The primary aim of this study was to examine the association between snack nutritional quality, overall diet quality and adiposity among Australian adolescents. The secondary aim was to assess the distribution of discretionary foods (i.e. energy-dense and nutrient-poor foods and beverages) and intakes from the five food groups at different levels of snack nutritional quality. Dietary data collected from nationally representative adolescents (12–18 years old) during a 24-h dietary recall in the National Nutrition and Physical Activity Survey were analysed (n 784). Snacks were defined based on participant-identified eating occasions. Snack nutritional quality was assessed using the Nutrient Profiling Scoring Criterion (NPSC), whereas diet quality was evaluated using the Dietary Guideline Index for Children and Adolescents. Adiposity was assessed through BMI Z-score waist circumference and waist:height ratio (WHtR). Higher nutritional quality of snacks, as assessed by the NPSC, has been associated with higher diet quality among both boys and girls (P < 0·001). However, there is no association between snacks nutritional quality with BMI Z-score, waist circumference and WHtR. Among both boys and girls, the consumption of fruits, vegetables and legumes/beans at snacks increased with improvement in snack nutritional quality. Conversely, the consumption of discretionary foods at snack decreased with improvement in snack nutritional quality. In conclusion, improved snack quality was associated with better diet quality in adolescents. However, there was no association between snack nutritional quality and adiposity. Future, snack nutrition quality indices should consider optimum snack characteristics related with adiposity and diet quality.

Snacking is a common eating behaviour among adolescents accounting for more than a quarter of their total energy intake but the relationship between snacks and overall diet quality remains unclear(1). Hence, the aim of this study was to examine characteristics of snacks among Australian adolescents (12-18 years) according to their level of diet quality. This secondary analysis uses one day of 24-hour dietary recall data from the 2011 - 2012 National Nutrition and Physical Activity Survey (n = 935). Snacks were defined based on participant-identified eating occasions(2). The Dietary Guideline Index for Children and Adolescents (DGI-CA) was used to assessed adherence to the Australian Dietary Guidelines(3), with the highest tertile of the DGI-CA score indicating high adherence. The means (95% confidence intervals [CI]) for daily snack frequency and snack energy density (ED; kJ/g) were estimated for boys and girls, using linear regression, adjusted for age, area-level disadvantage, and energy misreporting. The differences in means and proportions across tertiles of DGI-CA scores were tested by using F- and Chi square-tests, respectively. The results show no significant differences in the mean frequency of snacks across tertiles of DGI-CA scores in either boys (lowest tertile mean = 2.2, 95% CI [2.0, 2.4] snacks/day, highest tertile = 2.1 [1.9, 2.3]) or girls (lowest tertile = 1.9 [1.7, 2.1] snacks/day, highest tertile = 2.2 [1.9, 2.4]). The mean ED of snacks decreased as DGI-CA scores increased in both boys (lowest tertile = 8.42, 95% CI [7.1, 10] kJ/g, highest tertile = 6.32 [5.4, 7.4] kJ/g) and girls (lowest tertile = 8.99 [7.8, 10.3] kJ/g, highest tertile = 5.92 [5.1, 6.9] kJ/g). As DGI-CA scores increased, the proportion of both boys and girls consuming discretionary foods at snacks (such as soft drinks) decreased, while foods from the five food groups (such as apples) increased (p-values < 0.05). In conclusion, snack ED, but not frequency, and the types of foods consumed by adolescents at snacks varied by a level of diet quality. Snack ED decreased with increasing diet quality and adolescents with higher diet quality had higher intakes of foods from the five food groups and lower intakes of discretionary foods at snacks. Encouraging the consumption of lower-ED foods from the five food groups at snacks presents an opportunity to enhance adolescent diet quality. Future studies should explore snack-specific strategies to improve overall diet quality of adolescents.

The prevalence of overweight and obesity in children and adults has increased worldwide. A strong environmental factor contributing to the obesity epidemic is food portion size (PS). This review evaluates the current evidence linking food PS to obesity, examines the effects of PS on energy intake (EI), and discusses the drivers of food PS selection. The leading causes of the rise in PS include globalisation, intensive farming methods, the impact of World War II, due to shortage of staple foods, and the notion of ‘waste not, want not’. Large PS of energy-dense foods may stimulate overconsumption, leading to high EI levels. However, the studies have not shown a cause-and-effect relationship, due to confounding factors. Important mechanisms explaining the attractiveness of larger PS leading to higher EI levels are value for money, portion distortion, labels on food packaging, and tableware. Consumers depend on external rather than internal PS cues to guide consumption, irrespective of satiety levels. Further research is recommended on food consumption patterns to inform policymakers and provide information and insights about changes in diet.

