Effects of diets high in whey, soy, red meat and milk protein on body weight maintenance in diet-induced obesity in mice

This study examined the effects of different food sources of protein on energy intake, body weight maintenance, and on the responses of plasma leptin, insulin and adiponectin in chronic high-fat diet-induced obese mice. Obesity was induced in 47 mice with a high-fat diet for 20 weeks. They were divided into five diet groups to test the effects of a higher protein proportion (30% energy), achieved at the expense of carbohydrate. For the next eight weeks, four of the groups were fed diets of chow formulated with whey, soy, red meat or milk while the control group continued on their high-fat diet. The results showed that: (i) increasing the protein : carbohydrate ratio (both at 30% energy) in a high-fat diet did not reduce the level of obesity; (ii) the type of protein added, however, did have a significant effect on the level of obesity attained; (iii) whey protein stabilised weight gain the most, had the strongest satiety effects and also stimulated the highest production of adiponectin; and (iv) whey protein also was associated with the lowest insulin values among all proteins tested. Plasma leptin levels were not affected by any of the diets. Dietary fat remains a potent factor in weight management, but the type and amount of protein may also be important through its effects on food intake. In particular, the apparent decreased appetite associated with increased adiponectin in the whey-based high-protein diet may contribute to stabilised body mass in chronic high-fat diet-induced obesity.

Fast food purchasing and access to fast food restaurants : a multilevel analysis of VicLANES

Background : While previous research on fast food access and purchasing has not found evidence of an association, these studies have had methodological problems including aggregation error, lack of specificity between the exposures and outcomes, and lack of adjustment for potential confounding. In this paper we attempt to address these methodological problems using data from the Victorian Lifestyle and Neighbourhood Environments Study (VicLANES) – a cross-sectional multilevel study conducted within metropolitan Melbourne, Australia in 2003.
Methods : The VicLANES data used in this analysis included 2547 participants from 49 census collector districts in metropolitan Melbourne, Australia. The outcome of interest was the total frequency of fast food purchased for consumption at home within the previous month (never, monthly and weekly) from five major fast food chains (Red Rooster, McDonalds, Kentucky Fried Chicken, Hungry Jacks and Pizza Hut). Three measures of fast food access were created: density and variety, defined as the number of fast food restaurants and the number of different fast food chains within 3 kilometres of road network distance respectively, and proximity defined as the road network distance to the closest fast food restaurant. Multilevel multinomial models were used to estimate the associations between fast food restaurant access and purchasing with never purchased as the reference category. Models were adjusted for confounders including determinants of demand (attitudes and tastes that influence food purchasing decisions) as well as individual and area socio-economic characteristics.
Results : Purchasing fast food on a monthly basis was related to the variety of fast food restaurants (odds ratio 1.13; 95% confidence interval 1.02 – 1.25) after adjusting for individual and area characteristics. Density and proximity were not found to be significant predictors of fast food purchasing after adjustment for individual socio-economic predictors.
Conclusion : Although we found an independent association between fast food purchasing and access to a wider variety of fast food restaurant, density and proximity were not significant predictors. The methods used in our study are an advance on previous analyses.

Effect of a low-fat diet on fatty acid composition in red cells, plasma phospholipids, and cholesterol esters : investigation of a biomarker of total fat intake

Background: The utility of fatty acids (FAs) as biomarkers of total fat intake is unknown.

Objective: We compared FA changes in red cells (RCs), plasma phospholipids (PLs), and cholesterol esters (CEs) in response to a low-fat diet (LFD) and a moderate-fat diet (MFD) and assessed whether individual or combination of FAs predict LFD.

Design: Postmenopausal women (n = 66) were randomly assigned to receive an LFD (17% of energy from fat) or an MFD (34% of energy from fat) for 6 wk. All foods were provided. FAs in diets and blood were determined by gas-liquid chromatography. FA changes between baseline and end of study were compared across diets by using t tests. FA predictors of an LFD were selected by logistic regression.

