High-energy Foods Research Articles

Counseling parents on feeding their children

The high-nutrient needs of children for normal growth and development are matched by ready access to low-nutrient high-energy foods. Parents are often confused by new and at times conflicting information. This review discusses three recently published papers that offer specific and important dietary information for school-aged children. Lactose intolerance is common in some populations and there are misconceptions about dairy intake. Most lactose-intolerant children can consume some dairy products without symptoms. Fruit-juice intake can predict increased weight gain in children, especially those who are already overweight or at risk for being overweight. Hypertension is a serious disease with onset likely in childhood. This paper discusses the importance of dietary sodium as a contributor to the development of hypertension, and the sodium content of children's diets. Advice to parents on feeding children should be based on the food pyramid and include information on exercise. Recent publications suggest that children consume dairy products, even if lactose intolerant, restrict juice intake, remove sweetened beverages from their diets and reduce sodium consumption.

Comparison of grocery purchase patterns of diet soda buyers to those of regular soda buyers

The ultimate effect of regular and diet carbonated soft drinks on energy intakes depends on possible relations with other dietary components. With this motivation, this study compared grocery purchase patterns of regular and diet soft drink consumers using a large sample of US single-person households. We tested for differences in food-spending shares allocated to 43 food categories chosen mainly for their desirable/undesirable nutritional properties. We also investigated whether differences in purchased quantity of diet soft drinks are associated with differences in purchases of other food categories. We found a large number of significant differences, virtually all showing that more diet soda prone consumers make better nutrition choices, particularly regarding energy content. The study suggests that use of diet soft drinks does not lead to compensation by increased use of high-energy foods.

Mouse model of the metabolic syndrome: the quest continues

western lifestyle, with its unlimited consumption of high-energy food, has resulted in a pandemic of obesity and increased prevalence of cardiovascular disease. The first observations that overeating and obesity lead to poor metabolic outcomes, including diabetes mellitus, were made in the 1920s ([5

Metabolic syndrome and dietary habit

The importance of the concept ”metabolic syndrome” can be found in the changeover of mind-set. In a conventional approach, one's lifestyle improvement is forced for the first time after getting a disease. According to this concept, however, one's life-style improvement is to be advised actively at a stage before getting a disease. The diet therapy using this concept, which differs from the conventional one that gives a special prescription depending on one's specific disease, is based on diet guidelines recommended by academic societies for relevant diseases to be applicable and effective to such diseases. The first goal is reduction of visceral fat, more specifically, reduction of 5% of the initial amount of visceral fat so that the character of their fat cells qualitatively change. This diet therapy consulting covers over not only the eating habit but also physical exercises, appropriate controls of alcohol drinking and quitting smoking. Our diet advising focuses on modification of eating habit that tends to get more high-energy food, and guides people to have an eating habit to take an appropriate amount of energy. We use an action changing skill method for nutrition consultation, introducing a concept “food balance guide”, which teaches that the nutrition balance shall and can be realized by combining appropriate amount of staple food, side dish and some accompanying dishes. In many cases, no conventional diet therapy that requires an exact nutrition energy calculation is necessary. According to the reformation of medical administration system, which will be implemented in 2008, a person diagnosed as a metabolic syndrome will be obliged to follow a life-style consultation. The aim of this reformation is to reduce the burden of medical costs, namely, not to make people get ill. According to the relevant law, the public health nurses and national registered dietitians will be in charge of this consultation task. The position in society of the national dietitians, thus, will be estimated under the new medical administration system. In other words, I don't think it is an exaggeration to say that the future playing field of the dietitians and the national registered dietitians will be determined by the degree how they could contribute to the aim of the Health, Labor and Welfare ministry, namely, how they would contribute to reduce 25% of the number of persons in would-be life-style related diseases. I hope this confronting challenge will become a chance to their big break.

