The effect of nocturnal 'meat' versus 'vegetarian' dinners on sleep quality and daily functioning

Sleep and nutrition are central to an organism’s continued physiological existence. Moreover, both of these functions include significant social-behavioral, educational, and cultural elements. This study examined the effects of two types of nocturnal dinners (“vegetarian” versus “meat”) on the quality and quantity of sleep, as well as on subjective sleepiness and attention levels the following morning. 20 healthy subjects (10 men and 10 women) participated in a lab polysomnography study for two non-consecutive nights at the Sleep Institute at Tel-Hai College. They completed questionnaires (Karolinska Sleepiness Scale (KSS) and Brief Symptom Inventory Questionnaire (BSI)), as well as a computerized attention and concentration test (Conner’s Continuous Performance Test-III (CPT-III)), on the mornings after each night of polysomnography. On the first night, subjects consumed a vegetarian meal made up of non-animal ingredients (vegetables and vegetable proteins). On the second night, they were given a meat meal composed of carbohydrates, fats, and animal proteins. No significant differences were measured in the various sleep parameters: efficacy, structure, and quality of sleep. There were also no significant differences found in the behavioral measures examined: subjective sleepiness (KSS), mood (BSI), and attention and concentration abilities (CPT-III). The findings of this study indicate that, contrary to popular belief, consuming a meat dinner may not affect a person’s quality of sleep, or their ability to function the morning after, differently than a vegetarian dinner. Future studies should further examine the relationship between sleep and nutrition. The clinical trial is registered under the number 0010-18ASMC.