Benchmarking online food delivery applications against menu labelling laws: a cross-sectional observational analysis.

OBJECTIVE: It is unknown how well menu labelling schemes that enforce the display of kilojoule (kJ) labelling at point-of-sale have been implemented on online food delivery (OFD) services in Australia. This study aimed to examine the prevalence of kJ labelling on the online menus of large food outlets with more than twenty locations in the state or fifty locations nationally. A secondary aim was to evaluate the nutritional quality of menu items on OFD from mid-sized outlets that have fewer locations than what is specified in the current scheme. DESIGN: Cross-sectional analysis. Prevalence of kJ labelling by large food outlets on OFD from August to September 2022 was examined. Proportion of discretionary ('junk food') items on menus from mid-sized outlets was assessed. SETTING: Forty-three unique large food outlets on company (e.g. MyMacca's) and third party OFD (Uber Eats, Menulog, Deliveroo) within Sydney, Australia. Ninety-two mid-sized food outlets were analysed. PARTICIPANTS: N/A. RESULTS: On company OFD apps, 35 % (7/23) had complete kJ labelling for each menu item. In comparison, only 4·8 % (2/42), 5·3 % (2/38) and 3·6 % (1/28) of large outlets on Uber Eats, Menulog and Deliveroo had complete kJ labelling at all locations, respectively. Over three-quarters, 76·3 % (345/452) of menu items from mid-sized outlets were classified as discretionary. CONCLUSIONS: Kilojoule labelling was absent or incomplete on a high proportion of online menus. Mid-sized outlets have abundant discretionary choices and yet escape criteria for mandatory menu labelling laws. Our findings show the need to further monitor the implementation of nutrition policies on OFD.

Isolation, purification, and structural characterization of polysaccharides from Codonopsis pilosula and its therapeutic effects on non-alcoholic fatty liver disease in vitro and in vivo.

Codonopsis pilosula is a famous edible and medicinal plants, in which polysaccharides are recognized as one of the important active ingredients. A neutral polysaccharide (CPP-1) was purified from C. pilosula. The structure was characterized by HPSEC-MALLS-RID, UV, FT-IR, GC-MS, methylation analysis, and NMR. The results showed that CPP-1 was a homogeneous pure polysaccharide, mainly containing fructose and glucose, and a small amount of arabinose. Methylation analysis showed that CPP-1 composed of →1)-Fruf-(2→, Fruf-(1→ and Glcp-(1→ residues. Combined the NMR results the structure of CPP-1 was confirmed as α-D-Glcp-(1 â†’ [2)-ß-D-Fruf-(1 â†’ 2)-ß-D-Fruf-(1]26 â†’ 2)-ß-D-Fruf with the molecular weight of 4.890 × 103 Da. The model of AML12 hepatocyte fat damage was established in vitro. The results showed that CPP-1 could increase the activity of SOD and CAT antioxidant enzymes and reduce the content of MDA, thus protecting cells from oxidative damage. Subsequently, the liver protective effect of CPP-1 was studied in the mouse model of nonalcoholic fatty liver disease (NAFLD) induced by the high-fat diet. The results showed that CPP-1 significantly reduced the body weight, liver index, and body fat index of NAFLD mice, and significantly improved liver function. Therefore, CPP-1 should be a potential candidate for the treatment of NAFLD.

Use of online food retail platforms throughout the COVID-19 pandemic and associated diet-related chronic disease risk factors: A systematic review of emerging evidence.