Food-based dietary guidelines have been the basis of public health recommendations for over half a century, but more recently, there has been a trend to classify the health properties of food not by its nutrient composition, but by the degree to which it has been processed. This concept has been supported by many association studies, narrative reviews and the findings from one randomised controlled feeding trial, which demonstrated the sustained effect of ultra-processed diets on increasing both energy intake and body weight. This has led to widespread speculation as to specific features of ultra-processed foods that promote increased energy intakes. Rising interest in the ultra-processed topic has led to proposals to include guidance and restrictions on the consumption of processed foods in national dietary guidelines, with some countries encouraging consumers to avoid highly processed foods completely, and only choose minimally processed foods. However, there remains a lack of consensus on the role of processed foods in human health when faced with the challenges of securing the food supply for a growing global population, that is, healthy, affordable and sustainable. There has also been criticism of the subjective nature of definitions used to differentiate foods by their degree of processing, and there is currently a lack of empirical data to support a clear mechanism by which highly processed foods promote greater energy intakes. Recommendations to avoid all highly processed foods are potentially harmful if they remove affordable sources of nutrients and will be impractical for most when an estimated two-thirds of current energy purchased are from processed or ultra-processed foods. The current review highlights some considerations when interpreting the dietary association studies that link processed food intake to health and offers a critique on some of the mechanisms proposed to explain the link between ultra-processed food and poor health. Recent research suggests a combination of higher energy density and faster meal eating rates are likely to influence meal size and energy intakes from processed foods and offers new perspectives on how to manage this in the future. In going beyond the ultra-processed debate, the aim is to summarise some important considerations when interpreting existing data and identify the important gaps for future research on the role of processed food in health.

‘Dietary variety’ has been identified as a factor associated with food intake. Whilst this relationship may have longer-term benefits for body weight management when eating low-energy, nutrient-dense foods, it may increase the risk of overconsumption (and body adiposity) when foods are high energy density. This study sought to further explore pathways underpinning the relationship between dietary variety and body weight, by considering energy density as a moderating factor and portion size as a mediating factor in this relationship. Using prospective data from the UK Biobank, dietary variety scores (DVS), cumulative portion size and energy density were derived from 24-h dietary recall questionnaires at baseline and follow-up. BMI, whole-body fat percentage and fat-free mass were included as outcomes. Contrary to predictions, linear multiple regression models found some evidence of a negative, direct association between DVS and body weight outcomes at baseline (b = –0·13). Though dietary variety was significantly associated with larger portions across time points (b = 41·86–82·64), a moderated mediation effect was not supported at baseline or follow-up (Index ≤ 0·035). Taken together, these findings provide population-level evidence to support a positive association between variety and food intake, which in turn has potential implications for body weight management, both in terms of moderating food intake and benefitting diet quality.

The present study examined the association of contextual factors (social and food preparation location) with the energy density of meals and snacks consumed in a sample of young Australian adults (18–30 years old) identified using wearable camera technology. Over three consecutive days, a subsample of young adults wore a wearable camera that captured images in 30 s intervals. Eating episodes from 133 participants were annotated for preparation location and social context (covering social interaction and screen use). Over the same period, participants completed daily 24 h recalls. The nutritional composition of meals and snacks was calculated by matching the items identified in the camera to the 24 h recall using time and date stamps. Self-reported data (weight and height) was used to calculate body mass index and (residential postcode) to assign socio-economic status. The association of context and demographic factors with energy density was determined using a mixed linear regression model employing the bootstrap method with bias-corrected and accelerated. In total, 1817 eating episodes were included in the analysis (n 8 preparation unclear and n 15 food components could not be identified excluded). Food prepared within the home was 1⋅1 kJ/g less energy-dense than other preparation locations. Lunches (CI −1⋅7 to −0⋅3) and dinners (CI −1⋅6 to −0⋅5) were both 1⋅0 kJ/g lower in energy density than breakfasts. Snacks were 3⋅5 kJ/g (CI 2⋅8–4⋅1) more energy-dense than breakfasts. Food prepared outside the home and food consumption during snacking appear to be adversely contributing to energy-dense food intake.