Interaction Between Orexins and the Mesolimbic System for Overriding Satiety

In North American society, it is all too common for the intake of calories to outweigh an individual's energy demands. Such over-consumption where high-energy foods are readily available undoubtedly contributes to the growing problem of obesity. Palatable food stimulates brain circuits similar to those that mediate behavioral responses to drugs of abuse, which may underlie the continuation of food intake long after energy requirements are met. Among the brain areas implicated in reward and food intake, the lateral hypothalamus (LH) has long been recognized as a common region involved in both. It has been suggested that orexin neurons that are expressed exclusively within and adjacent to the LH comprise a major cellular substrate for the functioning of the LH. Here, we review the idea that the orexin neuropeptides play a key role in the rewarding aspects of food intake through interactions with both peripheral and central signals reflecting current energy stores as well as the classic reward pathway--the mesolimbic dopamine system. Furthermore, a possible heterogeneity of orexin neurons is discussed. Uncovering orexin's role in food reinforcement may provide insight into hyperphagia and obesity. In addition, the idea that food intake and substance abuse involve similar brain circuitry suggests potential for a single treatment aiding both obesity and addiction.

Prevalence of obesity and its influencing factor among affluent school children of Davangere city

<b>Background: </b> Childhood obesity is a fast emerging problem for which national representative data is scarce. Effective preventive of adult obesity will require prevention and management of childhood obesity.<br><b> Objectives: </b> To know the prevalence of obesity in two affluent school children of Davangere city studying between 5th and 10th standard and to identify the factors influencing childhood obesity.<br><b> Methods: </b> A cross sectional study followed by a case control study was conducted in two affluent schools of Davangere city - Sri. Siddaganga and Sri. Taralabalu residential school. A total of 1496, school children studying between 5th & 10th standard aged between 10 and 15 years were enrolled and data on family history of obesity, diet, snacking habits and physical activity was collected.<br><b> Results: </b> Out of 1496 children 86 were obese. Prevalence of obesity was 5.74 %. Prevalence of obesity was more in girls (8.82%) than boys ( 4.42%). Prevalence of obesity increased, with increase in age in both boys and Girls. Family history of obesity, snacking of high energy foods and lack of physical activity were the important influencing factors of obesity. <br><b> Conclusion : </b> Consumption of high fat and high energy (Junk foods) and snacking in between the meals should be avoided by children. Health education should be given to parents, teachers and children regarding dietary habit and sedentary life style.

Foraging Strategy of Mouflon During the Hunting Season as Related to Food Supply

The aim of this study was to compare the diet composition based on rumen contents of mouflons from two localities differing in food supply. In northern Moravia (NM), secondary forests with dominance of conifers prevailed, whereas in southern Moravia (SM) forests with broad-leaved trees dominated. A total of 50 (NM, n = 23; SM, n = 27) quantitative and qualitative rumen analyses were carried out. In rumen specimens from both localities broad-leaved tree species predominated (NM 32.56% of volume; SM 38.92% v) during the autumn-winter season. Among the woody plants, ash was the most frequently consumed in both localities and in both diets approximately the same amount was found (17% v). In SM the mouflon consumed a high-energy diet of various seeds (34% v); acorns and horse chestnuts were the most abundant. Coniferous shoots were consumed in NM (14% v) twice as much as in SM (7% v). A higher number of food items (S = 70) and food diversity (H' = 3.49) was found in NM than in SM (S = 58; H'= 2.88). The quantitative similarity index (SI) of both diets (individual diet items) was low (SI = 39.12%). When calculated for the main diet groups the SI was higher (73.60%). The nutritional value (metabolisable energy) of the diet was correlated with diet quality (seeds, broad-leaved tree leaves). Mouflon is considered as a typical grazer but we found that during autumn and winter periods both Moravian subpopulations preferred browse and, where available, high-energy food for successful over-wintering. In SM the individuals had a non-significant tendency to be heavier and also their body fat content was higher (p = 0.035). The body condition of mouflons was thus related to the quality of the food supply in the biotope.

