Objective Food Intake in Night and Day Shift Workers: A Laboratory Study

Area of Science:

• Occupational Health
• Nutritional Science
• Chronobiology

Background:

• Night shift work is associated with increased risk of overweight and obesity.
• Short sleep duration and circadian misalignment in night shift workers may alter food intake regulation, leading to weight gain.
• Previous studies on shift worker food intake relied on subjective self-reports, lacking objective dietary assessment.

Purpose of the Study:

• To objectively examine the impact of night shift work on food intake and choice in real-life shift workers.
• To compare food intake patterns between female day and night shift workers using objective measures.

Main Methods:

• 12 female day and 12 night shift hospital workers participated in a laboratory-based assessment.
• Participants consumed an ad libitum test meal after awakening from sleep following their final work shift.
• Sleep duration was objectively measured using wrist-accelerometry.

Main Results:

• Sleep duration was significantly longer in day workers compared to night workers (373.9 vs. 260.6 min).
• No significant difference was found in total calories consumed between groups (943.1 vs. 878.6 kcal).
• Day workers consumed a higher percentage of protein in their diet compared to night workers (16.0% vs. 11.8%).

Conclusions:

• This is the first study to objectively assess food intake in actual night and day shift workers.
• Night shift workers consumed less protein, which may be a contributing factor to their increased risk of overweight and obesity.
• Lower protein intake could impact satiety, potentially influencing energy balance and weight gain in shift workers.