Negative affect and neural response to palatable food intake in bulimia nervosa

Binge eating is often preceded by reports of negative affect, but the mechanism by which affect may lead to binge eating is unclear. This study evaluated the effect of negative affect on neural response to anticipation and receipt of palatable food in women with bulimia nervosa (BN) versus healthy controls. We also evaluated connectivity between the amygdala and reward-related brain regions. Females with and without BN (n=26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless solution. We measured negative affect just prior to the scan. Women with BN showed a positive correlation between negative affect and activity in the putamen, caudate, and pallidum during anticipated receipt of milkshake (versus tasteless solution). There were no significant relations between negative affect and receipt of milkshake. Connectivity analyses revealed a greater relation of amygdala activity to activation in the left putamen and insula during anticipated receipt of milkshake in the bulimia group relative to the control group. The opposite pattern was found for the taste of milkshake; the control group showed a greater relation of amygdala activity to activation in the left putamen and insula in response to milkshake receipt than the bulimia group. Results show that as negative affect increases, so does responsivity of reward regions to anticipated intake of palatable food, implying that negative affect may increase the reward value of food for individuals with bulimia nervosa or that negative affect has become a conditioned cue due to a history of binge eating in a negative mood.     

Modeling of palatable food intake. The influence of quality of social interaction

This study investigates the effects of the quality of social interaction on modeling of food intake among young women. A two (confederate's food intake: high versus low) by two (confederate's sociability: sociable versus unsociable) between-participant factorial design was employed. A total of 100 young women (18–27 years) participated. Findings indicated that young women generally ate more when exposed to a high-intake peer than women exposed to a low-intake peer. However, this modeling effect was only found in the unsociable context. This study underscores the influence of social atmosphere on modeling effects of palatable food intake and suggests that contextual uncertainty or ingratiation strategies may be important in explaining the magnitude of modeling effects.     

Modeling of palatable food intake in female young adults. Effects of perceived body size

Laboratory taste-test studies have shown that social modeling effects on food intake are powerful. The aim of the present study was to examine the degree to which people model food intake in a more naturalistic eating setting. After completing a cover task, female participants (N=102) spent a 15-min break with a female confederate who ate a large amount or a small amount of M&Ms or no M&Ms at all. Further, the confederate had a slim or (subtly manipulated) normal-weight appearance. Females who were exposed to a confederate who ate much consumed more than those who were confronted with a confederate who ate only a little or nothing at all. Although the manipulation of the confederate's appearance had no significant main effect on the amount of food that participants consumed, a significant interaction effect was found, such that the modeling effect of eating was present only in the normal-weight appearance condition. Our findings suggest that normal-weight young women are more inclined to imitate the food intake of a female confederate if they are more similar to the confederate.     

中国2010—2012年6~17岁儿童青少年睡眠状况

目的探索上海市高中生睡眠不足的现况及其与日常体力活动情况的关系。方法2015—2016年,在上海市各个区采用按比例系统随机抽样方法抽取28所高中学校,再采取简单随机整群抽样方法,在每个学校的每个年级随机抽取2个班级,采用《上海市青少年健康相关行为调查问卷(高中版)》对高中学生的睡眠时间和体力活动情况进行调查。结果共抽取有效样本6 401人(男生占45.6%,女生占54.4%)。62.8%的被调查高中生每日睡眠时间小于7 h, 94.8%的高中生小于8 h。单因素分析发现,女生较男生、高年级较低年级睡眠不足情况更严重;每日身体活动时间达60 min、每日中等强度活动达30 min、每天步行或骑车达30 min、每周体育课数、每周课外体育锻炼量均与睡眠时间正相关。多因素分析发现,性别、年级、每日步行或骑车时间、每周课外体育锻炼量对于高中生睡眠时间有促进作用。结论上海地区高中生睡眠时间严重不足。体力活动中步行、骑车及课外体育锻炼对睡眠时间起正性促进作用,在健康教育中应鼓励学生每日多步行或骑车、多参加课外体育活动以改善睡眠时间不足。     