Disgust and fear ratings of eating disorder-relevant stimuli: Associations with dieting concerns and fat intake

The present study examines the relation between fear and disgust and dieting concerns. A sample of women completed measures of eating behavior, attitudes, fear, and disgust. They also provided emotional responses to images depicting high- and low-energy food, overweight and normal body shapes, and disgusting and frightening photographs. Fear and disgust of high-energy foods and overweight body shapes were significantly correlated with dieting concerns, but correlations between fear and disgust towards low-energy foods and slim body shapes were not. No significant correlations were found between eating behavior and emotional responses towards eating disorder-relevant or eating disorder-irrelevant stimuli. These findings suggest that while fear and disgust towards high–energy foods and overweight body shapes are related to dieting concerns, they do not mediate the relationship between dieting concerns and eating behavior. Emotional responses may represent rationalisations of dieting concerns rather than processes that support the avoidance of high-energy foods.

Changes in emotional state and cognition following administration of low-, medium- and high-energy foodstuff: the effect of dieting and dietary restraint

The aim of this study was to investigate changes in emotional state, food perception and cognition following administration of small quantities of low-, medium- or high-energy food. Thirty-eight female dieters and non-dieters aged 18–51 years (mean BMI=24.6 kg m−2) were asked to rate their emotional state before and after consumption and dietary restraint was determined using the Three-Factor Eating Questionnaire (Stunkard & Messick, 1985). The results showed that participants felt fuller and more energetic as energy content increased, whereas perception of “healthiness” and “safeness” of food decreased. Higher levels of anxiety were observed after ingestion of the medium-energy than after the low-energy food. Irrespective of the energy content, restrained eaters felt significantly more energetic than non-restrained eaters, whereas dieters reported significantly lower positive mood ratings than non-dieters following food administration. Although no significant effect of dietary restraint, dieting or energy content was observed on working memory, dieters’ performance was lower after consumption of a high-energy food. In conclusion, the study provided further evidence that energy content and psychological features of foods can alter emotional state and it can be tentatively suggested from these data that psychologically mediated changes in emotional responses to food and, more specifically, participants’ dieting behaviour should be taken into account when assessing the effects of nutrition on mood and cognition.

Superalimentação e desenvolvimento do esqueleto de cães da raça Dogue Alemão: aspectos clínicos e radiográficos

Estudou-se o efeito da superalimentação no desenvolvimento do esqueleto de 14 cães da raça Dogue Alemão, utilizando dieta hipercalórica (ração super-premium) associada ao método de alimentação à vontade. Os animais foram distribuídos em dois tratamentos, sendo a ração fornecida à vontade ou restrita. O consumo de alimento foi registrado diariamente e realizaram-se, mensalmente, radiografias do cotovelo e, bimestralmente, do ombro, do quadril e do carpo, visando acompanhar alterações do esqueleto, especificamente quanto ao aparecimento da osteocondrose do ombro e da metáfise distal da ulna, da osteodistrofia hipertrófica e da displasia coxofemoral (DCF). Ao final do experimento, seis cães do grupo que recebeu alimentação à vontade apresentaram-se gordos (87,7%) e um animal obeso (14,3%). Do grupo de alimentação restrita, três filhotes mostraram condição corporal ideal (42,8%), e quatro apresentaram-se magros (57,2%). O exame radiológico revelou alterações compatíveis com o diagnóstico de DCF nos dois grupos; nos alimentados à vontade, a prevalência foi de 51,1% e nos restritos, de 28,6%. A osteocondrose na metáfise distal da ulna, conhecida como retenção do núcleo cartilaginoso, foi observada apenas nos cães alimentados à vontade (57,1%). A superalimentação provocada pelo método de alimentação à vontade, associada com dieta de alta palatabilidade e alta densidade energética em filhotes da raça Dogue Alemão, induziu ao aparecimento de osteocondrose na metáfise distal da ulna e de displasia coxofemoral.