Results: Many FAs in RCs, PLs, and CEs responded differently to the 2 diets. Changes from baseline with an LFD for palmitic acid (16:0) (3–11% increase), behenic (22:0) and lignoceric (24:0) acids (3–20% decrease, in RCs and PLs only), cis-monounsaturated FA (MUFA) (25–35% increase), linoleic acid (18:2n–6) (11–13% decrease), trans octadecanoic acids (trans 18:1) (7–20% decrease), and n–6 highly unsaturated FA (HUFA) (2–8% increase) were significantly different from changes with an MFD. Individually, 18:2n–6 and trans 18:1 were strong predictors of an LFD [receiver operating characteristic (ROC) curves: 0.92–0.80). A logistic regression model with trans 18:1, 18:2n–6, and vaccenic acid (18:1n–7) predicted an LFD with high specificity and sensitivity (ROC curves: 0.99).

Conclusions: Saturated FA, cisMUFA, n–6 HUFA, and exogenous FAs greatly differed in their response to the LFD and MFD. Parallel responses were observed in RCs, PLs, and CEs. A model with a combination of FAs almost perfectly differentiated the consumption of 34% fat from that of 17% fat.

Family food environments as determinants of children's eating : implications for obesity prevention

The prevalence of childhood obesity is escalating rapidly and it considered to be a major public health problem. Diet is a recognised precursor of fatness, and current evidence supports the premise that in Westernised countries, the dietary intakes of children are likely to be important in obesity genesis. However, we have a relatively poor understanding of the environments in which a child’s eating is learnt and maintained. Much of the existing work in this area is based on small-scale or experimental studies, or has been derived from homogeneous populations within the USA. Despite these limitations, there is evidence that aspects of the child’s family environment are likely to be important in determining obesity risk in children. This thesis examines the impact of the family food environment on a child’s eating through two related studies. The first study, titled the Children and Family Eating (CAFÉ) study comprised three phases. Phase one involved qualitative interviews with 17 parents of 5-6 year-old children to explore parental perceptions regarding those factors in a child’s environment believed to influence the development of their child’s eating habits. These interviews were used to inform the development of quantitative measures of the family food environment. The second phase involved the development of a Food Frequency Questionnaire (FFQ) to assess dietary intake in 5-6 year-olds. The FFQ was informed by analysis of 1995 Australian National Nutrition Survey data. In the final phase the relationships between dietary intakes of 5-6 year-old children, and potential predictors of dietary intake were examined in a cross-sectional study of 560 families. Predictors included measures of: parental perceptions of the adequacy of their child’s diet; food availability and accessibility; child-feeding; the opportunities for parental modelling of food intake; a child’s television exposure; maternal Body Mass Index; and maternal education. Analysis of the CAFÉ data provides unique information regarding the relationships between a child’s family food environment and their food consumption. Models developed for a range of dietary outcomes considered to be predictive of increased risk for obesity, including total energy and fat intakes, vegetable variety, vegetable consumption, and high-energy (non-dairy) fluid consumption, explained between 11 and 20 percent of the variance in dietary intake. Two aspects of the family food environment, parental perception of a child’s dietary adequacy, and the total minutes of television viewed per day, were frequently found to be predictive of dietary outcomes likely to promote fatness in these children. The second study, titled the Parent Education and Support (PEAS) Feeding Intervention Study, was a prospective pre/post non-randomised intervention trial that assessed the impact of a feeding intervention to 240 first-time mothers of one-year-old children. This intervention focused on one aspect of the family food environment, child-feeding, which has been proposed as influential in the development of obesogenic eating behaviours. In this study, Maternal and Child Health Nurses (MCHNs), using a ‘Division of Responsibility’ model of feeding, taught parents to provide nutritious food at regular intervals and to let children decide if to eat and how much to eat. Thus parents were encourages to food their child without exerting pressure, or employing coercion or rewards (controlling behaviours). The aim was to influence parental attitudes and beliefs regarding child-feeding. Through the use of these feeding techniques, this intervention also aimed to increase the variety of fruits and vegetables a child consumed by teaching parents to persist with offering these foods, over the year of the intervention, in non-emotive environments. Fruits and vegetables were chosen in this intervention because they are likely to be protective in the development of obesity. Analysis of the PEAS data suggests that this low-level feeding intervention, delivered through existing Maternal and Child Health services, was modestly effective in changing parental attitudes and beliefs regarding the feeding of young children. Further, the validity of fruits offered to intervention group children increased. This thesis expands the existing knowledge base by providing a comprehensive analysis of the relative impact of aspects of the family environment on dietary intakes of 5-6 year-olds. Further, the analysis of a feeding intervention in first-time parents provides important insights regarding the potential to influence child-feeding and the impact this may have on the promotion of eating behaviours protective against obesity.

