1.1 Background and Context

The rising prevalence of mood disorders, such as anxiety, irritability, and depression, among young adults has become a significant public health concern, with lifestyle factors increasingly implicated in mental health outcomes. Fast food consumption, characterized by high-calorie, low-nutrient diets, has surged in popularity due to its convenience and accessibility, particularly among young adults facing academic and professional pressures. Emerging evidence suggests that dietary habits influence emotional well-being, with processed foods linked to adverse psychological effects. The provided dataset, comprising responses from 35 young adults (aged 18–45), indicates frequent fast food intake (e.g., weekly or daily) is associated with negative mood outcomes like lethargy and irritability, highlighting the need to explore this relationship further.

1.2 Significance of the Study

Understanding the link between fast food consumption and mood disorders is critical, as young adults are particularly vulnerable to mental health challenges due to demanding schedules, high screen time, and disrupted sleep patterns. The dataset reveals that 60% of participants reported negative mood effects (e.g., “guilt,” “mood swings”) tied to fast food, while 80% of those who reduced intake noted improved mood and energy. These findings suggest that dietary interventions could mitigate mood disorders, especially for high-risk groups like students in fields such as neuroscience and medicine. This study addresses the urgent need for evidence-based insights to inform public health strategies targeting both nutritional and mental well-being.

1.3 Research Gap

Despite growing research on diet and mental health, few studies have employed qualitative methods to explore the subjective experiences of young adults regarding fast food consumption and its emotional impacts. Existing literature often focuses on quantitative measures of nutrient intake or clinical diagnoses, overlooking the lived experiences of diverse populations. The dataset’s in-depth interviews provide rich qualitative data on mood descriptors (e.g., “lethargic, bloated” or “more energetic”) and contextual factors like screen time and sleep, offering a unique opportunity to address this gap by examining how young adults perceive and articulate the effects of fast food on their mental health.

1.4 Study Objectives

This study aims to investigate the relationship between fast food intake and mood disorders among young adults through semi-structured, in-depth interviews. Specific objectives include: (1) assessing the frequency of fast food consumption and its association with negative mood outcomes, (2) exploring the impact of reducing fast food intake on emotional well-being, and (3) examining the role of confounding factors such as screen time and sleep quality. By analyzing qualitative data from a diverse sample of 35 participants, the study seeks to provide nuanced insights into dietary influences on emotional well-being and inform targeted interventions for young adults.

1.5 Review of Literature

2.1 Study Design

This study utilized a qualitative research design to explore the relationship between fast food consumption and mood disorders among young adults. Semi-structured, in-depth interviews were employed to capture detailed, nuanced insights into participants’ dietary habits, mood experiences, and related lifestyle factors. The qualitative approach was chosen to explore subjective perceptions and contextual influences, such as screen time and sleep quality, which were critical to understanding the multifaceted nature of mood disorders in the context of fast-food intake.

2.2 Study Duration

The study was conducted over a period of four weeks, from 25 April to 25 May 2025. Data collection was completed within this timeframe through scheduled one-on-one interviews, either in person or via virtual platforms depending on participant availability.

2.3 Participant Selection

2.4 Data Collection

Data were gathered through one-on-one, semi-structured interviews conducted either in person or virtually, depending on participant availability. A standardized questionnaire guided the interviews, focusing on key variables: fast food consumption frequency (G14_FastFood_Frequency), immediate and long-term mood effects (G15_FastFood_AfterEffect, C6_SleepEmotionsDecisions), outcomes of reducing fast food intake (G16_FastFood_ChangeEffect), and contextual factors such as screen time (B2_DigitalEffect) and sleep patterns (C4_SleepRoutine, C5_SleepAffectingFactors). Interviews lasted approximately 30–45 minutes, were audio-recorded with participant consent, and transcribed verbatim to ensure accuracy. The open-ended nature of the questions allowed participants to provide detailed responses, such as describing mood outcomes like “lethargy” or “improved focus.”

2.5 Categorization of Fast Food Consumption

Fast food intake was categorized based on frequency:

• Low: Rare or 1–2 times/month

• Average: 1–3 times/week

• High: ≥3–4 times/week or daily. These categories were based on participant responses (G14_FastFood_Frequency).

