Summary
The consumption frequency and portion size of discretionary snacks are thought to contribute to a greater food intake and risk of overweight or obesity in the developed world but evidence ...from epidemiological studies is inconclusive. To investigate this, we systematically evaluated evidence on the effects of discretionary snack consumption on weight status, energy intake, and diet quality. Articles involving discretionary snacks reported against the outcome measures of any primary, peer‐reviewed study using human participants from free‐living conditions for all age groups were included. A total of 14,780 titles were identified and 40 eligible publications were identified. Three key outcomes were reported: weight status (n = 35), energy intake (n = 11), and diet quality (n = 3). Increased discretionary snack consumption may contribute modestly to energy intake, however, there is a lack of consistent associations with increased weight/BMI. Although cross‐sectional analyses offered conflicting findings, longitudinal studies in adults showed a consistent positive relationship between discretionary snack intake and increasing weight or body mass index. Given that experimental findings suggest reducing the size of discretionary snacks could lead to decreased consumption and subsequent energy intake, food policy makers and manufacturers may find it valuable to consider altering the portion and/or packaging size of discretionary snacks.
Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH4. In September 2014 and July 2015, octocopters were used to collect air samples in Tedlar bags ...from different heights above and below the well‐defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700 m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH4, but no distinct shift in δ13C was observed compared to the air below. Back trajectories indicate that lofted CH4 emissions from Southern Hemisphere Africa have bulk δ13CCH4 signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region.
Key Points
Methane mole fraction and δ13C have been measured from samples collected by UASs on Ascension Island over two campaigns
CH4 mole fraction increases above the TWI, but isotopes have no consistent signal indicating input from Africa is close to background
The campaigns illustrate the usefulness of UAS sampling and Ascension's value for atmospheric measurement in an understudied region
Background: Dietary behaviours of adolescence are concerning, and this may impact long-term well-being. Aim: This study examined the socio-ecological determinants of dietary behaviours in a national ...prospective cohort study of English adolescents. Methods: Latent class analysis was used to identify the typologies of eight dietary behaviours: fruit, vegetable, breakfast, sugar-sweetened beverages, artificial-sweetened beverages, fast-food, bread, and milk from 7402 adolescents aged 13–15 years (mean 13.8 ± 0.45 years) (50.3% female and 71.3% white ethnicity) participating in the U.K. Millennium Cohort Study (sixth survey). Multinomial logistic regression and path analysis predicted associations between personal characteristics, individual, influential others, social environment and physical environment determinants and three distinct diet typologies: (1) healthy, (2) less-healthy and (3) mixed, (reference category = mixed). Results: Within Path analysis, the magnitudes of coefficients were small to moderate suggesting a relatively weak relationship between the variables. Model 1 reported adolescents within the less-healthy compared to mixed typology had lower levels of physical activity (β = 0.074, 95% CI = −0.115, −0.033), and have siblings (β = 0.246, 95% CI = 0.105, 0.387). Model 2 reported adolescents within the healthy compared to mixed typology had lower screen time (β = 0.104, 95% CI = 0.067, 0.141), and lower social media usage (β = 0.035, 95% CI = 0.024, 0.046). Conclusion: This study highlights the importance of considering multiple dietary determinants. These findings are likely to be useful in supporting the development of multi-faceted interventions. They emphasise the need to move away from investigating silo behaviours on individual diet components and a step towards more systems thinking to improve adolescent eating behaviours.
Objective: To evaluate the effect of a high‐protein diet on anthropometry, body composition, subjective appetite, and mood sensations in overweight and obese children attending a residential ...weight‐loss camp.
Research Methods and Procedures: Children (120; BMI, 33.1 ± 5.5 kg/m2; age, 14.2 ± 1.9 years) were randomly assigned to either a standard or high‐protein diet group (15% vs. 22.5% protein, respectively). All children were assessed at baseline and at the end of the camp for anthropometry, body composition, blood pressure, biochemical variables (n = 27), and subjective appetite and mood sensations (n = 50).
Results: Attendance at the weight‐loss camp resulted in significant improvements in most measures. Campers lost 5.5 ± 2.9 kg in body weight (p < 0.001) and 3.8 ± 5.4 kg in fat mass (p < 0.001) and reduced their BMI standard deviation score by 0.27 ± 0.1 (p < 0.001) and their waist circumference by 6.6 ± 2.8 cm (p < 0.001). Subjective sensations of hunger increased significantly over the camp duration, but no other changes in appetite or mood were observed. There were no significant differences between the two diets on any physical or subjective measures.
Discussion: Weight‐loss camps are effective in assisting children to lose weight and improve on a range of health outcomes, independently of the protein content of the diet. The implications of an increase in hunger associated with weight loss needs to be considered. Further work is warranted to investigate whether higher levels of dietary protein are feasible or effective in longer‐term weight‐loss interventions of this type.
Background
With an established, yet avoidable, link between dietary intake and poor health, the nutritional habits of adolescents remains a public health concern. Previous studies report an inverse ...relationship between dietary intake and socio‐economic status (SES), although few studies have considered the influence of the SES gradient. The present study compared the nutritional profiles of neighbouring schools with pupils from middle to high economic backgrounds.
Methods
One hundred and ninety pupils from a high SES school (HSESS) and 159 pupils from a middle SES school (MSESS) (aged 11–12 years) completed a 63‐item validated food frequency questionnaire. Pupils rated their diet quality and this was compared with a composite Healthy Eating Index (HEI).
Results
Children attending MSESS consumed significantly higher intakes of energy (P < 0.001), carbohydrate (P = 0.001), fat (P < 0.001) and protein (P = 0.001). As a percentage of energy contribution, pupils in both schools consumed excess saturated fat (HSESS, +5% boys, +4% girls; MSESS, +4% both boys and girls) and sugar (HSESS, +9% boys, +11% girls; MSESS, +10% boys, +11% girls). When HEI was compared with self‐report diet quality, 96% HSESS pupils and 94% MSESS pupils over‐rated the quality of their diet.
