A study published in the Open Access journal Nutrients by researchers from University of South Australia explores detrimental lifestyle behaviours among adolescents.

Adolescence is a critical stage of development, often described as both exciting and tumultuous as teenagers stumble their way through brand new life experiences. Importantly, this time is exceptionally sensitive to external factors that shape fundamental components of the child’s physical and mental health.

“The teenage years are a critical window for growth and development – physically, mentally, and emotionally – and they set the foundation for long-term health,” Dr Li says, author of the study.

This article will explore the rise in unhealthy lifestyle factors analysed in the study, including sedentary behaviours and consumption of ultra-processed food.

Furthermore, we discuss the results of the study and how the authors identified patterns associated with the behaviours, to reveal links with environmental and socioeconomic backgrounds.

The rise in sedentary behaviours

Teenage development is a highly sensitive stage of human growth. During this time, lifestyle factors are of critical importance to ensure that teenagers are getting everything they need to keep healthy and well throughout their youth until adulthood.

With an exponential rise in time spent doing sedentary activities amongst the population, adults are moving less, according to the World Health Organization (WHO).

Sedentary activities come in many forms but encompasses extended periods of sitting or lying down and not moving. Watching television and using the computer are types of sedentary activities. More recently, it also includes excessive time spent on addictive social media platforms, streaming services and the overwhelming amount of time consuming online content.

This overconsumption can have its own catalogue of negative repercussions, such as sleep disruptions and feelings of anxiety, which we explore in another article discussing the importance of taking a break from screens.

Critically, studies have shown that sedentary behaviour has a significant negative impact on health and quality of life. It is linked with an increased risk of developing chronic metabolic and cardiovascular disease, such as type 2 diabetes and heart disease, and even some types of cancers.

Ultra processed food and fast-food consumption

The 1980s brought a wave of industrially manufactured convenience food, eventually termed ultra-processed food (UPF). This encompasses refined foods made with numerous additives and flavour enhancers that are not found in normal kitchens at home. UPF products include things like fizzy drinks and fast-food items. It also includes more unsuspecting food items, like sliced bread, flavoured yogurts and cereals.

Research now shows that ultra processed food is worryingly linked to an array of physical health conditions as well as impacting mental health. Most UPF, especially fast food, contain high levels of salt and fat, with low levels of other essential nutrients and vitamins which are present in whole foods. These key nutrients are important for our body to function properly and to keep well.

Research shows that high levels of sedentary behaviour in combination with UPF consumption can increase things like anxiety-induced sleep disturbance and increase the risk of developing mental health issue such as depression and anxiety. Sleep is of critical importance for our bodies to function properly, particularly during adolescence, where it plays a key role in brain development, emotional regulation and development of the immune system.

“…With junk food so readily available, and physical activity often replaced by screen time, more teens are picking up multiple unhealthy habits that could lead to serious health issues down the track.”- Dr. Li explains.

Therefore, unhealthy lifestyles, such as sedentary behaviours and high levels of UPF consumption can be detrimental to physical and mental well-being in numerous ways.

Researchers from the University of South Australia unveiled the statistics of adolescents who have acquired these lifestyle choices, discussing the potential causes and their implications.

Majority of teens have a poor diet & don’t move enough

The researchers carried out a multilevel analysis from data obtained from school-based surveys to understand the extent to which unhealthy behaviours impacted adolescent health and well-being. The study explores various unhealthy lifestyle behaviours, including diet and levels of physical activity, and their impact on 293,770 adolescents from 73 countries and territories across five WHO regions.

They found that:

• 85% did not get enough exercise
• 80% did not eat enough fruit and vegetables
• 50% regularly consumed fast food
• 39% had too many soft drinks
• 32% spent excessive time on screens.

The results highlight the unfortunate issue that globally, teenagers are not consuming the right foods, are spending too much time on screens and not moving enough. These behaviours can have detrimental knock-on on effects on children’s health and future.

Importantly, the authors saw that these unhealthy behaviours may be associated with and influenced by certain familial, environmental and socio-economic factors. Specifically, the results showed that teenagers from higher income countries, which includes the Americas and countries within the Eastern Mediterranean, were more likely to adopt these unhealthy behaviours.

“Some of what we see comes down to rapid urbanisation, sedentary school environments, and limited access to safe recreational spaces, particularly in low- and middle-income countries. On top of this, taste preferences, household income, and limited availability of fresh produce – especially in disadvantaged areas – make healthy choices harder to access and maintain.”- Dr. Li.

Protective measures against unhealthy behaviours

The authors found certain protective factors which helped reduce unhealthy behaviours. This included familial support and a strong sense of community for the teenagers.

“When teenagers have supportive families and a supportive peer group, their risk of having four or more unhealthy behaviours reduces by 16% and 4% respectively. Similarly, food-secure households also reduce risk by 9%.”

These statistics highlight the complexity of the issue at hand, with the presence of unhealthy behaviours in teenagers tying into factors such as family background and socioeconomic status.

The authors discuss how development of better frameworks for adolescents is of utmost importance for their well-being and future. This includes instilling adequate education in schools about healthy eating and accessibility to sport which foster both a sense of community and improve physical and mental wellbeing.

“Ultimately, good health needs to be an easier, more accessible choice – not one that requires privilege, planning, and willpower,” D. Li concludes.

To read more research like this, access the journal Nutrients, or access the full MDPI journal list.