Food accessibility was considerably impacted by restrictions during the coronavirus disease 2019 (COVID-19) pandemic, leading to growth in the online food retail sector, which offered contact-free delivery. This systematic review aimed to assess the change in use of online food retail platforms during COVID-19. The secondary aim was to identify diet-related chronic disease risk factors including dietary intake, eating behaviors, and/or weight status associated with the use of online food retail platforms during the pandemic. The review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42022320498) and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Nine electronic databases were searched between January 2020 and October 2023. Studies that reported the frequency or change in use of online groceries, meal delivery applications, and/or meal-kit delivery services before and during the pandemic were included. A total of 53 studies were identified, including 46 cross-sectional studies, 4 qualitative studies, 2 longitudinal cohort studies, and 1 mixed-methods study. Overall, 96% (43/45) of outcomes showed an increase in the use of online groceries during COVID-19, while 55% (22/40) of outcomes showed a decrease in meal delivery applications. Eight of nine outcomes associated the use of online food retail with weight gain and emotional eating. Further research is needed to investigate the links between online food retail and obesity.

Optimization of Three Extraction Methods and Their Effect on the Structure and Antioxidant Activity of Polysaccharides in Dendrobium huoshanense.

Dendrobium huoshanense is a famous edible and medicinal herb, and polysaccharides are the main bioactive component in it. In this study, response surface methodology (RSM) combined with a Box-Behnken design (BBD) was used to optimize the enzyme-assisted extraction (EAE), ultrasound-microwave-assisted extraction (UMAE), and hot water extraction (HWE) conditions and obtain the polysaccharides named DHP-E, DHP-UM, and DHP-H. The effects of different extraction methods on the physicochemical properties, structure characteristics, and bioactivity of polysaccharides were compared. The differential thermogravimetric curves indicated that DHP-E showed a broader temperature range during thermal degradation compared with DHP-UM and DHP-H. The SEM results showed that DHP-E displayed an irregular granular structure, but DHP-UM and DHP-H were sponge-like. The results of absolute molecular weight indicated that polysaccharides with higher molecular weight detected in DHP-H and DHP-UM did not appear in DHP-E due to enzymatic degradation. The monosaccharide composition showed that DHPs were all composed of Man, Glc, and Gal but with different proportions. Finally, the glycosidic bond types, which have a significant effect on bioactivity, were decoded with methylation analysis. The results showed that DHPs contained four glycosidic bond types, including Glcp-(1→, →4)-Manp-(1→, →4)-Glcp-(1→, and →4,6)-Manp-(1→ with different ratios. Furthermore, DHP-E exhibited better DPPH and ABTS radical scavenging activities. These findings could provide scientific foundations for selecting appropriate extraction methods to obtain desired bioactivities for applications in the pharmaceutical and functional food industries.

Using Mobile Ecological Momentary Assessment to Understand Consumption and Context Around Online Food Delivery Use: Pilot Feasibility and Acceptability Study.

BACKGROUND: Mobile ecological momentary assessment (EMA) is a powerful tool for collecting real-time and contextual data from individuals. As our reliance on online technologies to increase convenience accelerates, the way we access food is changing. Online food delivery (OFD) services may further encourage unhealthy food consumption habits, given the high availability of energy-dense, nutrient-poor foods. We used EMA to understand the real-time effects of OFD on individuals' food choices and consumption behaviors. OBJECTIVE: The primary aims of this pilot study were to assess the feasibility and acceptability of using EMA in young users of OFD and compare 2 different EMA sampling methods. The secondary aims were to gather data on OFD events and their context and examine any correlations between demographics, lifestyle chronic disease risk factors, and OFD use. METHODS: This study used EMA methods via a mobile app (mEMASense, ilumivu Inc). Existing users of OFD services aged 16 to 35 years in Australia who had access to a smartphone were recruited. Participants were randomly assigned to 1 of 2 groups: signal-contingent or event-contingent. The signal-contingent group was monitored over 3 days between 7 AM and 10 PM. They received 5 prompts each day to complete EMA surveys via the smartphone app. In contrast, the event-contingent group was monitored over 7 days and was asked to self-report any instance of OFD. RESULTS: A total of 102 participants were analyzed, with 53 participants in the signal-contingent group and 49 participants in the event-contingent group. Compliance rates, indicating the feasibility of signal-contingent and event-contingent protocols, were similar at 72.5% (574/792) and 73.2% (251/343), respectively. Feedback from the participants suggested that the EMA app was not easy to use, which affected their acceptability of the study. Participants in the event-contingent group were 3.53 (95% CI 1.52-8.17) times more likely to have had an OFD event captured during the study. Pizza (23/124, 18.5%) and fried chicken (18/124, 14.5%) comprised a bulk of the 124 OFD orders captured. Most orders were placed at home (98/124, 79%) for 1 person (68/124, 54.8%). Age (incidence rate ratio 0.95, 95% CI 0.91-0.99; P=.03) and dependents (incidence rate ratio 2.01, 95% CI 1.16-3.49; P=.01) were significantly associated with the number of OFD events in a week after adjusting for gender, socioeconomic status, diet quality score, and perceived stress levels. CONCLUSIONS: This pilot study showed that EMA using an event-contingent sampling approach may be a better method to capture OFD events and context than signal-contingent sampling. The compliance rates showed that both sampling methods were feasible and acceptable. Although the findings from this study have gathered some insight on the consumption and context of OFD in young people, further studies are required to develop targeted interventions.