Controlling Obesity: What Should be Changed?

Edible fats are important food components that enhance palatability by providing texture and enhancing flavour. They also provide essential fatty acids and fat soluble vitamins. In addition, we enjoy eating foods containing fat, but there is also a negative side; excessive consumption may not be good for health, but we still have doubts to answer the question, What are the right amounts and types of fat we should use and eat?. The consumer is now aware of the relationship between dietary fat and health, but there is a great deal of confusion. One of the well-known problems of the increase in fat intake is the higher prevalence of overweight and obesity in all the industrialized countries, for the adults but specially for the children. Several questions arise... What are the health implications of this phenomenon? The health implications include usually a combination of increased risk of cardiovascular diseases, type 2 diabetes, some cancers, arthritis, gallstones, and mental problems. The health implications for the nations could see the start of a decline in longevity. What are the causes of the recent rise in obesity? Individual's energy balance changes due to less energy expanded compounded by more being consumed. What can be done about it? There are three main components driving obesity: First and second, the ubiquitous availability of high energy food as well as a decline in everyday activity. The third is a controlling factor in that humans evolved in an environment prone to food shortages. In fact, our natural drivers are geared to consuming more than we need. Our natural checks serve to answer to hunger and much less to excess. Consequently the ready availability of energy dense foods and decline in metabolic activity both serve to drive obesity. A recent report from WHO (2003) point that the increase in the quantity and quality of the fats consumed in the diet is an important feature reflected in the national diets of countries. An important point is that there has been a remarkable increase in the intake of dietary fats over the past three decades and that this increase has taken place everywhere except in Africa. In fact, the increase in dietary fat supply worldwide exceeds the increase in dietary protein supply. The average global supply of fat has increased by 20 g per capita since 1960's, more pronounced in the Americas, East Asia, and the European Community. An important issue not enough considered is related to the contribution of expanding portion sizes to the obesity epidemic. Many observations hint that portions sizes are increasing. We should remember that larger portions not only contain more energy but also encourage people to eat more, which makes more difficult to balance static levels of physical activity. Marketplace food portions have increases in size universally and exceed the recommended standard ones. Educational and other public health efforts to address obesity should focus on the need for people to consume smaller portions. Another questions that should be discussed but difficult to answer are: What role can the food industry, marketing and advertising play? And schooling? And to what extent can and should the Governments influence lifestyle choices? "Knowing is not enough; we must apply. Willing is not enough; we must do" Goethe.

The Nutrition Transition in American Indians

The purpose of this article was to examine whether a nutritional transition has occurred among American Indians (AI) by evaluating related articles and government health statistics. Findings indicate that although the primary health risk for the AI population around 1970 was undernutrition, now there is an obesity epidemic among all age groups that is associated with a loss of traditional food practices and reduced physical activity. Deaths caused by cardiovascular disease, diabetes mellitus, and cancer have outpaced death from infectious disease. With abundant high-energy foods and limited physical activity, the acculturated environment has resulted in obesity and increased mortality from chronic diseases. To improve AI health and survival, the obesity epidemic must be approached in a concerted, culturally appropriate manner with encouragement of traditional foods and safe opportunities for physical activity.

Diet-dependent shifts in ruminal butyrate-producing bacteria

The influence of a host's diet on Butyrivibrio and Pseudobutyrivibrio populations was investigated by competitive PCR. Specific primers were designed and competitive PCRs developed for both groups. Results (from 4 cows with different diets) suggested that high-fiber intake essentially increases the Butyrivibrio amounts in the rumen, whereas high-energy food additives lead to its suppression. The Pseudobutyrivibrio concentration also changed during the experiment but without any significant relation to the host's diet.