The impact of Sacculina carcini infection on the nutritional status of the shore crab Carcinus maenas was investigated in the western Dutch Wadden Sea for a period of 20 months. About 3.3% of the population was sacculinized, i.e. externally infected with S. carcini and only 0.7% presented scars of previous infection. The results of mixed linear models showed that sacculinized and non-sacculinized crabs had similar morphometric condition, while the energy density of parasitized crabs (externa excluded) was significantly reduced by about 4.3% overall, and by up to 5.8% in crabs under 40 mm carapace width. However, when Sacculina externa was included in the energy determinations, the difference in energy density decreased to 1.2%, while total energy content of the pair infected crab-parasite including externa was 30.8% higher than non-sacculinized crabs of similar size. The total energy content of ovigerous females (eggs included) was even higher, near doubling the energy of similar-sized crabs. The same way, total energy content of Sacculina externa was about 4 times lower than total energy of egg mass. The results suggest that the rhizocephalan parasite is efficient in consuming the energy that the host may allocate for growth and maintenance, but require future studies to disentangle the impact of the degree of internal infection and the implications for the dynamics of the population.

Higher consumption of ‘ultra-processed’ (UP) foods has been linked to adverse health outcomes. The present paper aims to characterise percentage energy from UP foods by participant socio-economic status (SES), diet quality, self-reported food expenditure and energy-adjusted diet cost. Participants in the population-based Seattle Obesity Study III (n 755) conducted in WA in 2016–2017 completed socio-demographic and food expenditure surveys and the FFQ. Education and residential property values were measures of SES. Retail prices of FFQ component foods (n 378) were used to estimate individual-level diet cost. Healthy Eating Index (HEI-2015) and Nutrient Rich Food Index 9.3 (NRF9.3) were measures of diet quality. UP foods were identified following NOVA classification. Multivariable linear regressions were used to test associations between UP foods energy, socio-demographics, two estimates of food spending and diet quality measures. Higher percentage energy from UP foods was associated with higher energy density, lower HEI-2015 and NRF9.3 scores. The bottom decile of diet cost ($216·4/month) was associated with 67·5 % energy from UP foods; the top decile ($369·9/month) was associated with only 48·7 % energy from UP foods. Percentage energy from UP foods was inversely linked to lower food expenditures and diet cost. In multivariate analysis, percentage energy from UP foods was predicted by lower food expenditures, diet cost and education, adjusting for covariates. Percentage energy from UP foods was linked to lower food spending and lower SES. Efforts to reduce UP foods consumption, an increasingly common policy measure, need to take affordability, food expenditures and diet costs into account.

This trial compared weight loss outcomes over 14 weeks in women showing low- or high-satiety responsiveness (low- or high-satiety phenotype (LSP, HSP)) measured by a standardised protocol. Food preferences and energy intake (EI) after low and high energy-density (LED, HED) meals were also assessed. Ninety-six women (n 52 analysed; 41·24 (SD 12·54) years; 34·02 (sd 3·58) kg/m2) engaged in one of two weight loss programmes underwent LED and HED laboratory test days during weeks 3 and 12. Preferences for LED and HED food (Leeds Food Preference Questionnaire) and ad libitum evening meal and snack EI were assessed in response to equienergetic LED and HED breakfasts and lunches. Weekly questionnaires assessed control over eating and ease of adherence to the programme. Satiety quotients based on subjective fullness ratings post LED and HED breakfasts determined LSP (n 26) and HSP (n 26) by tertile splits. Results showed that the LSP lost less weight and had smaller reductions in waist circumference compared with HSP. The LSP showed greater preferences for HED foods, and under HED conditions, consumed more snacks (kJ) compared with HSP. Snack EI did not differ under LED conditions. LSP reported less control over eating and reported more difficulty with programme adherence. In conclusion, low-satiety responsiveness is detrimental for weight loss. LED meals can improve self-regulation of EI in the LSP, which may be beneficial for longer-term weight control.

