According to the researchers, Hong Kong’s numbers are well above the global averages of 34% for depressive symptoms and 31% for anxiety symptoms.
These mental health issues carry a high degree of comorbidity and place substantial burdens on individuals and society, influencing daily personal and professional functioning. This impact translates to reduced quality of life, higher healthcare costs, and diminished productivity.
Factors influencing young adults’ mental health
The rise in mental health disorders among young adults in Hong Kong can be attributed to genetic, psychological, biological, and environmental influences. Studies have highlighted several associated lifestyle factors, such as gender, body mass index (BMI), physical activity, sleep quality, screen time, household income, and substance use.
Dietary habits have also emerged as a significant factor, with growing evidence connecting high-fat, high-sugar diets to depressive and anxiety symptoms.
For example, one meta-analysis of randomized trials showed that diets low in fat and sugar but high in fibre and nutrient-dense foods could reduce depressive symptoms and improve nutritional health. Other findings have linked balanced diets rich in vegetables, fruits, whole grains, and lean proteins to lower levels of anxiety symptoms.
Specific fast-food items impact on mental health risks in young HK adults
In Hong Kong’s high-density, high-stress environment, financial and time constraints often lead young adults to prioritize low-cost, filling foods over nutrient-dense options, increasing their reliance on fast food.
Based on the aforementioned research, this trend raises specific mental health concerns. However, current studies have focused largely on overall fast food intake without examining the effects of individual fast food items.
Recognising this gap, researchers at the HKU School of Professional and Continuing Education and Hong Kong University sought to investigate how different types of fast food might influence mental health outcomes among young adults.
Given the city’s high poverty rate and small living spaces, many young residents experience food insecurity. This often leads them to opt for fast foods, which are typically cheaper and more easily accessible than other food options, to manage hunger.
Conducted on 142 individuals aged 18 to 27, the study used a food frequency questionnaire to assess the intake of 22 fast food items. Participants were divided into high- and low-intake groups based on their fast food consumption frequency.
Subsequently, it found that individuals in the high-frequency group were more likely to report symptoms of depression and anxiety than those in the low-frequency group. Notably, foods high in fat, sugar and sodium were linked to a higher occurrence of mental health symptoms. This was especially so in the case of beef burgers, fries, fried chicken, and bubble tea.
Potential protective benefits of sugar-free beverages
The study also suggested a potential protective mental health benefit associated with sugar-free beverages. Specifically, sugar-free tea consumption was correlated with a reduced risk of depressive symptoms, aligning with previous studies linking tea intake to mental health benefits.
However, the researchers noted that while tea drinking in Hong Kong generally involved unsweetened tea, additional research was necessary to confirm if sugar-free tea consistently benefited mental health outcomes.
Underlying mechanisms and broader implications
The study’s authors hypothesized that the association between high-fat, high-sugar foods and mental health issues could be due to nutritional imbalances. Fast food typically contains higher levels of saturated fat and added sugars, which may lead to deficiencies in omega-3 fatty acids, fibre, and essential vitamins.
Additionally, over-consumption of these foods can increase inflammation in the body, potentially impacting neurotransmitter production and brain health — factors linked to mental health disorders. The study further stated that increased oxidative stress and gut health issues from poor diet choices could further contribute to depressive and anxiety symptoms.
The implications for public health are notable, particularly as fast food consumption becomes more prevalent globally. While fast food may offers a quick and affordable meal option, its nutritional impact on young adults' mental health may necessitate broader dietary guidelines or targeted public health campaigns to raise awareness of these risks.
Limitations and call for further research
While the findings pointed to a potential risk of high fast food intake on mental health, the authors cautioned that the study’s cross-sectional design prevented them from establishing causality. Other limitations included the study’s small sample size, reliance on self-reported dietary habits, and lack of randomized sampling, which may have introduced recall and selection biases.
As such, they recommended future studies with a longitudinal design and larger sample sizes to validate these results and clarify the causal relationship between specific fast food items and mental health symptoms.
Notably, the study adds to a growing body of evidence linking diet and mental health, suggesting that young adults may benefit from dietary interventions that limit foods high in fat and sugar. Further exploration of these dietary impacts could support mental health management strategies that include reducing fast food intake among vulnerable populations.
Source: Nutrients
“Association of Fast-Food Intake with Depressive and Anxiety Symptoms among Young Adults: A Pilot Study”
https://doi.org/10.3390/nu16193317
Authors: Wai-kin Tang, et al.
