***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background / objectives : The extent to which alterations in energy expenditure ( EE ) in response to sleep restriction contribute to the short sleep – obesity relationship is not clearly defined . Short sleep may induce changes in resting metabolic rate ( RMR ) , thermic effect of food ( TEF ) and postpr and ial substrate oxidation . Subjects/ methods : Ten females ( age and body mass index : 22–43 years and 23.4–28 kg m−2 ) completed a r and omized , crossover study assessing the effects of short ( 4 h per night ) and habitual ( 8 h per night ) sleep duration on fasting and postpr and ial RMR and respiratory quotient ( RQ ) . Measurements were taken after three nights using whole-room indirect calorimetry . The TEF was assessed over a 6-h period following consumption of a high-fat liquid meal . Results : Short versus habitual sleep did not affect RMR ( 1.01±0.05 and 0.97±0.04 kcal min−1 ; P=0.23 ) . Fasting RQ was significantly lower after short versus habitual sleep ( 0.84±0.01 and 0.88±0.01 ; P=0.028 ) . Postpr and ial EE ( short : 1.13±0.04 and habitual : 1.10±0.04 , P=0.09 ) and RQ ( short : 0.88±0.01 and habitual : 0.88±0.01 , P=0.50 ) after the high-fat meal were not different between conditions . TEF was similar between conditions ( 0.24±0.02 kcal min−1 in both ; P=0.98 ) , as was the ∼6-h incremental area under the curve ( 1.16±0.10 and 1.17±0.09 kcal min−1 × 356 min after short and habitual sleep , respectively ; P=0.92 ) . Conclusions : Current findings observed in non-obese healthy premenopausal women do not support the hypothesis that alterations in TEF and postpr and ial substrate oxidation are major contributors to the higher rate of obesity observed in short sleepers . In exploring a role of sleep duration on EE , research should focus on potential alterations in physical activity to explain the increased obesity risk in  short sleepers BACKGROUND Acute partial sleep deprivation increases plasma concentrations of ghrelin and decreases those of leptin . OBJECTIVE The objective was to observe modifications in energy intake and physical activity after  acute partial sleep deprivation in healthy men . DESIGN Twelve men [ age : 22 + /- 3 y ; body mass index ( in kg/m(2 ) ) : 22.30 + /- 1.83 ] completed a r and omized 2-condition crossover study . During the first night of each 48-h session , subjects had either approximately 8 h ( from midnight to 0800 ) or approximately 4 h ( from 0200 to 0600 ) of sleep . All foods consumed subsequently ( jam on buttered toast for breakfast , buffet for lunch , and a free menu for dinner ) were eaten ad libitum .  Physical activity  was recorded by an actimeter .  Feelings of hunger , perceived pleasantness of the foods , desire to eat some foods , and sensation of sleepiness were also evaluated . RESULTS In comparison with the 8-h sleep session , subjects consumed 559 + /- 617 kcal ( ie , 22 % ) more energy on the day after sleep restriction ( P < 0.01 ) , and prepr and ial hunger was higher before breakfast ( P < 0.001 ) and dinner ( P < 0.05 ) . No change in the perceived pleasantness of the foods or in the desire to eat the foods was observed . Physical activity from 1215 to 2015 was higher after sleep restriction than after 8 h of sleep ( P < 0.01 ) , even though the sensation of sleepiness was more marked ( P < 0.01 ) . CONCLUSIONS One night of reduced sleep subsequently increased food intake and , to a lesser extent , estimated physical activity-related energy expenditure in healthy men . These experimental results , if confirmed by long-term energy balance measurements , suggest that sleep restriction could be a factor that promotes obesity . This trial was registered at clinical trials.gov as NCT00986492 Objective : The purpose of this study was to determine if overnight energy expenditure , the lowest energy expenditure sustained for 60 min during the night , measured and predicted basal metabolic rate are equivalent . Design : Overnight energy expenditure ( ON-EE ) , the lowest energy expenditure sustained