The substantial changes in the physical and social environment during the transition from primary to secondary school may significantly impact adolescents’ energy balance-related behaviours (i.e. dietary behaviour, sedentary behaviour, sleep behaviour and physical activity (PA)). This is the first review systematically summarising evidence on changes in four energy balance-related behaviours of adolescents across the school transition from primary to secondary school.

For this systematic review, the electronic databases Embase, PsycINFO and SPORTDiscus were searched for relevant studies from inception to August 2021. PubMed was searched for relevant studies from inception to September 2022. Inclusion criteria were: (i) longitudinal studies reporting; (ii) one or more energy balance-related behaviours; and (iii) across the school transition, that is, with measurement(s) during both primary and secondary school.

Transition from primary to secondary school

Adolescents across the transition from primary to secondary school.

Thirty-four studies were eligible. We found strong evidence for an increase in sedentary time, moderate evidence for a decrease in fruit and vegetable consumption, and inconclusive evidence for a change in total, light, and moderate-to-vigorous PA, active transport, screen time, unhealthy snack consumption, and sugar-sweetened beverages consumption among adolescents across the school transition.

During the transition from primary to secondary school, sedentary time and fruit and vegetable consumption tend to change unfavourably. More high-quality, longitudinal research is needed specifically on changes in energy balance-related behaviour across the school transition, especially regarding sleep behaviour. (Prospero registration: CRD42018084799)

To assess dietary behaviours and related lifestyles according to the presence or absence of skipping breakfast.

We analysed the cross-sectional data from a baseline survey of a large-scale population-based cohort study in Japan conducted in 2011–2016. Participants provided information on dietary behaviours and lifestyles through a self-administered questionnaire. Skipping breakfast was defined as not eating breakfast at least once a week and was classified according to the frequency of skipping breakfast as 1–2, 3–4 or ≥5 times/week.

Sixteen municipalities in seven prefectural areas across Japan under the Japan Public Health Centre-based prospective study for the Next Generation.

112 785 residents (51 952 males and 60 833 females) aged 40–74 years.

After adjustment for age, socio-demographic status, drinking status and smoking status, individuals who skipped breakfast at least once a week, compared with those who ate breakfast every day, were more likely to have adverse dietary behaviours such as frequent eating out (multivariable OR = 2·08, 95 % CI (1·96, 2·21) in males and 2·15, 95 % CI (1·99, 2·33) in females), frequent eating instant foods (1·89, 95 % CI (1·77, 2·01) in males and 1·72, 95 % CI (1·56, 1·89) in females). They had late bedtime (1·85, 95 % CI (1·75, 1·95) in males and 1·98, 95 % CI (1·86, 2·11) in females) and living alone (2·37, 95 % CI (2·17, 2·58) in males and 2·02, 95 % CI (1·83, 2·21) in females), using the logistic regression model.

Both adult males and females who skipped breakfast were likely to eat out, to have a dietary habit of eating instant foods and have lifestyles such as late bedtime and living alone than those who ate breakfast.

To explore communities’ perspectives on the factors in the social food environment that influence dietary behaviours in African cities.

A qualitative study using participatory photography (Photovoice). Participants took and discussed photographs representing factors in the social food environment that influence their dietary behaviours. Follow-up in-depth interviews allowed participants to tell the ‘stories’ of their photographs. Thematic analysis was conducted, using data-driven and theory-driven (based on the socio-ecological model) approaches.

Three low-income areas of Nairobi (n 48) in Kenya and Accra (n 62) and Ho (n 32) in Ghana.

Adolescents and adults, male and female aged ≥13 years.

The ‘people’ who were most commonly reported as influencers of dietary behaviours within the social food environment included family members, friends, health workers and food vendors. They mainly influenced food purchase, preparation and consumption, through (1) considerations for family members’ food preferences, (2) considerations for family members’ health and nutrition needs, (3) social support by family and friends, (4) provision of nutritional advice and modelling food behaviour by parents and health professionals, (5) food vendors’ services and social qualities.

The family presents an opportunity for promoting healthy dietary behaviours among family members. Peer groups could be harnessed to promote healthy dietary behaviours among adolescents and youth. Empowering food vendors to provide healthier and safer food options could enhance healthier food sourcing, purchasing and consumption in African low-income urban communities.