An Adapted Method for Sampling Earthworms at Night in Wildlife Studies

Earthworms are a major food item of many vertebrates, and their high biomass in temperate ecosystems provides an abundant and high-energy food resource. Earthworm tissue has a protein content of 60–70% (dry weight) with a high amino-acid content that is well matched to the requirements of vertebrates (Lee 1985). In the Western Palearctic, earthworms are a regular part of the diet of 186 mammal-, bird-, reptile-, and amphibian-predator species (Granval and Aliaga 1988). Specifically, earthworms of the family Lumbricidae are the main prey of many nocturnal animals, including 8 species of bird (belonging to families Rallidae, Charadriidae, Scolopacidae, and Strigidae), 5 species of mammal: badgers (Meles meles), hedgehogs (Erinaceus europaeus), moles (Talpa europaea), and 2 shrews (Sorex araneus and Neomys fodiens), and 19 species of amphibian (Granval and Aliaga 1988). The predominance of vertebrate earthworm predators foraging at night is likely to be the result of a higher overall abundance of earthworms near the soil surface at night than during the day. Certain earthworms (especially anecic species, known as night crawlers) perform nocturnal vertical migrations, where they emerge from the soil and move on the surface during the night (Lee 1985). Earthworms are very sensitive to bright light and ultraviolet radiation (Edwards and Lofty 1972). Thus, earthworms come to the soil surface at night or during periods of very low light intensity during the day (late in the evening or early in the morning), to mate or in search of organic food litter (Lee 1985). Many ecological and behavioral studies (time–budget studies, energetic studies, optimal foraging theory) require data on the abundance and availability of prey species. However, it is time consuming and logistically difficult to collect such data on subterranean species such as earthworms. Earthworms are usually sampled according to the standardized method described by Bouche and Gardner (1984) and Bouche and Aliaga (1986), which gives an accurate estimate of earthworm biomass. This method combines 2 complementary extraction techniques: 1) a chemical extraction using diluted formalin, which makes earthworms surface, is sprayed either on bare soil or on short-cut grass and 2) a physical extraction of worms that did not respond to the formalin and/or died near the surface from soil cores. However, such a method can only be correctly used in the daylight because worms forced from the soil by the formalin are very difficult to find and collect at night with portable headlamps. Moreover, earthworm populations are known to be highly aggregated in patches (Poier and Richter 1992, Rossi et al. 1997) and samples spaced only a few meters apart can give large differences in abundance of earthworms. Hence, to account for the spatial heterogeneity of worms, it is generally advised to sample several plots (usually 3–6) at the same site (Lee 1985). Because this technique requires 45 min of formalin spraying per m plus 15 min of preparation time (grass cutting), it is extremely time consuming. Thus, sampling can take many hours depending upon the number of plots sampled. Such a long, involved sampling time is generally not compatible with the work of individual wildlife researchers, who need easy and fast methods to estimate the availability of prey to predators, and not necessarily the exact biomass of prey in the habitat. A habitat containing a high biomass of earthworms (measured by standard procedure) may be of little interest to the predator if prey are too deep to be captured. For example, shorebirds, like Eurasian oystercatchers (Haematopus ostralegus), are limited by the size of their bill and choose prey (bivalves) at a well-defined depth in the mud; therefore, knowing the total biomass of bivalves is useless if only the most superficial ones are potential prey (Zwarts et al. 1996). To our knowledge, the availability of earthworms at night has not yet been quantitatively assessed, and no study has focused on the reliability of the diurnal standard method for estimating nocturnal earthworm availability. We describe an original yet simple method to sample earthworms, designed for wildlife biologists studying nocturnal vertebrate predators. We tested this new sampling procedure as part of an ecological study on the Eurasian woodcock (Scolopax rusticola), a bird that mainly forages on earthworms. The few studies on habitat selection in woodcocks (including the closely related American woodcock, Scolopax minor) found a correlation between habitat selection and earthworm availability, in summer and winter (Hudgins et al. 1985, Hirons and Johnson 1987, Granval and Bouche 1993, Duriez et al. 2005c). On winter nights woodcocks use fields extensively, especially meadows (Cramp and Simmons 1983), which are among the richest habitats for earthworms in Europe (Edwards 1983, Binet and Trehen 1990, Binet 1993, Fraser 1994). Because woodcocks have a maximum 1 E-mail: o.duriez@wanadoo.fr

