***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: The effects of meal size and frequency on thermic effect of food ( TEF ) were examined in seven healthy normal-weight young women . Each volunteer consumed in r and om order one of two identical meals [ 3138 kJ ( 750 kcal ) , 54.5 % carbohydrate , 14.0 % protein , 31.5 % fat ] . One meal was taken over 10 min [ large meal ( LM ) ] whereas the other was taken in six equal portions of 523 kJ ( 125 kcal ) at 30-min intervals over a 3-h period [ small meals ( SM ) ] . Metabolic rate was measured for 1 h before and every 30 min after the meal started for 5 h. When expressed as either kJ/min ( kcal/min ) or kJ/5h ( kcal/5h ) , TEF was significantly higher in the LM day than in the SM day ( P less than 0.05 ) . We conclude that the temporal pattern in which a mixed caloric load is eaten affects the thermogenic response and may be an important determinant of energy balance after a meal Fifty-two moderately obese adult women were stratified according to their baseline breakfast-eating habits and r and omly assigned a weight-loss program . The no-breakfast group ate two meals per day and the breakfast group ate three meals per day . The energy content of the two weight-loss programs was identical . After the 12-wk treatment , baseline breakfast eaters lost 8.9 kg in the no-breakfast treatment and 6.2 kg in the breakfast treatment . Baseline breakfast skippers lost 7.7 kg in the breakfast treatment and 6.0 kg in the no-breakfast treatment . This treatment-by-strata-by-time interaction effect ( P less than 0.06 ) suggests that those who had to make the most substantial changes in eating habits to comply with the program achieved better results . Analyses of behavioral data suggested that eating breakfast helped reduce dietary fat and minimize impulsive snacking and therefore may be an important part of a weight-reduction program BACKGROUND Different dietary fats are metabolized differently in humans and may influence energy expenditure , substrate oxidation , appetite regulation , and body weight regulation . OBJECTIVE We examined the short-term effects of 4 triacylglycerols ( test fats ) on subjective appetite , ad libitum energy intake , meal-induced thermogenesis , and postpr and ial substrate oxidation . DESIGN Eleven healthy , normal-weight men ( mean age : 25.1 + /- 0.5 y ) consumed 4 different test fats [ conventional fat ( rapeseed oil ) and 3 modified fats ( lipase-structured fat , chemically structured fat , and physically mixed fat ) ] in a r and omized , double-blind , crossover design . RESULTS No significant differences in appetite sensations or ad libitum energy intakes were observed between the 4 test fats . Overall , the 4 fats exerted different effects on energy expenditure ( meal effect : P < 0.01 ) and substrate oxidation ( interaction between meal and time : P < 0.05 ) . In post hoc tests , the 3 modified fats result ed in significantly higher postpr and ial energy expenditure and fat oxidation than did the conventional fat ( P < 0.008 , Bonferroni adjusted ) ; no significant differences were observed between the 3 modified fats . CONCLUSIONS Structured fats do not change short-term postpr and ial appetite sensations or ad libitum energy intakes but do result in higher postpr and ial energy expenditure and fat oxidation than do conventional fats and hence promote negative energy and fat balance . In humans , a physically mixed fat ( trioctanoate + rapeseed oil ) is metabolized as quickly as are structured fats . The position of medium-chain fatty acids on the glycerol backbone of triacylglycerols does not seem to affect energy expenditure or appetite Background : Popular beliefs that breakfast is the most important meal of the day are grounded in cross-sectional observations that link breakfast to health , the causal nature of which remains to be explored under real-life conditions . Objective : The aim was to conduct a r and omized controlled trial examining causal links between breakfast habits and all components of energy balance in free-living humans . Design : The Bath Breakfast Project is a r and omized controlled trial with repeated- measures at baseline and follow-up in a cohort in southwest Engl and aged 21–60 y with dual-energy X-ray absorptiometry – derived fat mass indexes ≤11 kg/m2 