This study aimed to explore the facilitators and barriers to healthy dietary behaviour in adults with type 2 diabetes mellitus (T2DM) in Kenya.

A qualitative descriptive design using telephone interviews was applied. An interview guide was developed through a modified theoretical framework.

This study was conducted in selected hospitals in Nakuru County, located in west-central Kenya.

A two-step sampling strategy was used to select hospitals and study participants. Adult participants aged 30 to 85 years, with T2DM from six hospitals were selected based on their ability to openly elaborate on the theme of dietary behaviour.

Thirty respondents were interviewed (mean age 62 years; 43·3 % females). The average duration of the interviews was 32:02 min (sd 17·07). The highest-ranking internal facilitators of healthy dietary behaviour were knowledge of healthy food choices, gardening, self-efficacy, food preparation skills and eating at home. External facilitators included inaccurate beliefs and information on food and diet, education by healthcare workers, food availability, proximity to food selling points and family support. Internal barriers included tastes and preferences, health conditions barring intake of certain foods, and random eating of unhealthy foods. External barriers included socio-economic factors, seasonal unavailability of fruits and food safety concerns.

Facilitators and barriers to healthy dietary behaviour among Kenyan adults with T2DM are related to food literacy and include selection, preparation and eating. Interventions to enhance healthy dietary behaviour should target context-specific knowledge, skills and self-efficacy.

This study aimed to examine the intrapersonal, interpersonal, environmental and macrosystem influences on dietary behaviours among primary school children in Singapore.

A qualitative interpretive approach was used in this study. Focus group discussions guided by the socio-ecological model (sem), of which transcripts were analysed deductively using the sem and inductively using thematic analysis to identify themes at each sem level.

Two co-educational public primary schools in Singapore.

A total of 48 children (n 26 girls) took part in the semi-structured focus group discussions. Their mean age was 10·8 years (sd = 0·9, range 9–12 years), and the majority of the children were Chinese (n 36), along with some Indians (n 8) and Malays (n 4).

Children’s knowledge of healthy eating did not necessarily translate into healthy dietary practices and concern for health was a low priority. Instead, food and taste preferences were pivotal influences in their food choices. Parents had a large influence on children with regards to their accessibility to food, their attitudes and values towards food. Parental food restriction led to some children eating in secrecy. Peer influence was not frequently reported by children. Competitions in school incentivised children to consume fruits and vegetables, but reinforcements from teachers were inconsistent. The proximity of fast-food chains in the neighbourhood provided children easy access to less healthy foods. Health advertisements on social media rather than posters worked better in drawing children’s attention.

Findings highlighted important factors that should be considered in future nutrition interventions targeting children.

Social media analytics (SMA) has a track record in business research. The utilisation in nutrition research is unknown, despite social media being populated with real-time eating behaviours. This rapid review aimed to explore the use of SMA in nutrition research with the investigation of dietary behaviours.

The review was conducted according to rapid review guidelines by WHO and the National Collaborating Centre for Methods and Tools. Five databases of peer-reviewed, English language studies were searched using the keywords ‘social media’ in combination with ‘data analytics’ and ‘food’ or ‘nutrition’ and screened for those with general population health using SMA on public domain, social media data between 2014 and 2020.

The review identified 34 studies involving SMA in the investigation of dietary behaviours. Nutrition topics included population nutrition health investigations, alcohol consumption, dieting and eating out of the home behaviours. All studies involved content analysis with evidence of surveillance and engagement. Twitter was predominant with data sets in tens of millions. SMA tools were observed in data discovery, collection and preparation, but less so in data analysis. Approximately, a third of the studies involved interdisciplinary collaborations with health representation and only two studies involved nutrition disciplines. Less than a quarter of studies obtained formal human ethics approval.

SMA in nutrition research with the investigation of dietary behaviours is emerging, nevertheless, if consideration is taken with technological capabilities and ethical integrity, the future shows promise at a broad population census level and as a scoping tool or complementary, triangulation instrument.