Resource partitioning in sympatric populations of Red-necked Wallabies and Black Wallabies

Examines the potential for competition to occur between the Red-necked Wallaby and the Black Wallaby by examining the extent of overlap in their dietary preferences and in their utilisation of habitat at different times of the day and year. Significant separation occured between species to facilitate coexistence.

Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women

The possibility that the heightened cardiovascular risk associated with the menopause can be reduced by increasing dietary isoflavone intake was tested in 17 women by measuring arterial compliance, an index of the elasticity of large arteries such as the thoracic aorta. Compliance diminishes with age and menopause. An initial 3- to 4-week run-in period and a 5-week placebo period were followed by two 5-week periods of active treatment with 40 mg and then 80 mg isoflavones derived from red clover containing genistein, daidzein, biochanin, and formononetin in 14 and 13 women, respectively, with 3 others serving as placebo controls throughout. Arterial compliance, measured by ultrasound as a pressure (carotid artery) and volume (outflow into aorta) relationship, was determined after each period; plasma lipids were measured twice during each period. Urinary output of isoflavones was also determined. Arterial compliance rose by 23% relative to that during the placebo period with the 80-mg isoflavone dose and slightly less with the 40-mg dose (mean6SEM: placebo, 19.761.5; 40 mg, 23.760.7; 80 mg, 24.46 1.4). In the three women receiving continuous placebo, compliance was 16 6 2.2, similar to that during the run-in period for the remaining subjects (17 6 2.1). ANOVA showed a significant (P 5 , 0.001) difference between treatments; by Bonferroni multiple comparisons and by paired t test, differences were significant between placebo and 40- and 80-mg isoflavone doses (by paired t test: P50.039 for placebo vs. 40 mg; P 5 0.018 for placebo vs. 80 mg). Plasma lipids were not significantly affected. An important cardiovascular risk factor, arterial compliance, which diminishes with menopause, was significantly improved with red clover isoflavones. As diminished compliance leads to systolic hypertension and may increase left ventricular work, the findings indicate a potential new therapeutic approach for improved cardiovascular function after menopause.

Trends in food intake in French children from 1999 to 2007 : results from the INCA (étude Individuelle Nationale des Consommations Alimentaires) dietary surveys

The objectives of the present study were to assess the intake of different food groups in French children aged 3–17 years (n 1455), and to analyse trends since a dietary survey undertaken 8 years ago. Dietary intake was evaluated using data from the 2006–7 cross-sectional INCA2 national dietary survey (étude Individuelle Nationale sur les Consommations Alimentaires), based on a 7 d food record. Dietary intake (percentage of subjects consuming the food group and amount eaten) was assessed for thirty-nine food categories. We observed variations in food consumption by age, sex, North–South regional gradient, seasonal period and educational level of the responding parent. Trends in dietary intake between 1999 and 2007 were determined by comparing the INCA1 (n 1126) and the INCA2 surveys. Both surveys had been carried out using the same methodology. The findings showed a decrease in energy intake in children aged 3–14 years, due to a reduction in the consumption of foods of animal origin and sweetened products. In adolescents aged 15–17 years, energy intake remained rather stable; during this 8-year period, the consumption of meat decreased, whereas the consumption of savoury snacks such as sandwiches and hamburgers significantly increased. These trends occurred during a time of growing concern about overweight and the associated co-morbidities in France. A number of public health measures were implemented over this period to improve dietary habits and physical activity patterns in children and adults. The periodic monitoring of dietary patterns through the INCA surveys is an essential part of the surveillance network in France.

