Characteristics of Global Data on Adolescent's Dietary Intake: A Systematic Scoping Review.

Data on adolescents' dietary intake are essential to improve their diets and nutrition. However, the availability of (high-quality) data on adolescents' dietary intake is scarce with great global differences. We conducted a systematic scoping review to investigate the availability, characteristics, and gaps in global adolescent dietary data, following the Preferred Reporting Items for Systematic Reviews and Meta Analyses-Extension for Scoping Reviews checklist and guidelines (registered under PROSPERO no. 171170 https://www.crd.york.ac.uk/PROSPERO/). We included peer-reviewed and grey literature articles (2010 onwards) on the dietary intake of male and female adolescents (10-24 y). Studies from all countries and languages and including any information related to types of food consumed, diet composition, dietary diversity, or meal patterns were considered. We excluded studies with insufficient methodological information, unclear description of population, samples sizes <25, school-based data sets containing <6 schools, and studies that focused on pregnant or unhealthy study populations. Data, including year(s) of data collection, age, gender, sample size, dietary assessment methods, number of food items/groups, study design, location, and representativeness, were extracted. A total of 52,889 titles were identified and 722 articles, describing 1,322 data sets, were retained for analysis. Nationally representative, detailed dietary data for adolescents aged 10-24 y are still lacking, particularly in sub-Saharan Africa, South Asia, and low-income countries. Data quality and representativeness remain limited, highlighting the need for data disaggregation by age, gender, locality, comprehensive dietary information, and broader geographic coverage. A notable amount of data was available through grey literature, especially in data-scarce countries. The study underscores the importance of addressing adolescent nutrition, emphasizing the urgent need for more robust, accessible, and representative data on adolescents' dietary intake to support effective nutritional efforts.

Food choice in transition: adolescent autonomy, agency, and the food environment.

Dietary intake during adolescence sets the foundation for a healthy life, but adolescents are diverse in their dietary patterns and in factors that influence food choice. More evidence to understand the key diet-related issues and the meaning and context of food choices for adolescents is needed to increase the potential for impactful actions. The aim of this second Series paper is to elevate the importance given to adolescent dietary intake and food choice, bringing a developmental perspective to inform policy and programmatic actions to improve diets. We describe patterns of dietary intake, then draw on existing literature to map how food choice can be influenced by unique features of adolescent development. Pooled qualitative data is then combined with evidence from the literature to explore ways in which adolescent development can interact with sociocultural context and the food environment to influence food choice. Irrespective of context, adolescents have a lot to say about why they eat what they eat, and insights into factors that might motivate them to change. Adolescents must be active partners in shaping local and global actions that support healthy eating patterns. Efforts to improve food environments and ultimately adolescent food choice should harness widely shared adolescent values beyond nutrition or health.

Africa's Changing Food Environments and Nutritional Effects on Adults and Children.

Many low- and middle-income countries (LMICs) are experiencing profound changes in food environments, including a rapid growth of supermarkets and other modern retailers. Changing food environments can influence people's diets, nutrition, and health. While in many LMICs, undernutrition and micronutrient deficiencies are still widespread, problems of overweight, obesity, and related non-communicable diseases are also massively on the rise. Supermarkets seem to contribute to overweight and obesity among adults, but effects on children and adolescents could possibly be different. Here, we review the available evidence about the implications of supermarkets for people's diets, nutrition, and health. Particular emphasis is placed on recent studies from urban Kenya that used panel data and differencing techniques to identify causal effects on different age cohorts. The results from Kenya show that shopping in supermarkets contributes to higher consumption of processed and highly processed foods and lower consumption of unprocessed foods. These dietary changes lead to significant increases in the body mass index and the probability of being overweight/obese and pre-diabetic among adults. For children, the same increases in overweight are not observed. Instead, supermarket shopping increases child height-for-age Z-scores. Despite higher food processing levels, supermarkets enhance food variety and dietary diversity in the relatively poor households. The results confirm that the growth of supermarkets affects adult and child nutrition differently; while the effects on adults are negative, the effects on children are positive, especially in the Kenyan context where child undernutrition is still widespread. Better understanding the effects of changing food environments on different age cohorts and in different contexts is important to design strategies that can help to make food choices in LMICs healthier. More research in different geographical settings will be useful.

Supermarket purchase contributes to nutrition-related non-communicable diseases in urban Kenya.

BACKGROUND: While undernutrition and related infectious diseases are still pervasive in many developing countries, the prevalence of non-communicable diseases (NCD), typically associated with high body mass index (BMI), is rapidly rising. The fast spread of supermarkets and related shifts in diets were identified as possible factors contributing to overweight and obesity in developing countries. Potential effects of supermarkets on people's health have not been analyzed up till now. OBJECTIVE: This study investigates the effects of purchasing food in supermarkets on people's BMI, as well as on health indicators such as fasting blood glucose (FBG), blood pressure (BP), and the metabolic syndrome. DESIGN: This study uses cross-section observational data from urban Kenya. Demographic, anthropometric, and bio-medical data were collected from 550 randomly selected adults. Purchasing food in supermarkets is defined as a binary variable that takes a value of one if any food was purchased in supermarkets during the last 30 days. In a robustness check, the share of food purchased in supermarkets is defined as a continuous variable. Instrumental variable regressions are applied to control for confounding factors and establish causality. RESULTS: Purchasing food in supermarkets contributes to higher BMI (+ 1.8 kg/m2) (P<0.01) and an increased probability (+ 20 percentage points) of being overweight or obese (P<0.01). Purchasing food in supermarkets also contributes to higher levels of FBG (+ 0.3 mmol/L) (P<0.01) and a higher likelihood (+ 16 percentage points) of suffering from pre-diabetes (P<0.01) and the metabolic syndrome (+ 7 percentage points) (P<0.01). Effects on BP could not be observed. CONCLUSIONS: Supermarkets and their food sales strategies seem to have direct effects on people's health. In addition to increasing overweight and obesity, supermarkets contribute to nutrition-related NCDs. Effects of supermarkets on nutrition and health can mainly be ascribed to changes in the composition of people's food choices.

Maternal nutrition knowledge and child nutritional outcomes in urban Kenya.

We examine the link between maternal nutrition knowledge and nutritional outcomes of children and adolescents (5-18 years) measured in terms of height-for-age Z-scores (HAZ). One particular focus is on the role of different types of nutrition knowledge. The analysis builds on household-level and individual-level data collected in urban Kenya in 2012 and 2015. Various regression models are developed and estimated. Results show that maternal nutrition knowledge - measured through an aggregate knowledge score - is positively associated with child HAZ, even after controlling for other influencing factors such as household living standard and general maternal education. However, disaggregation by type of knowledge reveals important differences. Maternal knowledge about food ingredients only has a weak positive association with child HAZ. For maternal knowledge about specific dietary recommendations, no significant association is detected. The strongest positive association with child HAZ is found for maternal knowledge about the health consequences of not following recommended dietary practices. These findings have direct relevance for nutrition and health policies, especially for designing the contents of educational campaigns and training programs.