This study examined (1) the association of dietary energy density from solid (EDS) and solid plus liquids (EDSL) with adiposity and cardiometabolic risk factors (CRF) in children with overweight and obesity, (2) the effect of under-reporting on the mentioned associations and (3) whether the association between ED and body composition and CRF is influenced by levels of physical activity. In a cross-sectional design, 208 overweight and obese children (8–12-year-old; 111 boys) completed two non-consecutive 24 h recalls. ED was calculated using two different approaches: EDS and EDSL. Under-reporters were determined with the Goldberg method. Body composition, anthropometry and fasting blood sample measurements were performed. Moderate to vigorous physical activity (MVPA) was registered with accelerometers (7-d-register). Linear regressions were performed to evaluate the association of ED with the previously mentioned variables. Neither EDS nor EDSL were associated with body composition or CRF. However, when under-reporters were excluded, EDS was positively associated with BMI (P=0·019), body fat percentage (P=0·005), abdominal fat (P=0·008) and fat mass index (P=0·018), while EDSL was positively associated with body fat percentage (P=0·008) and fat mass index (P=0·026). When stratifying the group according to physical activity recommendations, the aforementioned associations were only maintained for non-compliers. Cluster analysis showed that the low-ED and high-MVPA group presented the healthiest profile for all adiposity and CRF. These findings could partly explain inconsistencies in literature, as we found that different ED calculations entail distinct results. Physical activity levels and excluding under-reporters greatly influence the associations between ED and adiposity in children with overweight and obesity.

The paper presents the results of a study on propagation and focusing of high-intensity pulsed ion beams, produced by a self-magnetically insulated diode of semi-cylindrical geometry at the TEMP-6 accelerator (120 ns, 200–250 kV). We examined the space-charge neutralization of the beam, the energy density in the focus, the divergence of the beam, and its shot-to-shot displacement in the focal plane. It is found that the concentration of low-energy electrons in the beam is 1.3–1.5 times higher than the concentration of ions. We observed additional ion focusing by its own space charge. With an increase in the density of the net negative (electrons and ions) charge of the beam from 3.6 to 9 µC/cm2, the total divergence (the sum of the beam divergence in the vertical and horizontal planes) decreases from 11.4 to 4.5°. It leads to an increase in the energy density in the focus from 4 up to 10–12 J/cm2. To increase the electrons concentration in the beam, a metal grid installed in the ion beam transport region was used.

The Nestlé Nutritional Profiling System (NNPS) has been developed to guide food and beverage reformulation. The WHO published guidelines to develop and validate nutrient profiling systems. The objective was to conduct validation tests of the NNPS following principles of the WHO guidelines. French (Individual and National Survey on food Consumption 2006–2007) and the USA (National Health and Nutrition Examination Surveys 2011–2012) nationally representative dietary surveys were used. NNPS outcomes (PASS, FAIL, out-of-scope) of foods were compared with the validated UK Ofcom nutrient profiling system outcomes. Contributions of NNPS outcomes to energy intakes were compared between diets nutritional quality classes defined by two methods: based on a food-based quality indicator (Programme National Nutrition Santé Guideline Score in France, Healthy Eating Index 2010 in the USA) or on a combination of three nutrient-based indicators (mean adequacy ratio, mean excess ratio and energy density). In both countries, food items with a NNPS FAIL outcome had a lower nutritional quality according to the UK Ofcom, with an overall agreement between the two systems of 75·7 % in France and 68·8 % in the USA. In both countries, a high (respectively, low) contribution of NNPS PASS (respectively, NNPS FAIL) was positively associated with diet healthiness. Absolute associations were stronger between the contribution of NNPS FAIL products and measures of diet healthiness. Foods and beverages reaching NNPS standards appeared to have a higher nutritional quality and would be more likely to contribute to healthier diets, mainly linked to a reduction of nutrients to limit.

Offering large portions of high-energy-dense (HED) foods increases overall intake in children and adults. This is known as the portion size effect (PSE). It is robust, reliable and enduring. Over time, the PSE may facilitate overeating and ultimately positive energy balance. Therefore, it is important to understand what drives the PSE and what might be done to counter the effects of an environment promoting large portions, especially in children. Explanations for the PSE are many and diverse, ranging from consumer error in estimating portion size to simple heuristics such as cleaning the plate or eating in accordance with consumption norms. However, individual characteristics and hedonic processes influence the PSE, suggesting a more complex explanation than error or heuristics. Here PSE studies are reviewed to identify interventions that can be used to downsize portions of HED foods, with a focus on children who are still learning about social norms for portion size. Although the scientific evidence for the PSE is robust, there is still a need for creative downsizing solutions to facilitate portion control as children and adolescents establish their eating habits.