Socio-economic and demographic variations in school lunch participation of French children aged 3-17 years

Objective: To assess school canteen attendance in a French nationally representative sample of children and to analyse its association with the socioeconomic and demographic characteristics of the children and their families.
Design: Data from the second French national cross-sectional food consumption survey (INCA2), performed in 2006–2007, were used. Information on usual weekly school canteen attendance was collected through a self-reported questionnaire, and demographic and socio-economic variables through a face-to-face questionnaire. The associations between school canteen attendance and the socio-economic and demographic variables were investigated by multivariate logistic regression analyses.
Setting: The INCA2 sample was representative of the children aged 3–17 years in France.
Subject: Analysis was performed on 1413 schoolchildren who completed the school canteen attendance questions.
Results: Some 65?6% of schoolchildren aged 3–17 years had school lunch at least once weekly. This rate of attendance was positively correlated with age. Whatever the school level, school canteen attendance was positively associated with the educational level of the caregiver/parent. In pre- and elementary-school children, enrolment at the school canteen was also higher when the caregiver/parent worked, or in single-parent families. In secondary-school children, school lunch participation decreased with children living in more densely populated areas and increased with the level of the household’s living standards.
Conclusions: School canteen attendance was positively associated with children’s socio-economic background. This could reduce the effectiveness of the forthcoming school meal composition regulations designed to improve the diet of children from deprived backgrounds, who are more likely to have unhealthy food habits.

Many routes lead to Rome : potential causes for the multi-route migration system of Red Knots, Calidris canutus islandica

Migrants, such as birds or representatives of other taxa, usually make use of several stopover sites to cover the distance between their site of origin and destination. Potentially, multiple routes exist, but often little is known about the causes and consequences of alternative migration routes. Apart from their geographical distribution, the suitability of potential sites might play an important role in the animals’ decisions for a particular itinerary. We used an optimal-migration model to test three nonmutually exclusive hypotheses leading to variations in the spring migration routes of a subspecies of Red Knot, Calidris canutus islandica, which migrates from wintering grounds in Western Europe to breeding grounds in Greenland and the Canadian Arctic: the breeding location hypothesis, the energy budget hypothesis, and the predation risk hypothesis. Varying only breeding location, the model predicted that birds breeding in the Canadian Arctic and on West Greenland stop over on Iceland, whereas birds breeding in East and Northeast Greenland migrate via northern Norway, a prediction that is supported by empirical findings. Energy budgets on stopover sites had a strong influence on the choice of route and staging times. Varying foraging-intensity and mass-dependent predation risk prompted the birds to use less risky sites, if possible. The effect of simultaneous changes in the energy budget and predation risk strongly depended on the site where these occurred. Our findings provide potential explanations for the observations that C. canutus islandica uses a diverse array of migration routes. Scrutinizing the three alternative driving forces for the choice of migratory routes awaits further, specific data collection in rapidly developing fields of research (e.g., predation risk assessment, GPS tracking). Generally, the type of modeling presented here may not only highlight alternative explanations, but also direct follow-up empirical research.

