Acute partial sleep deprivation due to environmental noise increases weight gain by reducing energy expenditure in rodents.

OBJECTIVE: Chronic partial sleep deprivation (SD) by environmental noise exposure increases weight gain and feeding in rodents, which contrasts weight loss after acute SD by physical methods. This study tested whether acute environmental noise exposure reduced sleep and its effect on weight gain, food intake, physical activity, and energy expenditure (EE). It was hypothesized that acute exposure would (1) increase weight gain and feeding and (2) reduce sleep, physical activity, and EE (total and individual components); and (3) behavioral changes would persist throughout recovery from SD.

METHODS: Three-month old male Sprague-Dawley rats slept ad libitum, were noise exposed (12-h light cycle), and allowed to recover (36 h). Weight gain, food intake, sleep/wake, physical activity, and EE were measured.

RESULTS: Acute environmental noise exposure had no effect on feeding, increased weight gain (P < 0.01), and reduced sleep (P < 0.02), physical activity (P < 0.03), total EE (P < 0.05), and several components (P < 0.05). Reductions in EE and physical activity persisted during recovery.

CONCLUSIONS: Reductions in EE during sleep, rest, and physical activity reduce total EE and contribute to weight gain during acute SD and recovery from SD. These data emphasize the importance of increasing physical activity after SD to prevent obesity.