in women ( n = 21 ) and ≤7.5 kg/m2 in men ( n = 12 ) . Components of energy balance ( resting metabolic rate , physical activity thermogenesis , energy intake ) and 24-h glycemic responses were measured under free-living conditions with r and om allocation to daily breakfast ( ≥700 kcal before 1100 ) or extended fasting ( 0 kcal until 1200 ) for 6 wk , with baseline and follow-up measures of health markers ( eg , hematology/biopsies ) . Results : Contrary to popular belief , there was no metabolic adaptation to breakfast ( eg , resting metabolic rate stable within 11 kcal/d ) , with limited subsequent suppression of appetite ( energy intake remained 539 kcal/d greater than after fasting ; 95 % CI : 157 , 920 kcal/d ) . Rather , physical activity thermogenesis was markedly higher with breakfast than with fasting ( 442 kcal/d ; 95 % CI : 34 , 851 kcal/d ) . Body mass and adiposity did not differ between treatments at baseline or follow-up and neither did adipose tissue glucose uptake or systemic indexes of cardiovascular health . Continuously measured glycemia was more variable during the afternoon and evening with fasting than with breakfast by the final week of the intervention ( CV : 3.9 % ; 95 % CI : 0.1 % , 7.8 % ) . Conclusions : Daily breakfast is causally linked to higher physical activity thermogenesis in lean adults , with greater overall dietary energy intake but no change in resting metabolism . Cardiovascular health indexes were unaffected by either of the treatments , but breakfast maintained more stable afternoon and evening glycemia than did fasting . This trial was registered at www.is rct n.org as IS RCT N31521726 OBJECTIVE : To study the effect of diet composition on diet-induced thermogenesis ( DIT ) over 24 h in a respiration chamber . SUBJECTS : Eight healthy female volunteers ( age 27±3 y ; body mass index , BMI 23±3 kg/m2).DIETS  : A high protein and carbohydrate ( HP/C ) ( 60:10:30 ; percentage energy (E%)carbohydrate , fat and protein , respectively ) and high fat ( HF ) ( 30:60:10 respectively ) diet , both isoenergetic , isovolumetric , composed of normal food items and matched for organoleptic properties ( taste , smell , appearance ) . DESIGN : Subjects spent two 36 h periods each in a respiration chamber consuming both test diets in r and om order . Components of 24 h energy expenditure ( 24 h EE ) : sleeping metabolic rate , DIT and activity induced energy expenditure were measured . RESULTS : DIT was higher in all subjects while on the HP/C diet ( 1295 kJ/d vs 931 kJ/d ; 14.6 % vs 10.5 % of energy intake ; P<0.02 ) . There was no significant difference in other components or total 24 h EE , although there was a trend towards higher EE on the HP/C diet . CONCLUSION : A high protein and carbohydrate diet induces a greater thermic response in healthy individuals when compared to a high fat diet BACKGROUND & AIMS To compare the acute effects of three fatty meals with different fat quality on postpr and ial thermogenesis , substrate oxidation and satiety . METHODS Twenty-nine healthy men aged between 18 and 30 years participated in a r and omised crossover trial comparing the thermogenic effects of three isocaloric meals : high in polyunsaturated fatty acids from walnuts , high in monounsaturated fatty acids from olive oil , and high in saturated fatty acids from fat-rich dairy products . Indirect calorimetry was used to determine resting metabolic rate , respiratory quotient , 5-h postpr and ial energy expenditure and substrate oxidation . Satiety was estimated by using visual analogue scales and measuring caloric intake in a subsequent ad libitum meal . RESULTS Five-h postpr and ial thermogenesis was higher by 28 % after the high-polyunsaturated meal ( p=0.039 ) and by 23 % higher after the high-monounsaturated meal ( p=0.035 ) compared with the high-saturated meal . Fat oxidation rates increased nonsignificantly after the two meals rich in unsaturated fatty acids and decreased nonsignificantly after the high-saturated fatty acid meal . Postpr and ial respiratory quotient , protein and carbohydrate oxidation , and satiety measures were similar among meals . CONCLUSIONS Fat quality determined the thermogenic response to a fatty meal but had no clear effects on substrate oxidation or satiety We investigated the effects of food palatability on the thermic effect of feeding ( TEF ) , substrate oxidation and circulating glucose and insulin .  