An analysis of current obesity strategies for adolescents in NSW against best practice recommendations: Implications for researchers, policymakers and practitioners.

ISSUE ADDRESSED: Obesity is a significant health challenge facing adolescents. There is a critical need for government action to support all adolescents to improve risk factors for obesity. This study critically appraised initiatives, guidelines and policies (termed "strategies") from local health districts (LHDs), speciality health networks and Primary Health Networks (PHNs) across New South Wales (NSW), relevant to the prevention and management of obesity amongst adolescents and compare these to best practice recommendations. METHODS: We critically appraised strategies against best practice recommendations that included support, access, responsiveness to needs, supportive environment, monitoring and evaluation and health equity. Strategies were collected by systematically searching websites of 15 LHDs, one speciality health network and 10 PHNs. RESULTS: There was evidence of strategies regarding adolescent obesity prevention and management across all best practice recommendations. There was limited evidence of adolescent consumer participation, digital strategies for health services and online health information. There were minimal targeted public or school-based education campaigns and interventions on physical activity or nutrition. Place-based approaches such as sports and recreation facilities were not included in policies regarding the sale of healthy food and drinks. Evaluation evidence across all strategies was minimal. CONCLUSIONS: Numerous strategies are being implemented across NSW to address adolescent obesity. Despite this, the alignment of strategies with best practice recommendations is poor and evidence of progress in tackling adolescent obesity remains unclear. SO WHAT?: Opportunities to generate and translate best practice evidence within government strategies for obesity must be prioritised with embedded measurement and evaluation plans.

Unhealthy Food at Your Fingertips: Cross-Sectional Analysis of the Nutritional Quality of Restaurants and Takeaway Outlets on an Online Food Delivery Platform in New Zealand.

Online food delivery (OFD) platforms have become increasingly popular due to advanced technology, which is changing the way consumers purchase food prepared outside of the home. There is limited research investigating the healthiness of the digital food environment and its influence on consumer choice and dietary behaviours. This study is the first to examine the nutritional quality and marketing attributes of menu items from popular independent and franchise restaurants and takeaway outlets on New Zealand's market leading OFD platform (UberEATS®). A total of 374 popular independent and franchise restaurants and takeaway outlets were identified to form a database of complete menus and marketing attributes. All 25,877 menu items were classified into 38 food and beverage categories based on the Australian Dietary Guidelines. Of complete menus, 73.3% (18,955/25,877) were discretionary. Thirty-six percent (9419/25,877) were discretionary cereal-based mixed meals, the largest of the 38 categories. Discretionary menu items were more likely to be categorized as most popular (OR: 2.0, 95% CI 1.7−2.2), accompanied by a photo (OR: 1.7, 95% CI 1.6−1.8), and offered as a value bundle (OR: 4.6, 95% CI 3.2−6.8). Two of the three discretionary mixed meal categories were significantly less expensive than their healthier counterparts (p < 0.001). The overwhelming availability and promotion of discretionary choices offered by restaurants and takeaway outlets on OFD platforms have implications for public health policy. Further research to explore direct associations between nutritional quality and consumers' dietary choices is required.