for 60 min during sleep ( LS-EE ) and basal metabolic rate ( BMR ) were measured two to seven times in a room-sized indirect calorimeter in 69 adult subjects . Subjects ’ gender , age , weight and height were also used to predict BMR ( FAO/WHO/UNU , 1985 ) ( BMR-WHO ) . Setting : Beltsville Human Nutrition Research Center , Beltsville , MD , USA . Results : The results from calorimetry measurements ( mean±s.d . ) included : ON-EE ( 6.87±0.99 MJ/d ) , LS-EE ( 6.18±0.94 MJ/d ) and BMR ( 6.87±0.99 MJ/d ) . Predicted BMR mean was : BMR-WHO , 6.95±1.03 . The mean within-subject difference for the calorimetry measurements were : ON-EE , 0.21 MJ/d ; LS-EE , 0.16 MJ/d ; and BMR , 0.34 MJ/d . Results indicate there was no significant difference between ON-EE , BMR and BMR-WHO . LS-EE was significantly lower ( P<0.0001 ) than ON-EE , BMR and BMR-WHO . Conclusion : These results indicate that while metabolic rate drops significantly below BMR during sleep , overnight metabolic rate and BMR are equivalent . Sponsorship : US Department of Agriculture , Agricultural Research Service BACKGROUND Epidemiologic evidence shows an increase in obesity concurrent with a reduction in average sleep duration among Americans . Although clinical studies propose that restricted sleep affects hormones related to appetite , neuronal activity in response to food stimuli after restricted and habitual sleep has not been investigated . OBJECTIVE The objective of this study was to determine the effects of partial sleep restriction on neuronal activation in response to food stimuli . DESIGN Thirty healthy , normal-weight [ BMI ( in kg/m² ) : 22 - 26 ] men and women were recruited ( 26 completed ) to participate in a 2-phase inpatient crossover study in which they spent either 4 h/night ( restricted sleep ) or 9 h/night ( habitual sleep ) in bed . Each phase lasted 6 d , and functional magnetic resonance imaging was performed in the fasted state on day 6 . RESULTS Overall neuronal activity in response to food stimuli was greater after restricted sleep than after habitual sleep . In addition , a relative increase in brain activity in areas associated with reward , including the putamen , nucleus accumbens , thalamus , insula , and prefrontal cortex in response to food stimuli , was observed . CONCLUSION The findings of this study link restricted sleep and susceptibility to food stimuli and are consistent with the notion that reduced sleep may lead to greater propensity to overeat BACKGROUND A short sleep ( SS ) duration has been linked to obesity in observational studies . However , experimental evidence of the potential mechanisms of sleep restriction on energy balance is conflicting and , to our knowledge , nonexistent in adolescents . OBJECTIVE We investigated the effects of 3 consecutive nights of partial sleep deprivation on components of energy balance . DESIGN In a r and omized , crossover design , 21 healthy , normal-weight male adolescents ( mean ± SD age : 16.8 ± 1.3 y ) completed the following 2 experimental conditions , each for 3 consecutive nights : an SS ( 4 h/night ) and a long sleep ( LS ; 9 h/night ) duration . Endpoints were 24-h energy expenditure ( EE ) , spontaneous physical activity ( SPA ) , postintervention diet-induced thermogenesis ( DIT ) , appetite sensations , ad libitum energy intake ( EI ) , and profiles of plasma ghrelin and leptin . RESULTS The 24-h EE on day 3 was 370 ± 496 kJ higher in the SS condition than in the LS condition ( P = 0.003 ) . This difference in EE was explained by prolonged wakefulness in the SS condition and a 19 % higher SPA ( P = 0.003 ) . In a postintervention breakfast-meal challenge , there was a 0.19-kJ/min smaller incremental AUC in DIT over 4 h in the SS condition than in the LS condition ( P = 0.012 ) with no time × condition effect ( P = 0.29 ) . Subjects consumed 13 % less energy in the ad libitum meal in the SS condition ( P = 0.031 ) , with a concomitant decreased motivation to eat . Concentrations of ghrelin and leptin remained unchanged with sleep restriction . CONCLUSION Short-term