Effects of Supplemental Feeding on Physiological Condition of Northern Bobwhite in South Texas

The effects of supplemental feeding on populations of northern bobwhites (hereafter, bobwhite) have been the subject of many previous studies (Frye 1954; Keeler 1959; Robel et al. 1974; Doerr and Silvy 1987; DeMaso et al. 1998, 2002; Townsend et al. 1999). Burger and Linduska (1967), Ellis et al. (1969), and Guthery (1997) noted that supplemental feeding and food plots have not produced a positive population response for bobwhites. However, Lehmann (1984:16, 276) suggested that bobwhites benefited from feeding in south Texas, USA, and Guthery (1986:48–59) suggested that supplemental feeding could benefit bobwhite reproduction and survival if habitat structure was of sufficient quality and the feeding program was handled correctly. Guthery (2002) now tempers his 1987 position about supplemental feeding and other means of habitat quality enhancement, by supporting maximizing habitat quantity over habitat quality. Townsend et al. (1999) suggested that bobwhites can gain nutritional benefits from supplemental feeders during times of severe winter stress. Doerr and Silvy (2002) reported that supplemental feeding with whole milo increased survival of birds on deep-sand-range sites, but it did not increase bobwhite densities the following fall. Feeding did not affect bobwhite density or survival on clay soils of the Gulf Coast or on red-sand loams of south Texas. Doerr and Silvy (2002) also found that whole milo supplied from winter through early spring did not increase reproductive success on any of their study areas. Improved food supply has been hypothesized to result in better body condition or reduced danger to stress or predation, thus increasing survival (Doerr 1988). Improved food supply may alter time of reproduction, increase realized reproductive effort, or improve nurturing efforts. Stress in bobwhites is reflected by weight loss (Robel 1972; Robel et al. 1974, 1979), reduced fat reserves (Robel 1969, 1972; Robel et al. 1974, 1979), and increased mortality (Robel 1965, Robel and Fretwell 1970, Robel et al. 1979). Kendeigh (1969, 1970) proposed that demands by birds to maintain core body temperatures caused a greater depletion on fat reserves. Leif and Smith (1993) noted that bobwhites feeding on low-energy foods accumulated less body fat than those feeding on high-energy foods. Robel et al. (1974) reported that bobwhites having access to food plots during late winter in Kansas accumulated more body fat compared to birds not having access to food plots. We monitored bobwhite body condition in response to fall feeding of a high-energy supplement (milo) in south Texas. Specifically, we studied the effects of supplemental feeding on the physiological condition of bobwhites in fed and nonfed sites in south Texas. We hypothesized that wild birds fed supplemental whole milo would have greater body fat content than birds not fed supplemental milo.

Captive female gorilla agonistic relationships with clumped defendable food resources