The Use of Mobile-Based Ecological Momentary Assessment (mEMA) Methodology to Assess Dietary Intake, Food Consumption Behaviours and Context in Young People: A Systematic Review.

Mobile-based ecological momentary assessment (mEMA) offers a novel method for dietary assessment and may reduce recall bias and participant burden. This review evaluated mEMA methodology and the feasibility, acceptability and validity as a dietary assessment method in young people. Five databases were searched from January 2008 to September 2021 for studies including healthy young people aged 16-30 years and used mEMA for obtaining dietary intake data, food consumption behaviours and/or contextual factors. Data on the method used to administer mEMA, compliance with recording and validation were extracted. A total of 46 articles from 39 independent studies were included, demonstrating a wide variation in mEMA methods. Signal-contingent prompting (timed notification to record throughout the day) was used in 26 studies, 9 used event-contingent (food consumption triggered recordings), while 4 used both. Monitoring periods varied and most studies reported a compliance rate of 80% or more. Two studies found mEMA to be burdensome and six reported mEMA as easy to use. Most studies (31/39) reported using previously validated questions. mEMA appears to be a feasible and acceptable methodology to assess dietary intake and food consumption in near real time.

Underinvestment in nutrition research for at-risk populations: An analysis of research funding awarded in Australia from 2014 to 2021.

AIM: To determine the proportion of research projects funded by the National Health and Medical Research Council and Australian Research Council research funding from 2014 to 2021 that aimed to understand or improve dietary behaviours for at-risk populations in Australia and estimate the proportion of total funding allocated during this period. METHODS: Retrospective analysis of the publicly available National Health and Medical Research Council and Australian Research Council funding grants over the 8 years from 2014 to 2021 (n = 18 098). At-risk dietary populations included people living in rural and remote Australia, Aboriginal and Torres Strait Islander people, or people living in socioeconomically disadvantaged areas. Descriptive analysis was undertaken. RESULTS: In total, 144 out of 18 098 (0.8%) individual grants totalling $96.8 million were identified relating to nutrition research from 2014 to 2021. Out of the 144, only 21 ($19.6 million; 0.1%) of all National Health and Medical Research Council grants were identified for nutritionally at-risk populations, with the majority focused on Aboriginal and Torres Strait Islander people (15/21). The National Health and Medical Research Council and Australian Research Council grants that aimed to improve human dietary behaviours increased by 0.66% and 0.58%, respectively, from 2014 to 2021. However, the National Health and Medical Research Council grants aiming to improve nutritional behaviours in at-risk populations decreased by 0.04% over the 8 years. CONCLUSIONS: Despite slight increases in the proportions of funding to improve dietary behaviours over the past decade, nutrition research specifically targeting at-risk groups is scarce and appears to have decreased over time. Insufficient investment in research for these groups presents a risk for widening health disparities now and into the future. As such, they must be further supported and considered in the design of future funding schemes.

Perspective: Are Online Food Delivery Services Emerging as Another Obstacle to Achieving the 2030 United Nations Sustainable Development Goals?

Online food delivery usage has soared during the 2019 novel coronavirus (COVID-19) pandemic which has seen increased demand for home-delivery during government mandated stay-at-home periods. Resulting implications from COVID-19 may threaten decades of development gains. It is becoming increasingly more important for the global community to progress toward sustainable development and improve the wellbeing of people, economies, societies, and the planet. In this perspective article, we discuss how the rising use of these platform-to-consumer delivery operations may impede advances toward the United Nations 2030 Sustainable Development Goals (SDGs). Specifically, online food delivery services may disrupt SDGs that address good health and wellbeing, responsible consumption and production, climate action and decent work and economic growth. To mitigate potential negative impacts of these meal delivery apps, we have proposed a research and policy agenda that is aligned with entry points within a systems approach identified by the World Health Organization. Food industry reforms, synergised public health messaging and continuous monitoring of the growing impact of online food delivery should be considered for further investigation by researchers, food industry, governments, and policy makers.

