Intermittent sucrose solution intake and its schedule of access modulate energy intake and weight gain in response to chronic variable stress in mice.

There is a strong relationship between stress and the intake of calorically-dense palatable food. Additionally, intake of sodas is an important contributory factor to obesity, and is often associated with palatable food consumption. We studied the effects of 2-h intermittent access to sucrose-sweetened water (SSW, 12.3%, soda-like) and its schedule of administration on the response to chronic variable stress in mice fed a high-fat, high-sugar diet. C57BL/6 mice (n = 64) had access to water or to both water and 2-h SSW during 5 weeks, in addition to their diet. After the first two weeks, half of the animals from each group were stressed daily using a chronic variable stress (CVS) paradigm, while the other half were kept undisturbed. During the CVS exposure period, 2-h SSW access was either scheduled randomly, right before the stressors or right after the stressors. The effects of SSW and its schedule of administration on dietary intake, stress hormones and adiposity were analyzed. Results showed a larger consumption of SSW and higher bodyweight gain in mice receiving SSW after the stressor. In addition, SSW consumption was shown to affect appetite regulation by reducing CCK sensitivity. The present study suggests that SSW leads to overconsumption and weight gain only if provided after exposure to stress. These findings may implicate a relation between exposure to stress, binge-drinking behaviors of sugar sweetened beverages that ensues, and weight gain in humans consuming a western diet.

Movie violence acutely affects food choices in young adults.

BACKGROUND: Extensive research has been conducted to investigate the effects of media violence on attitudes, behaviors, and cardiovascular health; however, only few studies have examined its effect on appetite, eating behavior and food preferences. Little attention has been given to understand how movie genre manipulates the physiology and the eating behavior of individuals. The present study aimed at investigating the acute effect of violence content in movies on appetite perception, heart rate and blood pressure, along with food preferences and intake in young individuals. METHODS: Participants (n = 84) were randomly assigned to either watch a violent movie or a non-violent narrative movie. Measurements including anthropometry, heart rate, blood pressure and grip strength were taken and appetite as well as stress perception were assessed. Subjects were then provided with an individual snack tray containing various items to be consumed ad libitum. RESULTS: Post intervention, the experimental group (EG) had a higher consumption of fatty (t (82) = 2.28, p = 0.025, d = 1.52) and salty (t (82) = 2.61, p = 0.01, d = 0.71) food items compared to the control group (CG). Out of the 42 participants in the EG 62% consumed >2 fatty items and 71.4% consumed >2 salty food items. No significant difference in the consumption of sugary items was observed between the two groups. CONCLUSION: Movie violence affects eating behavior and may promote weight gain.

Predictors of Disordered Eating in Young Males.

Recent findings suggest that disordered eating (DE) symptomatology may be underestimated in the male population. The present study examined depressive symptomatology as a potential mediator of the relationships between body image dissatisfaction, strategies to change body weight and muscles, media pressure, and DE (emotional, restrained and emotional eating) in 260 male undergraduates who completed a self-reported questionnaire. Path analyses indicated that media influence and strategies to decrease body weight had direct positive effects on depressive symptomatology, which in turn predicted emotional eating. Media influence had a direct positive effect on emotional eating, whereas strategies to decrease body weight did not exhibit a direct effect on emotional eating. Therefore, the latter pathway was removed from the model. The link between media pressure, strategies to decrease body weight and emotional eating was partially mediated by depressive symptomatology. The present findings can inform the development and implementation of prevention and education programs for DE in schools and universities.

Environmental enrichment and cafeteria diet attenuate the response to chronic variable stress in rats.

Exposure to an enriched environment (EE) or the intake of a highly palatable diet may reduce the response to chronic stress in rodents. To further explore the relationships between EE, dietary intake and stress, male Sprague-Dawley rats were fed one of two diets for 5 weeks: high carbohydrate (HC) or "cafeteria" (CAF) (Standard HC plus a choice of highly palatable cafeteria foods: chocolate, biscuits, and peanut butter). In addition, they were either housed in empty cages or cages with EE. After the first two weeks, half of the animals from each group were stressed daily using a chronic variable stress (CVS) paradigm, while the other half were kept undisturbed. Rats were sacrificed at the end of the 5-week period. The effects of stress, enrichment and dietary intake on animal adiposity, serum lipids, and stress hormones were analyzed. Results showed an increase in intra-abdominal fat associated with the CAF diet and an increase in body weight gain associated with both the CAF diet and EE. Furthermore, the increase in ACTH associated with CVS was attenuated in the presence of EE and the CAF diet independently while the stress-induced increase in corticosterone was reduced by the combination of EE and CAF feeding. The present study provides evidence that the availability of a positive environment combined to a highly palatable diet increases resilience to the effects of CVS in rats. These results highlight the important place of palatable food and supportive environments in reducing central stress responses.

Effect of movie violence on mood, stress, appetite perception and food preferences in a random population.

Very little is known about media violence and its effect on appetite and eating behavior. The present study aims at investigating the immediate acute effect of violence in movies on mood, stress, appetite perception and food preferences in a real-life setting. A total of 447 subjects (F = 202; M = 239) completed a validated visual analog scale to record their subjective feelings of hunger, satiety and desire to eat immediately at their way out of any of the three types of movies (horror, romance/comedy and drama/action). There was a significant difference between the three movie categories for the tensed feeling (P = 0.003), anxiety (P = 0.021), the sleepy feeling (P = 0.000) and a preference to eat something sweet (P = 0.019). Horror/violence movie types affected the subject by making him feel more stressed and anxious; however, romance made him feel sleepier and less tensed. Movie types did not seem to affect hunger or appetite directly, but rather triggered some food preferences.

