Human behaviour has changed enormously across the short span of several generations. Computers, smartphones, tablets, television—we now spend an inordinate amount of time looking at screens.

Recent data shows that the global average screen time for people aged between 16 and 64 in 2023 was 6 hours 37 minutes per day. This equates to around 44% of our waking hours.

It is thus no wonder that, in light of recent research, many people’s New Year’s resolutions are now focused on limiting time spent on their devices.

Here, we’ll take a look at what research says about screen time and how to successfully limit it in 2024.

How does screen time affect the brain?

The widespread consumption of digital media and use of LED screens has many implications for public health. Having spent hundreds of thousands of years without them, and in the space of less than a century, most humans now spend a large amount of time every day looking at screens.

This technology is so deeply embedded in our culture that one can no longer generally get by without some kind of computer. We use them for employment, education, and entertainment. As such a recent shift in our behaviour, there’s relatively little longitudinal data showing us how this looks in the brain.

Much evidence is emerging, however, that suggests that this new behaviour may impose some structural changes in the brain. Children especially require diverse experiences for healthy development, to strengthen many different neuronal pathways. Much of what we experience through a screen provides “impoverished” stimulation—as there is little variation in the stimuli, the brain isn’t forging new neuronal pathways.

This can lead to digital addiction—a compulsive need to use digital devices. One MDPI review study notes that the most vulnerable region of the brain to digital addiction is the prefrontal cortex, which is responsible for regulating our emotions, thought processes, and actions, as well as impulse control and decision making.

Other regions affected are “the brain’s cortex (frontal, parietal, temporal, and occipital lobes), cerebellum, and subcortical structures, such as the basal ganglia (containing the striatum and nucleus accumbens), the thalamus, and the hippocampus”. Interference with these affects many cognitive functions.

The effects of so many neural networks being disrupted can lead to significant consequences for our health.

How does screen time affect mental and physical health?

It is quite complicated to accurately measure the effect of extensive screen use on our health. The effects vary depending on the content consumed, personality type, etc. However, there are many significant findings based on the consumption of specific media.

Mental health

Despite ostensibly making us more connected, social media actually often increases feelings of isolation, leading to depression and anxiety. It also increases the risk of developing eating disorders and addictions.

A positive relationship has also been demonstrated between media exposure and body dissatisfaction in one MDPI study. This was also related to disordered eating behaviours (such as binge eating, using diet pills, etc.). Total screen time was associated with greater odds of trying to lose weight, as well as cosmetic surgery intention.

Another study presents a meta-analysis that outlines the prevalence of depression, anxiety, sleep difficulties, bullying, and isolation amongst users. But, the authors point out that social media can help as well as hinder one’s mental health. It can also be an effective medium for intervention, targeting at-risk users and implementing preventative measures.

Physical health

Research shows that excessive screen time is associated with an increased risk of obesity and other cardiometabolic risk factors in children, due to increased sedentary behaviour. However, this is still not fully understood. It may also be due to screen time influencing satiation signals and food intake control, as well as ad viewing. Additionally, higher screen time is associated with decreased physical activity.

Sleep is also a huge cornerstone of physical wellness that screen time impacts upon. The mental stimulation can make it harder for the brain to calm down for bed. It can also mean that it is harder to put down our phones, due to our brain’s reward system being activated. This results in a later bedtime. Also, there is evidence suggesting that blue light interferes with the production of melatonin, a chemical that regulates our sleep–wake cycle.

How can I reduce my screen time?

Reducing your screen time in the new year requires a little bit of planning. Here, we’ll go over a few ways in which you can start to make changes to your digital habits.

Monitor screen time

First, you need to know how long you’re spending looking at screens and whether you need to improve your habits. There are many apps that will track and report your screen time statistics to you. Many people struggle to accurately quantify how long they are spending at a screen across their various devices. By setting up each device to feed back screen time data, you can assess your screen time habits objectively and act accordingly.

Create a digital schedule

The next step is to organise your time. Time blocking—setting yourself windows of time to work on just one thing—is a proven way to improve time management. Allowing yourself certain periods of the day to look at and scheduling breaks away from the screen will help you take control of your digital habits. Some research suggests that adults should spend less than 2 hours per day on a screen outside of work.

Also, setting a digital curfew—a time in the evening after which you don’t look at any screen—and limiting screen time in the bedroom will help ensure that screen time isn’t affecting your sleep.

Practise mindfulness and exercise

As discussed above, screen time is intimately linked with our mental and physical health. Ensuring that you’re taking steps to reduce stress and embrace offline environments, as well as keeping physically fit, will help prevent any negative consequences from screen usage. On top of a digital schedule, set and stick to a schedule of exercise and offline activities. Read more on decreasing stress through mindfulness here.

Research in 2024

Digital devices are now prevalent in our lives. However, there is still much we don’t know about the effects of extensive usage. As we gather more data, the true extent to which screen time impacts our health will be revealed.

MDPI will continue to publish high-quality research on screen time and its impact on our health in 2024. Make sure to look at journals such as IJERPH, Children, MTI, and many more to keep up to date with cutting-edge research on this topic.

Additionally, read more on the MDPI blog about keeping your New Year’s Resolutions.