Navigating the Online World of Lifestyle Health Information: Qualitative Study With Adolescents.

BACKGROUND: Adolescence is a critical life stage characterized by an interplay of biological, social, and environmental factors. Such factors influence lifestyle health-related trajectories, including dietary behaviors, physical activity levels, body weight, and sleep. Generation Z (born 1995-2015) is the most internet-dependent and technologically savvy generation in history with increasing rates of smartphone ownership across high- and low-income countries. Gaps exist in understanding what online platforms adolescents are using and barriers and facilitators of these platforms to seek lifestyle health information. OBJECTIVE: We evaluated adolescents' perceptions on the use of contemporary digital platforms (websites, social media platforms, smartphone apps) to seek lifestyle heath information or advice. METHODS: Virtual focus groups were held via Zoom teleconference between July 2021 and August 2021. Eligible participants were 13 years to 18 years old, were living in Australia, and had searched for online lifestyle health information in the previous 3 months. For this study, lifestyle health information referred to key behaviors and risk factors for chronic disease, namely, diet, physical activity, weight management, and sleep. Participants were recruited through an existing database of research participants and networks of the research team. Focus groups were analyzed using the framework approach, in which data are systematically searched to recognize patterns in the data and manage, analyze, and identify themes. Focus group audio files were transcribed verbatim and independently coded by 2 researchers (RR, SSJ). Through an iterative, reflexive process, a final coding matrix was agreed on by all researchers and used to thematically analyze the data. RESULTS: We held 5 focus groups (n=32; mean age: 16.3 [SD 1.4] years; 18/32, 56% female; 13/32, 41% spoke language other than English at home). Thematic analysis revealed participants searched for information both actively (eg, on Google or YouTube) and passively (eg, scrolling social media and using existing apps preloaded to their smartphone such as Apple Health, Samsung Health, or Google Fit apps). Participants identified that the most helpful information was well-presented in terms of aesthetic appeal and layout and came from a credible and reliable source (eg, any sponsorships disclosed), and they expressed the need for the information to be relatable. Mixed views were reported for the application of lifestyle health information found online. Some participants reported behavior change, while others noted that certain advice was hard to maintain and incorporate into their lifestyle. CONCLUSIONS: This study highlights the abundance and complexity of lifestyle health information online for adolescents. Adolescents in the digital age seek access to information that is appealing, credible, relevant, and actionable for lifestyle health behaviors. To appeal to needs of adolescents, future interventions for adolescents relating to lifestyle health must consider co-design methodological approaches. Furthermore, the regulation of lifestyle health information available online warrants further investigation.

The Use of Portion Control Plates to Promote Healthy Eating and Diet-Related Outcomes: A Scoping Review.

The role of portion control plates in achieving healthy diets is unclear. The aim of this scoping review was to systematically map findings from peer reviewed and grey literature to provide evidence for the use of portion control plates to promote healthy eating and nutrition-related knowledge in children and adults. A secondary aim was to review the design characteristics of portion control plates. The search was conducted in four databases, including Medline, CINAHL, Embase, and PsycInfo, and grey literature sources following the PRISMA scoping review guidelines. A total of 22 articles comprising 23 intervention studies and 8 from grey literature were included. It was found that the various two-dimensional and three-dimensional portion control plates examined were effective tools for better portion size selection in healthy children and adults. Most portion control plates dedicated half the plate to vegetables, a quarter to protein, and a quarter to carbohydrates. The use of portion control plates in nutrition interventions appears to promote weight loss among those with overweight and obesity and/or type 2 diabetes. However, portion control plates were mostly used as part of multicomponent interventions and the effectiveness of the portion control plate as a stand-alone educational resource or portion control tool alone was uncertain. Further interventional research is indicated to investigate portion plates as tools to improve dietary behaviours and food consumption at the population level.