Diet and nutrition in childhood has been associated with the risk of chronic disease later in life. The aim of this review was to identify key characteristics of successful experiential nutrition interventions aimed to change nutrition-related cognitive and behavioural outcomes in primary schoolchildren.

A systematic literature review was undertaken using search terms (‘food security’, ‘school’, ‘nutrition’ and ‘program’) applied to five scientific databases (CINAHL, Scopus, Web of Science, Medline and Academic Search complete), with outcomes defined as nutrition-related knowledge, attitudes and/or dietary behaviours.

Primary school-aged children exposed to interventions conducted, at least partially, on school grounds.

A total of 3800 articles were identified from the initial search and manual searching, of which sixty-seven articles were eligible for inclusion. Forty-two articles met the criteria of being successful, defined as achieving significant differences in outcomes of interest, accompanied by a demonstrated reach. Interventions included school gardens (n 9), food provision (n 5), taste testing (n 8), cooking classes (n 10) and multicomponent programmes (n 10). Nutrition education (when combined with taste testing), cooking-related activities and gardening interventions increased children’s willingness to taste unfamiliar foods including new fruits and vegetables, improved their cooking and food preparation skills and increased nutritional knowledge.

This review provides evidence that nutrition education programmes in primary schoolchildren that are experiential in nature are most likely to be successful if they include multiple strategies, have parental involvement and focus specifically on vegetable intake.

To explore determinants of dietary and physical activity behaviours among women of reproductive age.

Data were collected through focus group discussions (FGD). The FGD guide was based on a modified theoretical framework; theory of planned behaviour was incorporated with constructs of health belief model, precaution adoption process model, social cognitive and social support theory. Discussions were audio recorded, transcribed verbatim and analysed thematically.

Kampala, Uganda.

Women were categorised into young adults; 18–34 years and adults; 35–45 years

Separate FGD with independent participants were conducted for dietary and physical activity behaviours until data saturation was achieved. Six FGD were conducted per behaviour. Determinants of dietary behaviours at intra-individual level included gaps in food skills, knowledge and self-efficacy, food safety concerns, convenience, finances and physiological satisfaction. The social-cultural norms were relationship between vegetable consumption and low social status, consideration of fruits as a snack for children and not food and habitual orientation towards carbohydrate foods. At environment level, social networks and increased availability of energy-dense, nutrient poor, street and processed foods influence dietary behaviour. For physical activity, intra-individual determinants were knowledge gaps and self-efficacy, while socio-cultural norms included gender stereotypes. Home (limited space and sedentary entertainment like social media and TV) and physical environment (cheap motorised transportation) influence physical activity.

The existing cultural beliefs promote dietary and physical activity behaviours which are divergent from healthy recommendations. Therefore, a comprehensive intervention is needed to address socio-cultural misconceptions, financial and time limitations in urban Uganda.

To assess factors influencing dietary behaviours of adolescents in Addis Ababa, Ethiopia.

Using the qualitative participatory method Photovoice, participants received training on the basics of Photovoice and took photographs related to (un)healthy eating in their environment. Transcripts of individual interviews, focus group discussions and photographs were coded for thematic analysis.

One private and one public school located in the same, central neighbourhood in Addis Ababa, Ethiopia to explore how school populations of different socio-economic status experience the same neighbourhood environment.

Twenty-six adolescents aged 14–19 years old, of which there were seventeen girls and nine boys.

Findings from the current study indicate that food safety concerns appear to be the major influencing factors for adolescents’ dietary choices. Unhealthy and unsafe foods appear to be widely available and/or affordable in adolescents’ neighbourhoods and almost half of the photographs taken by adolescents depicted poor hygiene conditions related to food vendors. Participants considered foods available in their environments as generally unsafe, calling for more packaged food.

Concerns for food safety, hygiene and affordability are the dominating factors for adolescents’ food choices. These concerns, together with limited nutrition knowledge and preference for packaged foods, could make cheap, ultra-processed packaged foods more desirable.

The aim of this study was to investigate the association of the number of hours of nutrition education and teachers’ qualifications with nutrition knowledge and dietary behaviour in students.