Conclusions
The present study identified that, although pupils from MSESS consume a significantly higher intake of energy and macronutrient compared to a nearby HSESS, the percentage of energy contribution of saturated fat and sugar is above government recommendations for pupils from both schools. Additionally, the majority of pupils from both schools substantially over‐rated their diet quality compared to a HEI.
Abstract
Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH
4
. In September 2014 and July 2015, octocopters were used to collect air samples in ...Tedlar bags from different heights above and below the well‐defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700 m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH
4
, but no distinct shift in δ
13
C was observed compared to the air below. Back trajectories indicate that lofted CH
4
emissions from Southern Hemisphere Africa have bulk δ
13
C
CH4
signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region.
Key Points
Methane mole fraction and δ
13
C have been measured from samples collected by UASs on Ascension Island over two campaigns
CH
4
mole fraction increases above the TWI, but isotopes have no consistent signal indicating input from Africa is close to background
The campaigns illustrate the usefulness of UAS sampling and Ascension's value for atmospheric measurement in an understudied region
Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH4. In September 2014 and July 2015, octocopters were used to collect air samples in Tedlar bags ...from different heights above and below the well-defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH4, but no distinct shift in delta13C was observed compared to the air below. Back trajectories indicate that lofted CH4 emissions from Southern Hemisphere Africa have bulk delta13CCH4 signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region.
Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH sub(4). In September 2014 and July 2015, octocopters were used to collect air samples in ...Tedlar bags from different heights above and below the well-defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH sub(4), but no distinct shift in delta super(13)C was observed compared to the air below. Back trajectories indicate that lofted CH sub(4) emissions from Southern Hemisphere Africa have bulk delta super(13)C sub(CH4) signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region. Key Points * Methane mole fraction and delta super(13)C have been measured from samples collected by UASs on Ascension Island over two campaigns * CH sub(4) mole fraction increases above the TWI, but isotopes have no consistent signal indicating input from Africa is close to background * The campaigns illustrate the usefulness of UAS sampling and Ascension's value for atmospheric measurement in an understudied region
Most ecosystems have multiple predator species that not only compete for shared prey, but also pose direct threats to each other. These intraguild interactions are key drivers of carnivore community ...structure, with ecosystem‐wide cascading effects. Yet, behavioral mechanisms for coexistence of multiple carnivore species remain poorly understood. The challenges of studying large, free‐ranging carnivores have resulted in mainly coarse‐scale examination of behavioral strategies without information about all interacting competitors. We overcame some of these challenges by examining the concurrent fine‐scale movement decisions of almost all individuals of four large mammalian carnivore species in a closed terrestrial system. We found that the intensity of intraguild interactions did not follow a simple hierarchical allometric pattern, because spatial and behavioral tactics of subordinate species changed with threat and resource levels across seasons. Lions (Panthera leo) were generally unrestricted and anchored themselves in areas rich in not only their principal prey, but also, during periods of resource limitation (dry season), rich in the main prey for other carnivores. Because of this, the greatest cost (potential intraguild predation) for subordinate carnivores was spatially coupled with the highest potential benefit of resource acquisition (prey‐rich areas), especially in the dry season. Leopard (P. pardus) and cheetah (Acinonyx jubatus) overlapped with the home range of lions but minimized their risk using fine‐scaled avoidance behaviors and restricted resource acquisition tactics. The cost of intraguild competition was most apparent for cheetahs, especially during the wet season, as areas with energetically rewarding large prey (wildebeest) were avoided when they overlapped highly with the activity areas of lions. Contrary to expectation, the smallest species (African wild dog, Lycaon pictus) did not avoid only lions, but also used multiple tactics to minimize encountering all other competitors. Intraguild competition thus forced wild dogs into areas with the lowest resource availability year round. Coexistence of multiple carnivore species has typically been explained by dietary niche separation, but our multi‐scaled movement results suggest that differences in resource acquisition may instead be a consequence of avoiding intraguild competition. We generate a more realistic representation of hierarchical behavioral interactions that may ultimately drive spatially explicit trophic structures of multi‐predator communities.
OBJECTIVE: To evaluate the effect of a high-protein diet on anthropometry, body composition, subjective appetite, and mood sensations in overweight and obese children attending a residential ...weight-loss camp. RESEARCH METHODS AND PROCEDURES: Children (120; BMI, 33.1 ± 5.5 kg/m²; age, 14.2 ± 1.9 years) were randomly assigned to either a standard or high-protein diet group (15% vs. 22.5% protein, respectively). All children were assessed at baseline and at the end of the camp for anthropometry, body composition, blood pressure, biochemical variables (n = 27), and subjective appetite and mood sensations (n = 50). RESULTS: Attendance at the weight-loss camp resulted in significant improvements in most measures. Campers lost 5.5 ± 2.9 kg in body weight (p < 0.001) and 3.8 ± 5.4 kg in fat mass (p < 0.001) and reduced their BMI standard deviation score by 0.27 ± 0.1 (p < 0.001) and their waist circumference by 6.6 ± 2.8 cm (p < 0.001). Subjective sensations of hunger increased significantly over the camp duration, but no other changes in appetite or mood were observed. There were no significant differences between the two diets on any physical or subjective measures. DISCUSSION: Weight-loss camps are effective in assisting children to lose weight and improve on a range of health outcomes, independently of the protein content of the diet. The implications of an increase in hunger associated with weight loss needs to be considered. Further work is warranted to investigate whether higher levels of dietary protein are feasible or effective in longer-term weight-loss interventions of this type.
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