Government food service policies and guidelines do not create healthy school canteens

Objective
In 2006, the Victorian Government adopted the School Canteens and other school Food Services (SCFS) Policy that bans the sale of sweet drinks and confectionary and recommends the proportions of menu items based on a traffic light system of food classification. This study aims to determine whether compliance with the policy improves the nutritional profile of the menus.
Methods
Items from food service menus were assessed for compliance with the SCFS policy and categorised as ‘everyday’ (‘green’), ‘select carefully’ (‘amber’) or ‘occasionally’ (‘red’) (n=106). Profile analysis assessed differences in the nutritional profile of the menus between sub-groups.
Results
Overall, 37% of menus contained items banned under the policy. The largest proportion of items on the assessed menus were from the ‘amber’ category (mean: 51.0%), followed by ‘red’ (29.3%) and ‘green’ (20.3%). No menus met the traffic light-based recommendations and there was no relationship between policy compliance and the proportion of items in each of the three categories.
Conclusions and implications
To increase the healthiness of the school food service we recommend a greater investment in resources and infrastructure to implement existing policies, and establishing stronger monitoring and support systems.

Do Red Knots (Calidris Canutus Islandica) routinely skip Iceland during southward migration?

Subspecies Calidris canutus islandica of the Red Knot breeds on the arctic tundra of northeastern Canada and northern Greenland and winters along the coasts of northwestern Europe. During northward migration, it stops over in either Iceland or northern Norway. It has been assumed that it does the same during southward migration. Using ratios of stable carbon isotopes (δ ¹³ C) in whole blood, blood cells, and plasma, we investigated evidence for a stopover in Iceland en route from the breeding grounds to the Dutch Wadden Sea. With the expected diet (shellfish) and stopover duration at Iceland (12-15 days, maximum 17 days) and the turnover rates of blood cells (15.1 days) and plasma (6.0 days), Red Knots that stopped in Iceland should arrive with a blood (cell) δ ¹³ C midway between a tundra (-24.7[per thousand]) and a marine value (-14.0[per thousand]) and a plasma δ¹³ C approaching the marine value (-15.3[per thousand]). However, many adults arriving at the Wadden Sea had δ¹³ C ratios in blood (cells) and plasma below these levels, and some arrived with clear tundra signals in blood cells, suggesting that they skipped Iceland during southward migration. Surprisingly, available data suggest this also to be true for juveniles during their first southward migration. The δ ¹³ C signature of second-year birds confirmed that they oversummered in the Wadden Sea. Our findings contradict the largely untested idea that juvenile shorebirds make more stopovers than adults as well as the idea that the migration between the Nearctic and Europe is necessarily a two-leg process.

Longer guts and higher food quality increase energy intake in migratory swans

1.  Within the broad field of optimal foraging, it is increasingly acknowledged that animals often face digestive constraints rather than constraints on rates of food collection. This therefore calls for a formalization of how animals could optimize food absorption rates.

2.  Here we generate predictions from a simple graphical optimal digestion model for foragers that aim to maximize their (true) metabolizable food intake over total time (i.e. including nonforaging bouts) under a digestive constraint.

3.  The model predicts that such foragers should maintain a constant food retention time, even if gut length or food quality changes. For phenotypically flexible foragers, which are able to change the size of their digestive machinery, this means that an increase in gut length should go hand in hand with an increase in gross intake rate. It also means that better quality food should be digested more efficiently.

4.  These latter two predictions are tested in a large avian long-distance migrant, the Bewick's swan (Cygnus columbianus bewickii), feeding on grasslands in its Dutch wintering quarters.

5.  Throughout winter, free-ranging Bewick's swans, growing a longer gut and experiencing improved food quality, increased their gross intake rate (i.e. bite rate) and showed a higher digestive efficiency. These responses were in accordance with the model and suggest maintenance of a constant food retention time.

6.  These changes doubled the birds’ absorption rate. Had only food quality changed (and not gut length), then absorption rate would have increased by only 67%; absorption rate would have increased by only 17% had only gut length changed (and not food quality).

7.  The prediction that gross intake rate should go up with gut length parallels the mechanism included in some proximate models of foraging that feeding motivation scales inversely to gut fullness. We plea for a tighter integration between ultimate and proximate foraging models.