In this representative cross-sectional study, socio-demographic data, anthropometric measurements, socio-economic status (SES), physical fitness, nutrition knowledge and eating habits were assessed. Differences between groups were tested by χ2 and t tests. Multiple linear and logistic regression modelling was used to examine the relationship between demographic characteristics, lifestyle and dietary behaviours, nutrition knowledge, nutrition-trained teachers and number of nutrition lessons.

Sixteen secondary schools in urban (n 6) and rural regions (n 10) of Tyrol, Western Austria.

Students (n 513) aged 14·2 (sd 0·7) years.

Higher nutrition knowledge was significantly associated with attending rural school (P = 0·001), having no migration background (P < 0·001), (very) good physical activity behaviour (P = 0·040), non-trained teacher (P = 0·006) but higher number of hours of nutrition education (P = 0·013). Regression models showed that higher nutrition knowledge was independently associated with lower intake of meat and iced tea and higher intake of vegetables and plant-based oils. A higher amount of nutrition education (h/week) was significantly associated with higher intake of dark (wholegrain) bread, lower intake of meat and of energy drinks sweetened with sweeteners.

Our results suggest that more hours in nutrition education result in higher nutrition knowledge and greater nutrition literacy, which may lead to health-promoting dietary habits. School-based nutrition education can be seen as preventive measure to increase nutritional competences in adolescents independent of their SES.

To identify factors influencing dietary behaviours in urban food environments in Africa and identify areas for future research.

We systematically reviewed published/grey literature (protocol CRD4201706893). Findings were compiled into a map using a socio-ecological model on four environmental levels: individual, social, physical and macro.

Urban food environments in Africa.

Studies involving adolescents and adults (11–70 years, male/female).

Thirty-nine studies were included (six adolescent, fifteen adolescent/adult combined and eighteen adult). Quantitative methods were most common (twenty-eight quantitative, nine qualitative and two mixed methods). Studies were from fifteen African countries. Seventy-seven factors influencing dietary behaviours were identified, with two-thirds at the individual level (45/77). Factors in the social (11/77), physical (12/77) and macro (9/77) environments were investigated less. Individual-level factors that specifically emerged for adolescents included self-esteem, body satisfaction, dieting, spoken language, school attendance, gender, body composition, pubertal development, BMI and fat mass. Studies involving adolescents investigated social environment-level factors more, for example, sharing food with friends. The physical food environment was more commonly explored in adults, for example, convenience/availability of food. Macro-level factors associated with dietary behaviours were food/drink advertising, religion and food prices. Factors associated with dietary behaviour were broadly similar for men and women.

The dominance of studies exploring individual-level factors suggests a need for research to explore how social, physical and macro-level environments drive dietary behaviours of adolescents and adults in urban Africa. More studies are needed for adolescents and men, and studies widening the geographical scope to encompass all African countries.

School-based interventions and policies encourage youths to include and consume fruits and vegetables at lunchtime via school lunches, but limited research has examined how these behaviours compare when youths have home-packed lunches. The objective of the present study was to compare fruit and vegetable contents and consumption among students having school or home-packed lunches over the school week.

Participants were observed over five consecutive days at school lunchtime. Trained analysts estimated students’ lunchtime fruit and vegetable contents and consumption using digital imaging. Mixed models examined associations between fruit and vegetable dietary behaviours and lunch source (school v. home-packed), controlling for student gender, grade and school.

Three elementary schools in northern California, USA.

Fourth-, fifth- and sixth-grade students (nchildren 315; nobservations 1421).

Students were significantly less likely to have and to consume fruits and vegetables (all P<0·05) when having home-packed lunches, compared with when having school lunches. Among those who did have or did consume these foods, having a home-packed lunch was associated with consuming significantly less fruit (P<0·05) but no differences for other dietary outcomes.

The study adds to a growing body of literature indicating shortfalls in fruit and vegetable contents and consumption associated with having a home-packed lunch, relative to having a school lunch. Findings suggest that school-based interventions, particularly when targeting home-packed lunches, should focus on whether or not these foods are included and consumed, with less emphasis on quantities.

Concerns have been raised about the potential health impact of ultra-processed foods (UPF) in the diet. Our objective was to investigate the contribution of UPF in the diet in a large French population and its association with sociodemographic factors and dietary patterns.