How Helpful and What Is the Quality of Digital Sources of Healthy Lifestyle Information Used by Australian Adolescents? A Mixed Methods Study.

To evaluate the digital platforms most used by adolescents for healthy lifestyle information, perceived helpfulness of platform information, helpfulness for positive behaviour changes, and quality of platforms' lifestyle health information. Mixed-methods study including a cross-sectional online survey and content analysis. Eligible participants were 13-18-years; living in Australia; and had searched online for healthy lifestyle behaviour (nutrition, physical activity, weight management, sleep) information in the previous three months. Survey items examined the use of digital platforms, self-perceived helpfulness, usefulness for positive behaviour, and popular content. Data were analysed using descriptive statistics and ordinal logistic regression models. Content analysis was performed on popular digital content to evaluate expertise, objectivity, transparency, popularity, and relevance. In total, 297 participants completed the survey (62.3% female; 15.8 [SD1.5] years). Seventy-eight percent and 77% of participants reported using websites and social media, respectively, for seeking healthy lifestyle information. Websites and social media were rated as somewhat helpful by 43% and 46% of participants, respectively. Sixty-six percent and 53% of participants agreed/strongly agreed smartphone apps and social media were helpful for positive behaviour change, respectively. Helpfulness did not differ by age or gender. We evaluated 582 popular digital content; 38% were produced by a commercial company. Only 7% of content was from health organisations, 10% from health professionals and only 10% of content was objective, and 14% was transparent. Adolescents extensively utilise websites and social media for health information, yet popular content has limited objectivity and transparency. Governments and health organisations should consider creating age-appropriate digital information for healthy lifestyle behaviours.

#SupportLocal: how online food delivery services leveraged the COVID-19 pandemic to promote food and beverages on Instagram.

OBJECTIVE: To explore the promotion of discretionary foods/beverages and marketing strategies employed by the top three online food delivery services' (OFDS) Instagram accounts in three countries before and during the coronavirus disease 2019 (COVID-19) pandemic. DESIGN: Publicly available data were extracted for the top three OFDS Instagram accounts for Australia, United Kingdom (UK) and the United States of America (USA) from March to May 2019 and 2020. Food/beverage items from posts were classified as 'discretionary' or from the five food groups (FFG) according to the Australian Dietary Guidelines. Marketing strategies were coded using an existing framework. Posts referring to COVID-19 were coded under four marketing strategies: (i) appropriating frontline workers; (ii) combatting the pandemic; (iii) selling social distancing; and (iv) accelerating digitalisation. RESULTS: From 581 posts, 618 food/beverage items were shown, of which 69 % (427/618) were classified as discretionary. In 2019, the most used marketing strategies were product imagery (unbranded) (137/195, 70 %), links (111/195, 57 %) and sponsorships/partnerships (58/195, 30 %). In 2020, the most used were links (252/386, 68 %), product imagery (unbranded) (179/386, 49 %) and branding elements (175/386, 45 %). The most common COVID-19 marketing strategy was combatting the pandemic (76/123, 62 %) followed by selling social distancing (53/123, 43 %), appropriating frontline workers (34/123, 28 %) and accelerating digitalisation (32/123, 26 %). CONCLUSIONS: Following the COVID-19 pandemic, OFDS adapted their marketing, creating content with the theme of 'combatting the pandemic'. Due to the growing number of discretionary foods/beverages promoted on Instagram, this highlights the need for policy action to counter the potential influence social media platforms have on dietary behaviours.

Hunger for Home Delivery: Cross-Sectional Analysis of the Nutritional Quality of Complete Menus on an Online Food Delivery Platform in Australia.