sleep restriction in male adolescents is associated with a small negative energy balance driven by increased EE from prolonged wakefulness and a concomitant decreased EI and motivation to eat . This trial was registered at clinical trials.gov as NCT01198431 BACKGROUND Short sleep is associated with obesity and may alter the endocrine regulation of hunger and appetite . OBJECTIVE We tested the hypothesis that the curtailment of human sleep could promote excessive energy intake . DESIGN Eleven healthy volunteers [ 5 women , 6 men ; mean + /- SD age : 39 + /- 5 y ; mean + /- SD body mass index ( in kg/m(2 ) ) : 26.5 + /- 1.5 ] completed in r and om order two 14-d stays in a sleep laboratory with ad libitum access to palatable food and 5.5-h or 8.5-h bedtimes . The primary endpoints were calories from meals and snacks consumed during each bedtime condition . Additional measures included total energy expenditure and 24-h profiles of serum leptin and ghrelin . RESULTS Sleep was reduced by 122 + /- 25 min per night during the 5.5-h bedtime condition . Although meal intake remained similar ( P = 0.51 ) , sleep restriction was accompanied by increased consumption of calories from snacks ( 1087 + /- 541 compared with 866 + /- 365 kcal/d ; P = 0.026 ) , with higher carbohydrate content ( 65 % compared with 61 % ; P = 0.04 ) , particularly during the period from 1900 to 0700 . These changes were not associated with a significant increase in energy expenditure ( 2526 + /- 537 and 2390 + /- 369 kcal/d during the 5.5-h and 8.5-h bedtime periods , respectively ; P = 0.58 ) , and we found no significant differences in serum leptin and ghrelin between the 2 sleep conditions . CONCLUSIONS Recurrent bedtime restriction can modify the amount , composition , and distribution of human food intake , and sleeping short hours in an obesity-promoting environment may facilitate the excessive consumption of energy from snacks but not meals BACKGROUND Evidence suggests a relation between short sleep duration and obesity . OBJECTIVE We assessed energy balance during periods of short and habitual sleep in normal-weight men and women . DESIGN Fifteen men and 15 women aged 30 - 49 y with a body mass index ( in kg/m(2 ) ) of 22 - 26 , who regularly slept 7 - 9 h/night , were recruited to participate in this crossover inpatient study . All participants were studied under short ( 4 h/night ) and habitual ( 9 h/night ) sleep conditions , in r and om order , for 5 nights each . Food intake was measured on day 5 , and energy expenditure was measured with the doubly labeled water method over each period . RESULTS Participants consumed more energy on day 5 during short sleep ( 2813.6 ± 593.0 kcal ) than during habitual sleep ( 2517.7 ± 593.0 kcal ; P = 0.023 ) . This effect was mostly due to increased consumption of fat ( 20.7 ± 37.4 g ; P = 0.01 ) , notably saturated fat ( 8.7 ± 20.4 g ; P = 0.038 ) , during short sleep . Resting metabolic rate ( short sleep : 1455.4 ± 129.0 kcal/d ; habitual sleep : 1486.5 ± 129.5 kcal/d ; P = 0.136 ) and total energy expenditure ( short sleep : 2589.2 ± 526.5 kcal/d ; habitual sleep : 2611.1 ± 529.0 kcal/d ; P = 0.832 ) did not differ significantly between sleep phases . CONCLUSIONS Our data show that a reduction in sleep increases energy and fat intakes , which may explain the associations observed between sleep and obesity . If sustained , as observed , and not compensated by increased energy expenditure , the dietary intakes of individuals undergoing short sleep predispose to obesity . This trial is registered at clinical trials.gov as NCT009354 
    Output:
    
We found no significant change in total EE or resting metabolic rate as a result of PSD .
The observed increase in EI was accompanied by significantly higher fat and lower protein intakes , but no effect on carbohydrate intake .
Conclusions : The pooled effects of the studies with extractable data indicated that PSD result ed in increased EI with no effect on EE , leading to a net positive energy balance , which in the long term may contribute to weight gain