title: Nocturnal eating disturbs phosphorus excretion in young subjects: a randomized crossover trial.
abstract: BACKGROUND
  Nocturnal eating have recently increased. Serum phosphorus levels and regulators of phosphorus have circadian variations, so it is suggested that the timing of eating may be important in controlling serum phosphorus levels. However, there have been no reports on the effects of nocturnal eating on phosphorus metabolism. The objective was to evaluate the effects of nocturnal eating on phosphorus metabolism.
  
  
  METHODS
  Fourteen healthy men participated in two experimental protocols with differing dinner times. The design of this study was a crossover study. The subjects were served test meals three times (breakfast; 07:30 h, lunch; 12:30 h, dinner; 17:30 or 22:30 h) a day. Blood and urine samples were collected to assess diurnal variation until the following morning.
  
  
  RESULTS
  The following morning, fasting serum phosphorus levels in the late dinner group were markedly higher than those in the early dinner group (p < 0.001), although serum calcium levels were maintained at approximately constant levels throughout the day in both groups. Fluctuations in urinary calcium excretion were synchronized with the timing of dinner eating, however, fluctuations in urinary phosphorus excretion were not synchronized. Urinary phosphorus excretions at night were inhibited in the late dinner group. In the late dinner group, intact parathyroid hormone levels didn't decrease, and they were significantly higher in this group compared with the early dinner group at 20:00 h (p = 0.004). The following morning, fasting serum fibroblast growth factor 23 levels in the late dinner group had not changed, but those in the early dinner group were significantly increased (p = 0.003). Serum free fatty acid levels before dinner were significantly higher in the late dinner group compared with the early dinner group.
  
  
  CONCLUSIONS
  Our results indicate that nocturnal eating inhibits phosphorus excretion. It is suggested that nocturnal eating should be abstained from to manage serum phosphorus levels to within an adequate range.
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan. sakuma@u-shizuoka-ken.ac.jp.
authors.forename: Masae
authors.initials: M
authors.lastname: Sakuma
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Saaya
authors.initials: S
authors.lastname: Noda
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Yuuka
authors.initials: Y
authors.lastname: Morimoto
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Akitsu
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Kanaho
authors.initials: K
authors.lastname: Nishino
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Sakiko
authors.initials: S
authors.lastname: Ando
authors.affiliation: School of Nursing Sciences, The University of Shizuoka, Shizuoka, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Umeda
authors.affiliation: School of Nursing Sciences, The University of Shizuoka, Shizuoka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ishikawa
authors.affiliation: Laboratory of Clinical Nutrition and Management, Graduate School of Nutritional and Environmental Sciences, The University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Arai
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D005247:Feeding Behavior; D006801:Humans; D008297:Male; D010758:Phosphorus / Q000097:blood* / Q000652:urine*; D055815:Young Adult
chemical_list: D010758:Phosphorus