Minimal feeding competition among female mountain gorillas (Gorilla gorilla beringei) has resulted in egalitarian social relationships with poorly defined agonistic dominance hierarchies. Thus, gorillas are generally viewed as non-competitive egalitarian folivores that have had little need to develop effective competitive strategies to access food resources. However, this generalization is inconsistent with more recent research indicating that most gorillas are frugivorous, feeding on patchily distributed food resources. The current study at Howletts Wild Animal Park, Kent, England, explores the effects of clumped and defendable foods on female gorilla agonistic relationships among three groups of western lowland gorillas (G. g. gorilla), conditions that are predicted to lead to well-differentiated agonistic dominance hierarchies among female primates. The Howletts gorillas foraged all day on low-energy/-nutrient, high-fiber foods widely distributed around their enclosure by the keepers. However, they also had periodic access to high-energy foods (e.g., nuts, raisins, strawberries, etc.) that the keepers would spread in a clumped and defendable patch. Frequencies of agonistic and submissive behaviors between females and proximity data were gathered. High-status females were found to monopolize the food patch and kept the low-status females at bay with cough-grunt threat vocalizations or by chasing them away. Agonistic interactions were initiated mostly by females of high status; these were directed towards females of low status and were generally not reciprocal. In addition, females of low status engaged in submissive behaviors the most often, which they directed primarily at females of high status, especially in response to aggression by the latter. Agonistic interactions between high- and low-status females had decided outcomes more often than not, with low-status females the losers. Competition over highly desirable foods distributed in defendable clumps at Howletts appears to have led to well-defined dominance relationships among these female gorillas.

Neural representations of hunger and satiety in Prader–Willi syndrome

To investigate the neural basis of the abnormal eating behaviour in Prader-Willi syndrome (PWS), using brain imaging. We predicted that the satiety response in those with PWS would be delayed and insensitive to food intake. The design of this study was based on a previous investigation of the neural activation associated with conditions of fasting and food intake in a nonobese, non-PWS group. The findings were used to generate specific hypotheses regarding brain regions of interest for the current study, in which 13 adults with PWS took part (mean +/- s.d. age = 29 +/- 6; BMI = 31.5 +/- 5.1; IQ = 71 +/- 8, six were female). Regional cerebral blood flow was measured using positron emission tomography in three sessions: one following an overnight fast and two following disguised energy controlled meals of similar volume and appearance--one of 1674 kJ (400 kcal) and another of 5021 kJ (1200 kcal). Subjective ratings of hunger, fullness and desire to eat, and blood plasma levels of glucose, insulin, leptin, ghrelin and PYY were measured before and after each imaging session. The neural representation of hunger, after an overnight fast, was similar to that found in nonobese individuals in the control study. In contrast, after food intake, the patterns of neural activation previously associated with satiety were not found, even after the higher-energy load. Lateral and medial orbitofrontal cortical activation was associated with consumption of the 400- and 1200-kcal meals, respectively. The medial orbitofrontal activation, however, was only found in those who had shown a large percentage change in fullness ratings following the higher-energy meal. We conclude that there is a dysfunction in the satiety system in those with PWS. These findings suggest that brain regions associated with satiety are insensitive even to high-energy food intake in those with the syndrome. This may be the neural basis of the hyperphagia seen in PWS.

Does regular walnut consumption lead to weight gain?

Studies consistently show the beneficial effects of eating nuts, but as high-energy foods, their regular consumption may lead to weight gain. We tested if daily consumption of walnuts (approximately 12 % energy intake) for 6 months would modify body weight and body composition in free-living subjects. Ninety participants in a 12-month randomized cross-over trial were instructed to eat an allotted amount of walnuts (28-56 g) during the walnut-supplemented diet and not to eat them during the control diet, with no further instruction. Subjects were unaware that body weight was the main outcome. Dietary compliance was about 95 % and mean daily walnut consumption was 35 g during the walnut-supplemented diet. The walnut-supplemented diet resulted in greater daily energy intake (557 kJ (133 kcal)), which should theoretically have led to a weight gain of 3.1 kg over the 6-month period. For all participants, walnut supplementation increased weight (0.4 (se 0.1) kg), BMI (0.2 (se 0.1) kg/m(2)), fat mass (0.2 (se 0.1) kg) and lean mass (0.2 (se 0.1) kg). But, after adjusting for energy differences between the control and walnut-supplemented diets, no significant differences were observed in body weight or body composition parameters, except for BMI (0.1 (se 0.1) kg/m(2)). The weight gain from incorporating walnuts into the diet (control-->walnut sequence) was less than the weight loss from withdrawing walnuts from the diet (walnut-->control sequence). Our findings show that regular walnut intake resulted in weight gain much lower than expected and which became non-significant after controlling for differences in energy intake.