Hunger and food intake following consumption of low-calorie foods

Although high-intensity sweeteners are widely used to decrease the energy density of foods, little is known about how this affects hunger and food intake. We have studied the effects of consumption of commercially available foods sweetened with either sucrose or aspartame on subjective appetite ratings and food intake. When normal-weight non-dieting males and females were given large portions of either a high- or low-calorie pudding or jello and instructed to eat as much as they liked, they ate similar weights of the different caloric versions of each food. Despite the resulting difference in caloric intake (up to 206 kcal), subjects showed only a non-significant trend towards caloric compensation when presented with a variety of foods 2 h later. Total caloric intake (preload plus test meal) did not differ between conditions. Ratings of hunger, desire to eat, the amount subjects wanted to eat, and the pleasantness of the taste of the eaten food were similarly decreased and fullness similarly increased by consumption of the different caloric versions of the foods. Awareness of the caloric content of the foods did not influence intake or appetite in that both informed and uniformed subjects responded similarly in the tests. Thus reduced calorie foods suppressed ratings of hunger for several hours after consumption, but were not associated with a significant reduction in total energy intake.     

Pre-exposure to high- versus low-caloric foods: effects on children's subsequent fruit intake

The effects of pre-exposure to high- versus low-caloric foods on fruit intake were investigated. A total of 56 children participated in this study, and were randomly assigned to an exposure condition: high-caloric food, low-caloric food, or control. Children who were pre-exposed to a high-caloric food ate more fruit than did those pre-exposed to a low-caloric food. These findings suggest that pre-exposure to high-caloric foods stimulates subsequent intake, including intake of foods that were not previously exposed, while pre-exposure to low-caloric foods does not appear to arouse appetite.     

Leptin intake during lactation prevents obesity and affects food intake and food preferences in later life

Breast milk is practically the only food ingested during the first months of life in fully breastfed infants and it is assumed to match the infant's nutritional needs. Epidemiological data suggest that breastfeeding compared with infant formula feeding confers protection against several chronic diseases later on in life and, particularly, against obesity and related medical complications. However, causality has not been related to any specific compound of breast milk. Recent data in our laboratory have identified leptin as the specific compound that is responsible for some of these beneficial effects of breastfeeding. The hormone leptin was identified as a key candidate because it is present in breast milk, but is not present in infant formula, and when ingested during the suckling period can be absorbed by the immature stomach exerting biological effects. Evidence of the beneficial effects of breast milk leptin was obtained from human studies, showing that milk-borne maternal leptin appeared to give moderate protection to infants from excess weight gain. Direct cause-effect evidence was obtained in rats, where oral leptin supplementation during the suckling period resulted in a decrease in food intake, affected food preferences in favour of carbohydrates versus fat, and protected against overweight in adulthood, with an improvement of related parameters such as leptin and insulin sensitivity. These findings open a new area of research on the use of leptin in the design of more appropriate infant formula, which is significant considering the increasing incidence of obesity and its associated medical complications.     

Measurement of children's food intake with digital photography and the effects of second servings upon food intake

This study tested the reliability and validity of measuring children's food intake with the digital photography method and the effects of second servings upon food intake. Food intake was measured in a school cafeteria for 5 days. Adiposity was assessed with body impedance analysis and body mass index, expressed as percentile rank. Mood and self-esteem were assessed with questionnaires. Estimates of food intake were highly reliable between two registered dietitians who independently estimated food intake. Boys ate more food than girls. A significant association between food intake and adiposity supported convergent validity. Non-significant correlations between food intake and depressed mood and self-esteem supported discriminant validity. When second servings were available, more food was selected and discarded, but mean food intake did not increase. Children who returned for second servings, however, ate more food when second servings were available, and a trend suggested that they also ate more food when second servings were not available. These findings support the reliability and validity of measuring children's food intake using digital photography and demonstrate its utility for studies of food intake and body weight.     

Plasma carotenoid response to chronic intake of selected foods and beta-carotene supplements in men.