Small home ranges and high site fidelity in red knots (Calidris c. canutus) wintering on the Banc d’Arguin, Mauritania

Using automated and manual radio-telemetry and resightings of individual colour-ringed birds, we assessed the daily use of space of red knots Calidris canutus canutus at a tropical wintering area along the Sahara coast, the Banc d Arguin in Mauritania. Confirming earlier suggestions, we found that birds were very faithful to their roosts and that the daily foraging range was small; in the course of several winter months birds used an area of only 2 16 km2 of intertidal area. We found no differences between their movements in daylight and at night. Additionally, individuals seem to return to exactly the same locations in subsequent winters. This pattern is very different from red knots wintering in the temperate Wadden Sea. Here, they readily change roost sites and easily cover areas of about 800 km2 in the course of weeks but, just as in Mauritania, no differences between day and night are apparent. In northern Patagonia and north-western Australia, red knots have range sizes closer to those on the Banc d Arguin, but here they do show differences in space use between day and night. Ecological explanations for these contrasting patterns require further comparative data based on in-depth studies on the predictability of the food base and the presence of diurnal and nocturnal predators.

Association between food marketing exposure and adolescents' food choices and eating behaviors

The present study examined associations between food marketing exposure and adolescents’ food choices and reported consumption of energy-dense and nutrient-poor (EDNP) foods. A cross-sectional survey of 12,188 Australian secondary students aged 12–17 years was conducted, using a web-based self-report questionnaire. Measures included students’ level of exposure to commercial television and non-broadcast types of food marketing, whether they had tried a new product or requested a product they had seen advertised, and their reported consumption of fast food, sugary drinks and sweet and salty snacks. Results indicated greater exposure to commercial television, print/transport/school food marketing and digital food marketing were all independently associated with students’ food choices. High commercial television viewers (>2 h/day) were more likely to report higher consumption of EDNP foods (ORs ranged from 1.31 for fast food to 1.91 for sweet snacks). Some associations between digital food marketing exposure and students’ eating behaviors were found; however, print/transport/school food marketing was only related to sweet snack consumption. These study results suggest that cumulative exposure to television food advertising and other food marketing sources are positively linked to adolescents’ food choices and eating behaviors. Policy changes to restrict food marketing to young people should include both television and non-broadcast media.

Food references and marketing in popular magazines for children and adolescents in New Zealand. A content analysis

Food marketing is recognized as an important factor influencing children's food preferences and consumption. The purpose of this study was to examine the nature and extent of unhealthy food marketing and non-branded food references in magazines targeted at and popular among children and adolescents 10–17 years in New Zealand. A content analysis was conducted of all food references (branded and non-branded) found in the five magazines with the highest readership among 10–17 year olds, and the three magazines (of which two were already included among the five most popular magazines) targeted to 10–17 year olds. For each of the six magazines one issue per month (n = 72 issues in total) over a one-year period (December 2012–January 2014) was included. All foods referenced were classified into healthy/unhealthy according to the food-based Ministry of Health classification system. Branded food references (30% of total) were more frequent for unhealthy (43%) compared to healthy (25%) foods. Magazines specifically targeted to children and adolescents contained a significantly higher proportion of unhealthy branded food references (72%, n = 51/71) compared to the most popular magazines among children and adolescents (42%, n = 133/317), of which most were targeted to women. ‘Snack items’ such as chocolates and ice creams were marketed most frequently (n = 104; 36%), while ‘vegetables and fruits’ were marketed the least frequently (n = 9; 3%). Direct advertisements accounted for 27% of branded food references and 25% of those featured health or nutrition claims. Both branded and non-branded food references were common within magazines targeted at and popular among children and adolescents, and skewed toward unhealthy foods. This raises concerns about the effectiveness of self-regulation in marketing and emphasizes that government regulations are needed in order to curb children's current potential high exposures to unhealthy food marketing. In addition, magazine editors could take socially responsible editorial positions in regard to healthy eating.