The influence of sociocultural factors on the eating attitudes of Lebanese and Cypriot students: a cross-cultural study.

BACKGROUND: The present comparative cross-cultural study aimed to explore the relationship between eating behaviour and sociocultural influences with respect to appearance and body image in female university students from two cultural contexts, namely Cyprus and Lebanon. METHODS: The Dutch Eating Behavior questionnaire (DEBQ) and the Perceived Sociocultural Influences on Body Image and Body Change Questionnaire were used to assess sociocultural influences and body image, respectively, in 200 students from each country. RESULTS: The results indicated that the Lebanese students were more likely to engage in emotional and external eating and their body image was impacted to a larger extent by sociocultural agents, including media influences, compared to the Cypriot students. Also, a positive relationship was found between emotional and external eating in both cultures. Finally, sociocultural influences correlated positively with external eating only in the Cypriot sample. CONCLUSIONS: Culture-specific factors, such as the societal values and norms, as well as the Westernisation history of each country, are discussed as underpinnings for the differences found. These findings are significant for understanding the rise of eating pathology in these two cultures and provide evidence for a need to consider cultural environment when designing public health policies addressing the negative aspects of nutrition transition.

A cafeteria diet modifies the response to chronic variable stress in rats.

Stress is known to lead to metabolic and behavioral changes. To study the possible relationships between stress and dietary intake, male Sprague-Dawley rats were fed one of three diets for 6 weeks: high carbohydrate (HC), high fat (HF), or "Cafeteria" (CAF) (Standard HC plus a choice of highly palatable cafeteria foods: chocolate, biscuits, and peanut butter). After the first 3 weeks, half of the animals from each group (experimental groups) were stressed daily using a chronic variable stress (CVS) paradigm, while the other half of the animals (control groups) were kept undisturbed. Rats were sacrificed at the end of the 6-week period. The effects of stress and dietary intake on animal adiposity, serum lipids, and corticosterone were analyzed. Results showed that both chronic stress and CAF diet resulted in elevated total cholesterol, increased low-density lipoprotein (LDL), and lower high-density lipoprotein (HDL). In addition, increases in body weight, food intake, and intra-abdominal fat were observed in the CAF group compared with the other dietary groups. In addition, there was a significant interaction between stress and diet on serum corticosterone levels, which manifest as an increase in corticosterone levels in stressed rats relative to non-stressed controls in the HC and HF groups but not in the CAF group. These results show that a highly palatable diet, offering a choice of food items, is associated with a reduction in the response to CVS and could validate a stressor-induced preference for comfort food that in turn could increase body weight.

Peripherally injected cholecystokinin-induced neuronal activation is modified by dietary composition in mice.

The aim of this study was to investigate the effect of long-term nutrient intake on the central response to the anorexigenic gut hormone CCK. C57BL/6 mice were fed one of three diets for 6 weeks: standard high carbohydrate (HC), high fat (HF), or high protein (HP). Assessment of brain response to cholecystokinin (CCK) by manganese-enhanced MRI (MEMRI) showed a reduction in neuronal activity both in an appetite-related area (ventromedial nucleus of the hypothalamus) and areas associated with reward (nucleus accumbens and striatum) regardless of diet. When comparing diet effects, while the HF diet did not induce any change in activity, reductions in MEMRI-associated signal were found in the paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) when comparing the HP to the HC diet. In addition, a significant interaction was found between CCK administration and the HF diet, shown by an increased activation in the PVN, which suggests a decrease the inhibiting action of CCK. Our results put forward that the long-term intake of an HP diet leads to a reduction in basal hypothalamic activation while a high-fat diet leads to desensitization to CCK-induced effects in the hypothalamus.

Dietary protein level alters gentamicin-induced nephrotoxicity in rats.

Aminoglycosides (AG) such as gentamicin are antimicrobial drugs widely used in the hospital setting due to their efficacy in the treatment of severe gram-negative bacterial infections. However, all AG have the potential to cause nephrotoxicity. Two studies have been conducted (1) to assess the protein level of a diet that would give the best renal outcome with gentamicin administration, and (2) to get a better idea about the rhythms of food ingestion associated with the different protein levels. Adult female Sprague-Dawley rats fully adapted to a standard chow diet, the standard chow with 20% or 55% added casein were chronically treated for 10 days with a nephrotoxic dose of gentamicin sulfate (40 mg/kg/day, i.p.) or a saline solution. Food ingestion patterns of rats were recorded every hour using a Diet Scan system and gentamicin nephrotoxicity indices were measured. The second study used rats that were fed the same diets and given a sham injection. Corticosterone was assayed to quantify the stress of the animals. Results showed that chronic gentamicin treatment leads to a decrease in food intake and flattening of the rhythms of food ingestion. Also, chow feeding and the 20% casein diet were found to be more protective against gentamicin-induced nephrotoxicity than the 55% casein diet. Therefore, while a protein-rich diet can be protective against gentamicin-induced nephrotoxicity, the present study demonstrates that a diet too high in protein might rather be harmful to the kidneys.