We determined serial changes in four major plasma carotenoid fractions (alpha-carotene, beta-carotene, lutein/zeaxanthin, and lycopene) in 30 men consuming defined daily doses of carotenoids from foods (broccoli, carrots, or tomato juice) or from purified beta-carotene in capsules (12 or 30 mg) for 6 wk while fed a controlled diet. Compared with baseline, beta-carotene increased in the 30- and 12-mg-capsule and carrot groups whereas alpha-carotene increased in the carrot group and lutein increased in the broccoli group. Lower lutein concentrations in recipients of beta-carotene capsules suggested an interaction between these two carotenoids. Lycopene declined in all groups except the tomato-juice group. Total carotenoid concentration changes only reflected the large increases in beta-carotene concentrations and not the smaller changes observed in other individual carotenoids. Overall, purified beta-carotene produced a greater plasma response than did similar quantities of carotenoids from foods sources. However, some foods increased plasma concentrations of certain carotenoids.     

Eating rate of commonly consumed foods promotes food and energy intake

We investigated the eating rate of commonly consumed foods and the associations with food intake and macronutrient composition. Ingestion time (s) of 50 g of 45 foods was measured to assess eating rate (g/min), after which ad libitum food intake (g) was measured. Thirteen men and 24 women (aged 23.3 (SD 3.4)y, BMI 21.7 (SD 1.7)kg/m(2)) participated, each testing 7 foods in separate sessions. We observed large differences in eating rate between foods, ranging from 4.2 (SD 3.7) to 631 (SD 507)g/min. Eating rate was positively associated with food intake (β=0.55) and energy intake (β=0.001). Eating rate was inversely associated with energy density (β=-0.00047) and positively with water content (β=0.011). Carbohydrate (β=-0.012), protein (β=-0.021) and fiber content (β=-0.087) were inversely associated with eating rate, whereas fat was not. This study showed that when foods can be ingested rapidly, food and energy intake is high. People may therefore be at risk of overconsumption, when consuming foods with a high eating rate. Considering the current food supply, where many foods have a high eating rate, long-term effects of eating rate on energy balance should be investigated.     

Spanish children's diet: compliance with nutrient and food intake guidelines

OBJECTIVE: To compare the diet of Spanish children against the nutrient and food intake guidelines. To calculate an index of overall diet quality and check its validity against nutrient intake. DESIGN AND SETTING: Cross-sectional study in four cities in Spain, where information on food and nutrient intake was obtained from schoolchildren through a food frequency questionnaire. PARTICIPANTS: The sample included 1112 children (overall response rate of 85%) attending public and private schools and aged 6-7 y. Children were selected through random cluster sampling in schools, and stratified by sex and socioeconomic level. MAIN OUTCOME MEASURES: Mean nutrient intake, number of food servings, and the percentage of children who meet recommended nutrient and food-serving intake levels. The overall dietary quality was assessed using the Healthy Eating Index (HEI). RESULTS: Mean micronutrient intake exceeded 100% of the recommended dietary allowances, except for vitamin B6, which registered a mean intake of 77.1%. For almost all children, intake of saturated fat was above, and that of carbohydrate below, the recommended level, in contrast to the relatively high compliance with the recommendations for poly- and monounsaturated fatty acid, salt and fiber intake (69.7, 43.7, 40.7, and 30.1%, respectively). Consumption of food servings for each of the five American pyramid food groups came close to or exceeded USDA guidelines, with the exception of cereals, with 5.4 servings per day. The mean score obtained in the HEI was 64.6. Children who complied with all the food guide pyramid recommendations registered a higher dietary variety and a healthier nutritional profile. CONCLUSIONS: Children aged 6-7 y show scant compliance with the macronutrient goals for healthy eating. Micronutrient intake is adequate in general, yet there are small groups of children with risk of deficient intake of vitamins B6 and D. While Spanish children's eating habits are reasonably in line with American food guide pyramid guidelines, consumptions of cereals and fruit should be improved.     

Restricting minors' access to tobacco: a review of state legislation, 1991.

Currently, 46 states and the District of Columbia prohibit the sale of tobacco products to minors, and the minimum age requirement differs by state. In general, these laws are poorly enforced and inadequately prevent youth from obtaining tobacco. According to a four-part classification scheme used in this article, no states have comprehensive laws banning access to tobacco, four states have moderate laws, 37 states and the District of Columbia have basic laws, five states have nominal laws, and the remaining four states have no regulations. We recommend 11 important elements for laws that would adequately restrict minors' access to tobacco products.     