Cross-sectional analysis of dietary data from 74 470 participants in the web-based NutriNet-Santé cohort. UPF were identified in repeated 24 h records and the proportion (in weight) of UPF in the total diet (UPFp) was computed for each participant. Associations of sociodemographic characteristics and UPFp in quartiles were assessed using multivariate multinomial logistic regression. Food group consumption and nutrient intakes across quartiles of UPFp were estimated using linear regression adjusted for sociodemographic factors and energy intake.

France.

UPF contributed 18·4 % of the foods consumed in weight and 35·9 % of total energy intake. Higher UPFp consumption was independently associated with male gender, younger age, lower education, smoking, and overweight and obesity (all P<0·0001). Participants in the highest UPFp quartile consumed lower amounts of fruit and vegetables (difference between quartile 4 and quartile 1 of UPFp, Δ=−180·3 g/d) and higher amounts of sweet products (Δ=68·5 g/d) and soft drinks (Δ=98·6 g/d; all P<0·0001). They had higher intakes of energy (Δ=610 kJ/d (145·7 kcal/d)) and added sugar (Δ=17·1 g/d), and lower intakes of fibre (Δ=−4·04 g/d), β-carotene (Δ=−1019·6 μg/d) and Ca (Δ=−87·8 mg/d; all P<0·0001).

UPF represent an important part of the diet in adults from the French general population and are associated with unbalanced nutritional intakes.

To identify determinants of diet in pregnancy, by detecting factors in our multiple-determinants life course framework that are associated with dietary patterns, quality or guideline adherence.

A systematic review of observational studies, published in English or German, was conducted. Sociodemographic, lifestyle, environmental and pregnancy-related determinants were considered. Four electronic databases were searched in January 2015 and updated in April 2016 and a total of 4368 articles identified. Risk of bias was assessed using adapted Newcastle–Ottawa Scales.

High- and upper-middle-income countries.

Pregnant or postpartum women reporting their dietary intake during pregnancy.

Seventeen publications of twelve studies were included and compared narratively due to heterogeneity. Diet in pregnancy was patterned along a social gradient and aligned with other health behaviours before and during pregnancy. Few studies investigated the influence of the social and built environment and their findings were inconsistent. Except for parity, pregnancy determinants were rarely assessed even though pregnancy is a physiologically and psychologically unique period. Various less well-researched factors such as the role of ethnicity, pregnancy intendedness, pregnancy ailments and macro-level environment were identified that need to be studied in more detail.

The framework was supported by the literature identified, but more research of sound methodology is needed in order to conclusively disentangle the interplay of the different determinants. Practitioners should be aware that pregnant women who are young, have a low education or do not follow general health advice appear to be at higher risk of inadequate dietary intake.

(i) To identify determinants of participation in the ‘Healthy School Canteen Program’, a programme that encourages schools to set up their canteen in a way that promotes healthy dietary behaviour. (ii) To compare food supply and actions between participating and non-participating schools. (iii) To investigate what reasons schools have to increase attention for nutrition in the curriculum.

A cross-sectional study based on information from questionnaires performed in 2010/2011.

All secondary schools (age group 12–18 years) in the Netherlands (n 1145).

Response was 33 % (n 375). Analyses included all schools with a canteen in which food is offered (28 %, n 325).

None of the investigated determinants was associated with participation. Participating schools offered significantly (P < 0·001) more of eleven inventoried healthy foods (e.g. sandwiches, (butter)milk, fruit, light soft drinks, yoghurt and salad) than non-participating schools. However, there was no difference in the number of less healthy products offered (e.g. candy bars, cakes and regular soft drinks). Participating schools reported more often that they took actions to improve dietary behaviour and more often had a policy on nutrition. Participating schools more often increased attention for nutrition in the curriculum in recent years than non-participating schools (57 % v. 43 %, P = 0·01). Reported reasons were similar and included media attention, eating behaviour of students and ‘overweight’.

Schools that participate in the programme seemed to offer more healthy products in their canteens and took more actions to improve dietary behaviour than non-participating schools. However, at all schools less healthy foods were also available.