2.6 Data Analysis

Thematic analysis was employed to identify patterns and themes within the qualitative data. Responses were coded for mood sentiment (positive, negative, neutral) based on keywords (e.g., “irritable,” “energetic”) and categorized by fast food consumption frequency (e.g., rarely, weekly, daily). Data cleaning involved standardizing text (e.g., trimming spaces, unifying terms like “1-2 times/month”), handling missing entries, and ensuring consistency across responses. Two researchers independently coded the data to enhance reliability, with discrepancies resolved through discussion. Validity was further ensured through member checking, where participants reviewed summaries of their responses to confirm accuracy. The analysis focused on linking fast food intake to mood outcomes while exploring the influence of confounding factors like screen time and sleep disturbances.

Participants typically reported mood effects within hours to a day after fast food consumption. For those who reduced intake, mood improvements were reported within one to four weeks, though this was based on recall and not measured prospectively. A detailed dietary recall chart was not used. Participants were asked open-ended questions about their usual fast food frequency and recent eating behavior.

2.7 Ethical Considerations

Ethical approval was obtained from the Institutional Ethics Committee of Datta Meghe Institute of Higher Education & Research (Ref. No: DMIHER(DU)/IEC/2025/795). Written informed consent was collected from all participants before data collection began. Confidentiality and anonymity were maintained throughout the research process using pseudonyms during transcription and reporting.

3.1 Fast Food Consumption Frequency

Thematic analysis revealed varied patterns of fast food consumption among the 35 participants (aged 18–45). Approximately 31% (11 participants) reported consuming fast food rarely or 1–2 times per month, 40% (14 participants) consumed it weekly (1–3 times per week), and 29% (10 participants) reported frequent consumption (3–4 times per week or daily). Students, particularly those in high-stress fields like neuroscience, medicine, and data science (e.g., participants 6, 8, 9, 18, 30), were overrepresented in the frequent consumption group, citing convenience and academic pressures as key drivers.

Figure 1 visualizes the distribution of fast-food consumption frequency, showing that weekly consumption (14 participants) is the most common, followed by rare (11) and frequent (10) consumption.

3.2 Mood Effects of Fast Food Intake

Over 60% of participants (21 out of 35) reported negative mood outcomes associated with fast food consumption, particularly those consuming fast food weekly or more frequently. Common descriptors included “lethargy” (e.g., participants 4, 6, 7, 8), “irritability” (e.g., participants 6, 7, 9, 15), “guilt” (e.g., participants 9, 24, 30), and “mood swings” (e.g., participants 7, 27). For example, participant 6 (M.Sc. Neuroscience, twice a week) noted feeling “lethargic, bloated, mood drop” after fast food, while participant 4 (doctor, daily) reported “weakness, lethargy, no mood.” Positive or neutral mood effects were less common, reported by only 14% (5 participants), typically those with rare consumption (e.g., participant 11: “quick and tasty”).

3.3 Impact of Reducing Fast Food Intake

Of the 25 participants who reported reducing fast food intake (G16_FastFood_ChangeEffect = “Yes” or implied improvement), 80% (20 participants) described positive changes in mood and energy. Common themes included “more energetic” (e.g., participants 7, 8, 12), “better focus” (e.g., participants 9, 18, 33), and “lighter” or “improved mood” (e.g., participants 1, 6, 19). For instance, participant 8 (B.Sc. Neuroscience) noted feeling “more alert with home food,” and participant 19 (hematologist) reported “clarity” with reduced fast food. Participants who did not reduce intake or reported no change (10 participants) often cited persistent negative moods or no significant effects.

3.4 Influence of Contextual Factors

Negative mood outcomes were frequently compounded by high screen time and poor sleep quality. Participants with frequent fast food consumption (weekly or daily) often reported high screen time (6–16 hours daily, e.g., participants 4, 18, 23, 35) and described sleep disturbances linked to “stress” or “late screens” (e.g., participants 6, 24, 30). For example, participant 35 (data analyst, 13–14 hours screen time) reported “screen fatigue, stress, irritability” alongside frequent fast food intake, while participant 24 (software developer) noted “impatient, distracted” moods tied to both diet and screen use. Thematic analysis suggested that these factors amplified negative mood effects, particularly among students and professionals with demanding schedules.

3.5 Notable Observations

A notable finding was the pronounced impact on students in high-stress academic fields (e.g., neuroscience, medicine, data science), who comprised 60% of the frequent fast food consumers (6 out of 10). These participants (e.g., 6, 8, 9, 30) consistently reported negative mood outcomes, potentially exacerbated by academic stress and reliance on convenience foods. Additionally, younger participants (aged 20–30) showed a higher prevalence of negative mood effects (15 out of 21 negative reports) compared to older participants (31–44), suggesting age-related lifestyle differences.