The effects of parental influences on children's food intake,physical activity,and relative weight

The current investigation assessed the relationship between observed child mealtime behavior, physical activity, selected parent behaviors, and child relative weight. Subjects were 30 (15 male, 15 female) preschool children varying in age from 22 to 46 months (mean = 30.5 months). Each subject and parents were observed during the dinnertime meal with an observational instrument designed to measure children's mealtime behaviors and parental influences on child eating. Further, children's activity levels were assessed for one hour and parental influences on child activity were observed. Results indicated that parental encouragements to eat correlated both with the percent of time the child ate and with child relative weight. Similarly, parental encouragements to be active correlated to extreme levels of child motor activity and negatively to relative weight. Implications of the current study are discussed and the present findings are compared and contrasted with previous research.     

Highly palatable food access during adolescence increased anxiety-/depression-like behaviors in male,but not in female,rats

Objectives: This study was conducted to examine the sexual dimorphic effects of highly palatable food (HPF) access during adolescence on the neurochemistry and depression-/anxiety-like behaviors of rats.

Methods: Male and female Sprague–Dawley pups had free access to chocolate cookie rich in fat (HPF) from postnatal day 28 in addition to ad libitum chow, and the control groups received only chow. The food conditions were continued throughout the entire experimental period, and the neurochemical and behavioral measurements were performed during young adulthood. Rats were subjected to the ambulatory activity, elevated plus maze, and forced swim tests. Corticosterone levels during 2?h of restraint stress were analyzed with radioimmunoassay, and ΔFosB and brain-derived neurotrophic factor (BDNF) expression in the nucleus accumbens (NAc) with Western blot analysis.

Results: Cookie access did not affect body weight gain and total caloric intake in both sexes; however, it increased retroperitoneal fat depot only in males. The time spent in open arms during elevated plus maze test was decreased and immobility during forced swim test was increased in cookie-fed males, but not in cookie-fed females. Main effect of food condition on the stress-induced corticosterone increase was observed in males, but not in females, and cookie access increased BDNF expression in the NAc only in males.

Conclusions: Increased BDNF expression in the NAc and fat depot, in addition to the stress axis dysfunction, may play roles in the pathophysiology of depression- and/or anxiety-like behaviors induced by cookie access.     

Measuring food access in Melbourne: access to healthy and fast foods by car, bus and foot in an urban municipality in Melbourne

Access to healthy food can be an important determinant of a healthy diet. This paper describes the assessment of access to healthy and unhealthy foods using a GIS accessibility programme in a large outer municipality of Melbourne. Access to a major supermarket was used as a proxy for access to a healthy diet and fast food outlet as proxy for access to unhealthy food. Our results indicated that most (>80%) residents lived within an 8-10 min car journey of a major supermarket i.e. have good access to a healthy diet. However, more advantaged areas had closer access to supermarkets, conversely less advantaged areas had closer access to fast food outlets. These findings have application for urban planners, public health practitioners and policy makers.     

Delta9-tetrahydrocannabinol stimulates palatable food intake in Lewis rats: effects of peripheral and central administration

To further study effects of delta9-tetrahydrocannabinol (THC) on food intake, male Lewis rats were maintained on rat chow and, on testing days, presented with chocolate cake batter (CCB) for 4h in addition to chow. Chow intake was not affected by THC administration in either experiment. In experiment 1 (n = 13) THC was administered intraperitoneally, and low doses produced increases in CCB intake for up to 1 h while the highest dose significantly decreased CCB intake over this same time period. In experiment 2 (n = 10) THC was injected intracerebroventricularly. Doses of 2.5, 10 and 25 microg significantly increased CCB intake for up to 1 h while stimulatory effects following 5 microg lasted up to 2h. Overall THC produced short-term increases in palatable food intake following both peripheral and central administration. Intraperitoneal administration resulted in an "inverted U" dose-response curve at all time points, while all central doses resulted in increased intake early in the time course and the hyperphagic effects were of greater duration than those following peripheral administration.