***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 Increases in both the portion size and energy density of food have both been shown to increase energy intake , but the combined effects of such increases have not been investigated . OBJECTIVE The objective was to determine the combined effects of energy density and portion size on energy  intake in women . DESIGN This study used a within-subjects design . Once a week for 6 wk , 39 women were served breakfast , lunch , and dinner ad libitum . The main entrée at lunch was formulated in 2 versions that varied in energy density ( 5.23 or 7.32 kJ/g ) , each of which was served in 3 different portion sizes ( 500 , 700 , or 900 g ) . The 2 versions were matched for macronutrient composition and palatability . Breakfast and dinner were st and ard meals . RESULTS Increases in portion size and energy density led to independent and additive increases in energy intake ( P < 0.0001 ) . Subjects consumed 56 % more energy ( 925 kJ ) when served the largest portion of the higher energy-dense entrée than when served the smallest portion of the lower energy-dense entrée . Subjects did not compensate for the additional intake by eating less at the subsequent meal . Despite substantial differences in energy intake , no systematic differences in ratings of hunger and fullness across conditions were observed . CONCLUSIONS The energy density and the portion size of a food act independently to affect energy intake . The findings indicate that large portions of foods with a high energy density may facilitate the overconsumption of energy BACKGROUND An impaired ability to compensate for calories and increased eating in the absence of hunger ( EAH ) has been associated with increased energy intake and weight gain in unrelated children . OBJECTIVE The aims of this study were to compare caloric compensation [ the percentage compensation index ( % COMPX ) ] and EAH in weight-discordant siblings aged 5 - 12 y. DESIGN In a crossover , behavioral genetics design , 47 same-sex sibling pairs ( 53 % female , 55 % full siblings ) were served dinner once a week for 3 wk . Across conditions , siblings were served the same dinner , but 25 min before dinner , they either consumed in full or did not consume 1 of 2 preloads that varied in energy density ( ED ; 0.57 or 0.97 kcal/g ) . On the day when no preload was consumed , EAH was assessed after dinner and defined as the number of calories consumed from snacks . RESULTS Overweight/obese siblings undercompensated [ % COMPX : -48.8 ± 56.3 ( mean ± SEM ) ] and therefore overate after the high-ED preload , whereas normal-weight siblings showed accurate compensation ( % COMPX : 101.3 ± 51.9 ; P = 0.03 ) . Furthermore , overweight/obese siblings consumed 34 % more calories ( 93 kcal ) in the absence of hunger than did normal-weight siblings ( P = 0.01 ) . Within-pair resemblances for % COMPX and EAH were stronger for full siblings ( P < 0.049 ) than for half siblings ( P > 0.23 ) . CONCLUSIONS An impaired ability to regulate short-term energy intake , which includes incomplete adjustment for calorie differences in a preload and eating when satiated , may represent a behavioral phenotype for obesity in children . Future studies should test whether teaching children to focus on internal satiety cues may prevent at-risk children from overeating Background The purpose of this study was to determine whether a high-protein afternoon yogurt snack  improves appetite control , satiety , and reduces subsequent food intake compared to other commonly-consumed , energy dense , high-fat snacks . Findings Twenty , healthy women ( age : 27 ± 2 y ; BMI : 23.4 ± 0.7 kg/m2 ) completed the r and omized crossover design study which included 3 , 8-h testing days comparing the following 160 kcal afternoon snacks : high-protein yogurt ( 14 g protein/25 g CHO/0 g fat ) ; high-fat crackers ( 0 g protein/19 g CHO/9 g fat ) ; and high-fat chocolate ( 2 g protein/19 g CHO/9 g fat ) . Participants were acclimated to each snack for 3 consecutive days . On day 4 , the participants consumed a st and ardized breakfast and lunch ; the respective snack was consumed 3-h post-lunch . Perceived hunger and fullness were assessed throughout the afternoon until dinner was voluntarily requested . An ad libitum dinner was then provided . The consumption of the yogurt snack led to greater reductions in afternoon hunger vs. chocolate ( p < 0.01 ) . No differences in afternoon fullness were detected . The yogurt snack also delayed eating initiation by approximately 30 min compared to the chocolate snack ( p < 0.01 ) and approximately 20 min vs. crackers ( p = 0.07 ) . The yogurt snack led to approximately 100 fewer kcals consumed at dinner vs. the crackers ( p = 0.08 ) and chocolate ( p < 0.05 ) . No other differences were detected . Conclusion These data suggest that , when compared to high-fat snacks , eating less energy dense , high-protein snacks like yogurt  improves appetite control , satiety , and reduces subsequent food intake in healthy women This study tested the hypothesis that the amount ( weight or volume ) of food consumed affects the satiating potency of a food , independent of its energy content . Normal-weight young men ( n = 20 ) were tested in a within-subjects design . Subjects were served a milk-based drink or no drink ( control ) , followed 30 min later by a self-selected lunch and > 4 h later by a self-selected dinner . Milk drinks were equal in energy content ( 2088 kJ , or 499 kcal ) and had similar proportions of fat ( 30.3 % ) , carbohydrate ( 54.7 % ) , and protein ( 15 % ) across three volumes : 300 , 450 , and 600 mL. Ratings of palatability , sensory properties , and energy content of the drinks and of hunger completed before consumption of the preloads were not significantly different among conditions . The results showed that preload volume affected energy intake at lunch ( P < or = 0.009 ) such that energy intake was less after the 600-mL preload than after the 300-mL preload . This effect was still present when energy intake at dinner was included ( P < or = 0.022 ) . At lunch , including energy from the preload , subjects overate relative to the control condition ( 4323 + /- 322 kJ ) after the 300- ( 5263 + /- 321 kJ ) and 450-mL ( 5011 + /- 300 kJ ) preloads but not after the 600-mL ( 4703 + /- 353 kJ ) preload . Thus , the best adjustment for the energy in the preloads was with the largest , least energy-dense drink . Consistent with the effects on intake , the volume of the drinks affected ratings of