Anxiety in teenagers linked to sugary drinks – new research

Anxiety affects an estimated one in five teenagers. The condition can seriously affect their social lives, school performance and overall wellbeing. And, worryingly, anxiety disorders that begin during adolescence often continue into adulthood.

Biological, genetic and environmental factors are all known to play a role in a person’s likelihood of developing anxiety. But a growing body of research suggests that diet may also influence mental health.

Some foods, such as fruits and vegetables and omega-3 fatty acids, have been linked to lower anxiety symptoms.

On the other hand, diets high in free sugar have been linked to poorer mental health in adolescents. Free sugars include sugar added to foods and drinks, as well as those normally present in honey, syrups and fruit and vegetable juices.

UK guidelines recommend that free sugars make up no more than 5% of our daily calorie intake. Adolescents typically consume the most free sugar of any age group, sometimes up to 20% of their daily total energy intake – much of it coming from sugary drinks.

Now, my colleagues and I have published new research showing that sugary drink consumption may be linked to higher levels of anxiety in adolescents.

This review combined data from several previous studies looking at the amount of sugary drink teenagers consume and how anxious they feel. Our research group pulled together findings from multiple studies published between 2000 and 2025. Of the nine studies included, seven found a clear link between sugary drink intake and anxiety.

The studies involved young people aged ten to 19. Sugary drink intake was usually measured through surveys. Sugary drinks included fizzy drinks, colas, sweetened fruit juices, sweetened milk drinks, energy drinks and sweetened tea or coffee.

The results of the study showed a significant positive association: teenagers who consumed high amounts of sugary drinks had 34% higher odds of being diagnosed with an anxiety disorder.

It’s important to remember that the included studies were observational. This means they can show patterns or associations, but they do not indicate that sugary drinks cause anxiety. It’s also possible that anxiety leads teenagers to consume more sugary drinks.

Other factors, such as education levels and family income, are known to influence both mental health and sugary drink intake.

The gut-brain axis, which is the network that links your brain to your gut, could also play a role in the connection between sugary drink consumption and anxiety. However, there are many things that affect gut health as well, including overall diet, stress levels and sleep – all of which have also been linked to anxiety.

Overall, our study suggests that reducing sugary drink consumption could be a helpful way to support adolescent mental health. While numerous studies have investigated the impact reducing sugary drink intake has on the physical health of adolescents, there is a need now to investigate whether this also has mental health benefits.

Reducing sugary drink intake

UK dietary guidelines recommend that adolescents and adults consume no more than 30 grams of sugar per day (approximately seven teaspoons). Given that a single can of fizzy drink can contain around 35 grams of sugar, cutting back on sugary drinks is an effective way to stay within this limit.

There are other practical ways of reducing intake of sugary drinks. This includes drinking sparkling or soda water with a slice of lemon, cucumber, berries or mint to get natural flavour without added sugar. Sugary drinks can be replaced with water, milk or sugar-free alternatives.

Another option is to switch to low-calorie, artificially-sweetened drinks (though these should only be consumed in moderation). Energy drinks can have a negative effect on sleep quality, academic performance and behaviour in adolescents so it’s a good idea to replace these with alternatives that contain less caffeine, such as tea or coffee.

With growing concerns about anxiety in teenagers, it’s becoming increasingly important to identify whether changing certain lifestyle factors can help reduce their risk of experiencing poor mental health. Although we still don’t fully understand how sugary drinks might influence anxiety, this study suggests they could play a role.

Chloe Casey does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.