Socio-demographic differences in food habits and preferences of school adolescents in Jiangsu Province, China

To identify the differences in food habits and preferences among the adolescents according to socio-demographic characteristics. Cross-sectional, cluster design survey in 2002. Eight middle schools in two distinct socio-economic areas of the Jiangsu province, China. Some 824 young adolescents (12-14 y) attending public schools with a response rate of 99%. A self-administered questionnaire containing questions on food and meal frequencies, food preferences and socio-demographic characteristics was used. High socio-economic status (SES) and urban residence was positively associated with intake of high-energy foods, such as foods of animal origin, Western style foods and dairy products. In all, 76% of the students had three meals a day regularly , but 8.1% urban students vs 3.4% rural students had breakfast only 1-3 times per week or less often. Daily fruit consumption was fairly common, but with clear differences by SES. Only about 42% of the boys and 55% of the girls from low SES families ate fruit daily, compared with 66% and 72%, respectively in the high SES families. Urban boys had the lowest proportion of daily consumers of vegetables (67.0%). More urban students drank milk daily than the rural students (68.7 vs 38.5%). The frequency of milk drinking also showed a strong positive association with SES. About 10% of the high SES boys consumed hamburgers daily compared with 2.8% of the low SES boys. More than half of the students reported a liking for Western style fast foods including hamburgers, soft drinks and chocolate. Among high SES boys, 21.5% consumed soft drinks on a daily basis; however, as many as 72.3% wanted to drink soft drinks more often if they could afford it. SES and urban location were positively associated with frequency of intake of high-energy foods. Reported food preferences may enforce this trend. Nutrition education for adolescents and parents is needed to promote healthy eating. Health Authorities should strengthen the monitoring of food intake and its association with overweight/obesity. This study was funded by the Norwegian Directorate of Health and Social affairs under the auspices of the Norway-China Health Agreement.

Adaptation to a High-Fat Diet Leads to Hyperphagia and Diminished Sensitivity to Cholecystokinin in Rats

Rats fed high-fat (HF) diets exhibit reduced sensitivity to some peptide satiety signals. We hypothesized that reduced sensitivity to satiety signals might contribute to overconsumption of a high-energy food after adaptation to HF diets. To test this, we measured daily, 3-h intake of a high-energy, high-fat (HHF, 22.3 kJ/g) test food in rats fed either low-fat (LF) or HF, isoenergetic (16.2 kJ/g) diets. During testing, half of each group received the HHF test food (LF/HHF; HF/HHF), whereas the other half received their respective maintenance diet (LF/LF; HF/HF). Rats fed a HF diet ate more of the HHF food during the 3-h testing period than LF-fed rats (HF/HHF = 7.7 +/- 0.3 g vs. LF/HHF = 5.5 +/- 0.2 g; P = 0.003). Rats tested on their own maintenance diets had similar intakes (HF/HF = 3.2 +/- 0.2 g vs. LF/LF = 3.7 +/- 0.3 g), which were lower (P < or = 0.008) than intakes of rats tested on HHF. HHF-tested rats did not differ in body weight by the end of wk 2 of testing. In a subsequent short-term choice preference test, rats exhibited an equal relative preference for HHF irrespective of their maintenance diets (HF = 63.1%, LF = 68.1%, P = 0.29). Finally, we examined the effect of intraperitoneal NaCl or cholecystokinin (CCK)-8 (100 and 250 ng/kg) injection on 1-h food intake. Both doses of CCK significantly suppressed food intake in LF-fed rats but not HF-fed rats. These results demonstrate that chronic ingestion of a HF diet leads to short-term overconsumption of a high-energy, high-fat food compared with LF-fed cohorts, which is associated with a decreased sensitivity to CCK.