title: Metabolic response to short-term 4-day energy restriction in a controlled study.
abstract: OBJECTIVE
  Metabolic rate is affected not solely by diet but also by environmental characteristics such as climate and seasonal changes in day length. In the present study, we conducted a controlled study in which we observed metabolic response to short-term energy restriction (ER).
  
  
  METHODS
  Thirty-two subjects were divided randomly into a slight ER group and a moderate ER group. The energy intake per day for slight ER vs moderate ER was 1462 kcal vs 1114 kcal. During the 4-day study periods, the same daily timetable, which consists of nutrition, exercise, sleeping and others, was imposed on both groups. The same environment was also provided to both groups.
  
  
  RESULTS
  After the 4-day ER, significant decreases in body weight and basal metabolic rate (BMR) were shown in both groups. The decrease in body weight was 2% of the baseline level in both groups, and the decreases in the BMR were 6% of baseline levels in the slight ER group and 13% in the moderate ER group. The decrease in BMR in the moderate ER group was significantly larger than that in the slight ER group.
  
  
  CONCLUSIONS
  In a controlled study of short-term ER, we observed a significant decrease in BMR. There was a positive association between the degree of ER and the reduction in BMR. Reductions in BMR were greater than those in body weight. It, thus, appears that the minimization of weight loss is due to dramatic decreases in BMR. This suggests the existence of metabolic resistance against ER.
authors: Department of Hygiene, Kansai Medical University, 10-15 Fumizono-cho, 570-8506, Moriguchi, Osaka, Moriguchi, Japan, koudak@takii.kmu.ac.jp.
authors: Katsuyasu
authors: K
authors: Kouda
authors: Harunobu
authors: H
authors: Nakamura
authors: Hirao
authors: H
authors: Kohno
authors: Toyoko
authors: T
authors: Okuda
authors: Yuko
authors: Y
authors: Higashine
authors: Keiji
authors: K
authors: Hisamori
authors: Hiroyasu
authors: H
authors: Ishihara
authors: Rikio
authors: R
authors: Tokunaga
authors: Yoshiaki
authors: Y
authors: Sonoda