Journal of Nutrition Research
An official journal of IAPEN India association

1 Introduction

Sleep efficiency—the ratio of total sleep time to time spent in bed—is a key determinant of physical health, cognitive performance, and emotional well-being[1]. Poor sleep quality links to impaired attention, mood disturbances, and reduced productivity[2]. While stress, screen time, and irregular schedules contribute significantly, emerging evidence points to dietary patterns, particularly evening meal composition and timing, as influential factors[3].

High-fat or high-sugar meals near bedtime can disrupt circadian rhythms, delay sleep onset, and increase awakenings[4]. Balanced meals earlier in the evening may promote better sleep continuity and next-day alertness[5]. However, qualitative insights into lived experiences remain limited, especially in diverse cultural contexts like India, where meal patterns often include spiced, carbohydrate-rich, or heavy foods.

This qualitative study explores how evening meal types and timings influence perceived sleep efficiency and next-day alertness among Indian adults aged 18-45 years.

2 Review of Literature

Dietary habits increasingly influence sleep quality and efficiency. High-fat meals, especially late at night, associate with longer sleep latency, reduced REM sleep, and fragmentation[6]. Conversely, diets rich in fruits, vegetables, and complex carbohydrates support melatonin production and sleep onset[7].

Protein from tryptophan-rich sources (e.g., dairy, legumes) enhances serotonin synthesis and sleep regulation[8]. Spicy or heavy meals may cause gastric discomfort, delaying initiation[9].

Meal timing proves critical: eating within two hours of bedtime elevates core temperature and metabolism, impairing efficiency[10]. Earlier meals link to improved next-day cognition and mood[11].

Recent studies reinforce these links. Chrononutrition research shows delayed meal timings and frequent eating correlate with poorer sleep quality[11]. High-glycemic meals may shorten onset if timed earlier (≥4 hours before bed), but late heavy meals disrupt architecture[1]. Time-restricted eating aligns with circadian rhythms, potentially enhancing sleep[12-20].

Qualitative research capturing cultural patterns in middle-income countries remains scarce, highlighting the need for in-depth exploration in Indian contexts[16].

3 Methodology

Study Design
This qualitative, cross-sectional study explored perceived effects of evening meal composition and timing on sleep efficiency and next-day alertness.

Participants
35 participants aged 18–45 years (20 females, 15 males) recruited via purposive sampling from urban and semi-urban areas. Inclusion: regular evening meals, willingness to discuss sleep. Exclusion: diagnosed sleep disorders or sleep-affecting medications.

Data Collection

In-depth, semi-structured interviews (30–45 minutes, in-person or video) covered meal composition (self-described examples), timing, perceived sleep quality (onset, interruptions, depth), and morning alertness. Participants asked about potential confounders (e.g., caffeine, screen time, stress).6 Interviews audio-recorded with consent.

Data Analysis

Transcripts analyzed using thematic analysis (inductive approach). Two researchers independently coded, identifying themes (e.g., "delayed onset from heavy meals," "refreshing sleep with balanced early dinners"). Themes refined iteratively; data saturation achieved around 30 interviews. Inter-coder agreement ensured through discussion. Meal types categorized based on participant descriptions: high-fat/heavy (e.g., fried items, rich curries), high-carbohydrate (e.g., rice-heavy, sweets), balanced (moderate protein/carbs/fats, vegetables). Prevalence noted qualitatively (e.g., "many," "most").

Ethical Considerations

Ethical approval was obtained from the Institutional Ethics Committee. Written informed consent was obtained from all participants. Identifying details were anonymized during transcription and reporting.

4 Results

Participant Characteristics

The study included 35 participants aged 18–45 years, with a median age of approximately 32 years. There were 20 females (57%) and 15 males (43%). Participants represented diverse occupational backgrounds: students comprised 34% (n=12), IT professionals 26% (n=9), healthcare workers 23% (n=8), and service employees 17% (n=6). All resided in urban or semi-urban areas, providing a varied context for exploring lifestyle influences on sleep and dietary habits.
 