Online food delivery (OFD) platforms have changed how consumers purchase food prepared outside of home by capitalising on convenience and smartphone technology. Independent food outlets encompass a substantial proportion of partnering outlets, but their offerings' nutritional quality is understudied. Little is also known as to how OFD platforms influence consumer choice. This study evaluated the nutritional quality and marketing attributes of offerings from independent takeaway outlets available on Sydney's market-leading OFD platform (UberEats®). Complete menus and marketing attributes from 202 popular outlets were collected using web scraping. All 13841 menu items were classified into 38 food and beverage categories based on the Australian Dietary Guidelines. Of complete menus, 80.5% (11,139/13,841) were discretionary and 42.3% (5849/13,841) were discretionary cereal-based mixed meals, the largest of the 38 categories. Discretionary menu items were more likely to be categorised as most popular (OR: 2.5, 95% CI 1.9-3.2), accompanied by an image (OR: 1.3, 95% CI 1.2-1.5) and offered as a value bundle (OR: 6.5, 95% CI 4.8-8.9). Two of the three discretionary food categories were more expensive than their healthier Five Food Group counterparts (p < 0.02). The ubiquity of discretionary choices offered by independent takeaways and the marketing attributes employed by OFD platforms has implications for public health policy. Further research on the contribution of discretionary choices and marketing attributes to nutritional intakes is warranted.

Junk Food on Demand: A Cross-Sectional Analysis of the Nutritional Quality of Popular Online Food Delivery Outlets in Australia and New Zealand.

The demand for convenience and the increasing role of digital technology in everyday life has fueled the use of online food delivery services (OFD's), of which young people are the largest users globally. OFD's are disrupting traditional food environments, yet research evaluating the public health implications of such services is lacking. We evaluated the characteristics and nutritional quality of popular food outlets on a market-leading platform (UberEATS®) in a cross-sectional observational study conducted in two international cities: Sydney (Australia) and Auckland (New Zealand). A systematic search using publicly available population-level data was used to identify geographical areas with above-average concentrations (>30%) of young people (15-34-years). A standardized data extraction protocol was used to identify the ten most popular food outlets within each area. The nutritional quality of food outlets was assessed using the Food Environment Score (FES) (range: -10 'unhealthiest' to 10 'healthiest'). Additionally, the most popular menu items from each food outlet were classified as discretionary or core foods/beverages according to the Australian Dietary Guidelines. The majority of popular food outlets were classified as 'unhealthy' (FES range -10 to -5; 73.5%, 789/1074) and were predominately takeaway franchise stores (59.6%, 470/789, e.g., McDonald's®). 85.9% of all popular menu items were discretionary (n = 4958/5769). This study highlights the pervasion and accessibility of discretionary foods on OFD's. This study demonstrated that the most popular food outlets on the market-leading online food delivery service are unhealthy and popular menu items are mostly discretionary foods; facilitating the purchase of foods of poor nutritional quality. Consideration of OFD's in public health nutrition strategies and policies in critical.

Probing tethered targets of a single biomolecular complex with atomic force microscopy.

DNA origami shows tremendous promise as templates for the assembly of nano-components and detection of molecular recognition events. So far, the method of choice for evaluating these structures has been atomic force microscopy (AFM), a powerful tool for imaging nanoscale objects. In most cases, tethered targets on DNA origami have proven to be highly effective samples for investigation. Still, while maximal assembly of the nanostructures might benefit from the greatest flexibility in the tether, AFM imaging requires a sufficient stability of the adsorbed components. The balance between the tether flexibility and sample stability is a major, poorly understood, concern in such studies. Here, we investigated the dependence of the tethering length on molecular capture events monitored by AFM. In our experiments, single biotin molecules were attached to DNA origami templates with various linker lengths of thymidine nucleotides, and their interaction with streptavidin was observed with AFM. Our results show that the streptavidin-biotin complexes are easily detected with short tethered lengths, and that their morphological features clearly change with the tethering length. We identify the functionally useful tether lengths for these investigations, which are also expected to prove useful in the construction and further application of DNA origami in bio-nanotechnology studies.