber high glycemic ready-to-eat cereal. These results have important practical implications, suggesting the importance of what children consume for breakfast before school.