Healthy young men ( 23.4+/-1.0 , SD , years , n=10 ) and older men ( 69.4+/-1.3 , years , n=9 ) were resident in a metabolic unit for two 2-day study periods . On the second day of each period , they consumed in r and om order either a palatable test meal containing 2.93 MJ or a nonpalatable control meal containing the same foods in identical amounts but blended and freeze-dried into biscuit form . TEF and respiratory quotient ( RQ ) were measured over 6 h and blood sample s were taken for measurement of glucose and insulin . Age group had no effect on TEF , RQ or circulating glucose other than to delay the time of peak TEF ( P<0.002 for both meals ) . There was no significant effect of meal type on TEF , but RQ and circulating glucose were higher following consumption of the palatable meal ( P<0.001 for both parameters ) . These results suggest that over 6 h postpr and ial , consumption of palatable foods does not increase TEF , but is instead associated with increased glycemic response and increased carbohydrate oxidation . These changes , combined with previous work on the glycemic index , predict an accelerated return of hunger and increased energy intake at subsequent meals following consumption of palatable vs. control foods . Further studies are needed to examine the possible mechanism for this previously suggested " second meal " effect of diet palatability on energy intake OBJECTIVE To determine whether medium-chain triglycerides , in low-to-moderate amounts consumed with meals ( at breakfast , lunch and dinner ) , can increase daily energy expenditure ( EE ) and 24-h urinary excretion of catecholamines in  humans  . DESIGN Dose-response study conducted under double-blind r and omised design . SETTING Respiratory chamber at the Faculty of Medicine , University of Geneva . SUBJECTS Eight healthy young men were recruited from the student population by advertisement in our Faculty . METHODS 24-h EE and urinary catecholamines were measured in each subject during stay in a respiratory chamber on four separate occasions . These were r and omised between four different combinations of medium-chain triglycerides ( MCT ) and long-chain triglycerides ( LCT ) , a total 30g/day , which was consumed with their habitual diet in three equal parts ( 10 g each ) at breakfast , lunch , and dinner in the following ratio of MCT : LCT ( g/g ) 0:30 , 5:25 , 15:15 and 30:0 . RESULTS 24-h EE increased significantly with increasing MCT : LCT ratio ( ANOVA , P < 0.001 ) , with the diet providing a total of 15 - 30 g MCT per day stimulating 24-h EE by 5 % : this corresponds to a mean absolute increase in daily EE of approximately 500kJ , with individual values varying between 268 kJ and 756 kJ. No significant differences were observed in respiratory quotient nor in urinary nitrogen losses across diets , but 24-h urinary noradrenaline was significantly increased ( ANOVA , P < 0.025 ) , whereas adrenaline and dopamine were unaltered . CONCLUSIONS This study suggests that relatively low-to-moderate intake of MCT ( 15 - 30 g per day ) as part of habitual diet may play a role in the control of human body composition by enhancing daily EE , and that this effect is mediated at least in part through activation of the sympathetic nervous system Objective : To compare postpr and ial whole-body fat oxidation rates in humans , following  high-fat ( 43 % of total energy ) mixed breakfast meals , of fixed energy and macronutrient composition , rich in either monounsaturated fat ( MUFA ) from extra virgin olive oil or saturated fat ( SFA ) from cream . Design : Paired comparison of resting metabolic rate ( RMR ) , thermic effect of a meal and substrate oxidation rates following consumption of isocaloric breakfast meals , 
    Output:
    
Meals with a high protein or carbohydrate content had a higher DIT than high fat , although this effect was not always significant .
Unclear or inconsistent findings were found by comparing the consumption of meals quickly or slowly , and palatability was not significantly associated with DIT .
These findings indicate that the magnitude of the increase in DIT is influenced by the energy intake , macronutrient composition , and eating pattern of the meal