hunger and fullness . These results indicate that the volume consumed is an important determinant of satiety after milk drinks under these conditions BACKGROUND The results of previous studies indicated that energy density , independent of fat content , influences energy intake . In most studies , however , both fat content and energy density were lower than in typical American diets . OBJECTIVE We examined the influence of energy density on intake when fat content was above , below , or similar to the amount of fat typically consumed and when energy density was closer to that of American diets . DESIGN Lean ( n = 19 ) and obese ( n = 17 ) women consumed all meals daily in our laboratory during 6 experimental sessions . The main entrées , consumed ad libitum , were formulated to vary in fat content ( 25 % , 35 % , and 45 % of energy ) and energy density ( 5.23 kJ/g , or low energy density , and 7.32 kJ/g , or high energy density ) but to have similar palatability . RESULTS Energy density influenced energy intake across all fat contents in both lean and obese women ( P < 0.0001 ) . Women consumed less energy in the low ( 7531 kJ ) than in the high ( 9414 kJ ) energy density condition . Despite this 20 % lower energy intake , there were only small differences in hunger ( 7 % ) and fullness ( 5 % ) . Women consumed a similar volume , but not weight , of food daily across conditions . Differences in intake by weight , but not volume , occurred because for some versions of manipulated foods , weight and volume were not directly proportional . CONCLUSIONS Energy density affected energy intake across different fat contents and at levels of energy density comparable with those in typical diets . Furthermore , our findings suggest that cues related to the amount of food consumed have a greater influence on short-term intake than does the amount of energy consumed BACKGROUND Studies have shown that energy intake increases when both the fat content and energy density of the entire diet increases . When the fat content and energy density vary independently of one another , however , energy density , but not fat content , influences intake . OBJECTIVE The present study examined whether energy intake in lean and obese women is affected when either the energy density or the fat content of a portion of the diet is manipulated and palatability is held constant . DESIGN In a within-subjects design , 17 lean and 17 obese women consumed meals in the laboratory for four , 4-d test periods . In 3 of these test periods the energy density ( 4.4 and 6.7 kJ/g ) or the fat content ( 16 % and 36 % of energy ) of compulsory entrees representing 50 % of each subject 's usual energy intake was manipulated . Additional self-selected foods were consumed ad libitum at meals and as snacks . RESULTS There were no systematic differences in palatability of the manipulated foods across conditions . Obese and lean participants responded similarly to the dietary manipulations . Intake of self-selected foods at meals was reduced significantly by 16 % for both lean and obese subjects in the low- compared with the high-energy-density condition . The fat content of the compulsory foods had no significant effect on energy intake . Ratings of hunger did not differ between diets . CONCLUSION These results indicate that when a portion of the diet was manipulated , the energy density , but not the fat content , of the foods affected total energy intake at meals in both lean and obese women BACKGROUND Little is known about the long-term effects of dietary energy density ( ED ) on weight gain . OBJECTIVE The objective was to assess the long-term relation between changes in dietary ED and age-related weight gain . DESIGN We conducted a prospect i ve study of 50 026 women ( x + /- SD age : 36.5 + /- 4.6 y ) in the Nurses ' Health Study II followed from 1991 to 1999 .  Dietary ED and body weight were ascertained in 1991 , 1995 , and 1999 .  Total dietary ED  was calculated by dividing each subject 's daily energy intake ( kcal ) by the reported weight ( g ) of all foods consumed . RESULTS Dietary ED was positively correlated with saturated fat ( r = 0.16 ) , trans fat ( r = 0.15 ) , and the glycemic index ( r = 0.16 ) , but was inversely correlated with vegetable protein ( r = -0.30 ) , vegetables ( r = -0.27 ) , and fruit ( r = -0.17 ) . ED was not significantly correlated with total fat intake as a percentage of energy ( r = 0.08 ) . Women who increased their dietary ED during follow-up the most ( 5th quintile ) had a significantly greater multivariate-adjusted weight gain than did those who decreased their dietary ED ( 1st quintile ) ( 8-y time period : 6.42 kg compared with 4.57 kg ; P for trend < 0.001 ) . However , the amount of weight change over time varied considerably according to the ED values of individual foods and beverages . CONCLUSION A high dietary ED reflects a dietary pattern higher in saturated and trans fats and refined carbohydrates . Increases in dietary ED were associated with greater weight gain  among middle-aged women during 8 y of follow-up . However , public health recommendations can not be made simply on the basis of ED values of individual foods and beverages Although several studies have assessed the influence of the glycemic index on body weight and blood pressure among adults , limited evidence exists for the pediatric age population . In the current study , we compared the effects of low glycemic index ( LGI ) diet to the healthy nutritional recommendation (HNR)-based diet on obesity and blood pressure among adolescent girls in pubertal ages . This 10-week parallel r and omized clinical trial comprised of 50 overweight or obese and sexually mature girls less than 18 years of age years , who were r and omly assigned  to LGI or HNR-based diet . Macronutrient distribution was equivalently prescribed in both groups . Blood pressure , weight and waist circumference were measured at baseline and after intervention . Of the 50 participants , 41 subjects ( include 82 % ) completed the study . The GI of the diet in the LGI group was 42.67 ± 0.067 . A within-group analysis illustrated that in comparison to the baseline values , the body weight and body mass index ( not waist circumference and blood pressure ) decreased significantly after the intervention in both groups ( P = 
    Output:
    
In summary , the current analysis revealed that we can restrict the energy intake by consuming an LED preload .
Moreover , consuming an LED preload could favorably affect preload+meal energy intake