Influence of Meal Composition on Sleep Efficiency

Participants frequently linked evening meal composition to their perceived sleep quality. Those who described consuming high-fat or heavy meals—such as fried foods, rich curries, or oily preparations—commonly reported negative effects on sleep. Many experienced bloating and digestive discomfort, leading to delayed sleep onset, restlessness throughout the night, and a sense of incomplete restoration. For instance, one participant noted, "After an oily dinner, I toss and turn for hours before falling asleep" (P12, male, late eater). In contrast, participants who favored balanced meals, characterized by moderate portions of protein (e.g., lentils or lean meats), low-glycemic carbohydrates, vegetables, and healthy fats, overwhelmingly described positive sleep experiences. Most in this group reported easier digestion, fewer interruptions, and deeper, more continuous sleep. A typical reflection was, "A light meal with vegetables and dal allows me to sleep deeply without waking up" (P25, female).

High-carbohydrate meals, often rice-heavy or including sweets, presented mixed outcomes. Some participants appreciated faster sleep onset, attributing it to a calming effect, with comments like "A big rice meal helps me fall asleep quickly" (P7). However, others in this category mentioned occasional early-morning awakenings or a feeling of unrest, possibly related to fluctuations in blood sugar levels.

Influence of Meal Timing on Sleep and Alertness

Meal timing emerged as a prominent theme independent of composition. Participants who consumed dinner at least two hours before bedtime generally reported superior sleep quality and next-day alertness, irrespective of the meal type. Earlier timing was associated with reduced nighttime disturbances and a smoother transition to sleep. Late dinners, particularly those after 10:00 PM, were consistently linked to poorer outcomes, including prolonged time to fall asleep, fragmented rest, and feelings of sluggishness the following morning. One participant explained, "Eating past 10 PM makes me feel sluggish and unfocused the next day, no matter what I eat" (P8).

Combined Effects of Meal Composition and Timing on Next-Day Alertness

The interaction between meal composition and timing appeared to amplify effects on both sleep efficiency and daytime functioning. The most favorable reports came from participants who combined balanced meals with earlier dinner timing. These individuals frequently described high morning energy, improved concentration, and stable mood throughout the day. A representative quote was, "Simple roti-sabzi by 8 PM leaves me waking up energetic and ready for work" (P31).

Conversely, the least favorable outcomes were observed among those consuming high-fat or heavy meals late at night. This combination was associated with pronounced morning grogginess, low energy, reduced focus, and occasional mood fluctuations. One participant shared, "Late-night fried chicken gives me heartburn and I wake up feeling tired and irritable" (P19). Although potential confounders such as stress, caffeine intake, and screen time were discussed during interviews, participants primarily attributed sleep and alertness variations to dietary patterns rather than these factors [Table. 1].

Thematic Distribution of Meal Patterns

Overall, balanced meals with earlier timing represented the most commonly reported pattern linked to positive sleep and alertness outcomes, while heavy, late-night eating was the predominant pattern among those with poorer experiences (See [Table. 2] for a descriptive thematic distribution of reported meal patterns).

5 Discussion

The findings of this qualitative study suggest that evening meal composition and timing interactively influence perceived sleep efficiency and next-day alertness in Indian adults aged 18–45 years. High-fat or heavy meals consumed late (<2 hours before bedtime) were frequently linked to digestive discomfort, delayed sleep onset, restlessness, and morning grogginess. Conversely, balanced meals eaten earlier (≥2 hours before bedtime) were associated with uninterrupted sleep and greater morning energy. High-carbohydrate meals had mixed effects: faster onset for some, but early awakenings for others, likely due to glycemic fluctuations.

These results align with chrononutrition research, where late or heavy meals disrupt circadian rhythms, elevate core temperature, and fragment sleep, while earlier balanced meals support melatonin production and sleep continuity. High-glycemic carbohydrates can aid onset if timed well but risk instability if late.

In the Indian context, where spiced or heavy late dinners are common due to lifestyles, shifting to earlier, lighter balanced meals (e.g., roti-sabzi with dal) appears culturally feasible and beneficial.

Although participants noted confounders like stress and screen time, dietary factors emerged as prominent in their experiences.

Limitations

This small-scale (n=35) qualitative study relies on self-reported data, potentially introducing bias. Objective measures (e.g., actigraphy) were absent, and generalizability is limited to urban/semi-urban adults without sleep disorders.

6 Conclusion and Future Implications

This study underscores that lighter, balanced evening meals timed earlier may serve as accessible, non-pharmacological strategies to enhance perceived sleep efficiency and next-day alertness. Promoting such habits could address prevalent sleep complaints in Indian contexts. Future research should employ larger, quantitative designs with objective sleep tracking (e.g., wearables) and detailed dietary assessments to validate these interactions. Interventional trials testing shifts to earlier balanced dinners, tailored to cultural meals, could inform personalized chrononutrition guidelines.