***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 Adherence to a Mediterranean diet may improve longevity , but relevant data are limited . METHODS We conducted a population -based , prospect i ve investigation involving 22,043 adults in Greece who completed an extensive , vali date d , food-frequency question naire at base line .  Adherence to the traditional Mediterranean diet was assessed by a 10-point Mediterranean-diet scale that incorporated the salient characteristics of this diet ( range of scores , 0 to 9 , with higher scores indicating greater adherence ) . We used proportional-hazards regression to assess the relation between adherence to the Mediterranean diet and total mortality , as well as mortality due to coronary heart disease and mortality due to cancer , with adjustment for age , sex , body-mass index , physical-activity level , and other potential confounders . RESULTS During a median of 44 months of follow-up , there were 275 deaths . A higher degree of adherence to the Mediterranean diet was associated with a reduction in total mortality ( adjusted hazard ratio for death associated with a two-point increment in the Mediterranean-diet score , 0.75 [ 95 percent confidence interval , 0.64 to 0.87 ] ) . An inverse association with greater adherence to this diet was evident for both death due to coronary heart disease ( adjusted hazard ratio , 0.67 [ 95 percent confidence interval , 0.47 to 0.94 ] ) and death due to cancer ( adjusted hazard ratio , 0.76 [ 95 percent confidence interval , 0.59 to 0.98 ] ) . Associations between individual food groups contributing to the Mediterranean-diet score and total mortality were generally not significant . CONCLUSIONS Greater adherence to the traditional Mediterranean diet is associated with a significant reduction in total mortality Weight loss causes  bone mineral loss .  Higher protein diets continue to be criticized for further potential harmful bone effects , including elevated urinary calcium , but may promote bone health if protein sources include dairy . Overweight middle-aged subjects ( n = 130 , 59 males ) were r and omized to a diet providing 1.4 g.kg(-1).d(-1 ) protein and 3 daily servings of dairy ( PRO ) or 0.8 g.kg(-1).d(-1 ) protein and 2 daily servings of dairy ( CARB ) for 4 mo of weight loss plus 8 mo of weight maintenance . Diets prescribed 6276 kJ/d for females and 7113 kJ/d for males . Bone mineral content and density ( BMD ) for whole body ( WB ) , lumbar spine ( LS ) and total hip ( TH ) were measured using dual X-ray absorptiometry , and dietary intake using 3-d weighed food records . Urinary calcium was measured using 24-h collection at 0 and 8 mo for a sub sample ( n = 42 ) . Participants lost body weight ( mean , 95 % CI ) of 8.2 % ( 7.5 - 8.9 % ) at 4 mo , 10.6 % ( 9.5 - 11.8 % ) at 8 mo , and 10.5 % ( 8.9 - 12.0 % ) at 12 mo without differences between groups at any time ( P = 0.64 ) . At 12 mo , PRO BMD was higher by 1.6 % ( 0.3 - 3.0 % ) at WB , 2.1 % ( 0.6 - 3.7 % ) at LS , and 1.4 % ( 0.2 - 2.5 % ) at TH compared with  CARB  .  PRO calcium intake was higher ( PRO : 1140 + /- 58 mg/d , CARB : 766 + /- 46 ; P < 0.01 ) , as was urinary calcium ( PRO : 163 + /- 15 mg/d , CARB : 100 + /- 9.2 ; P < 0.01 ) . A reduced-energy diet supplying 1.4 g.kg(-1).d(-1 ) protein and 3 dairy servings increased urinary calcium excretion but provided improved calcium intake and attenuated bone loss over 4 mo of weight loss and 8 additional mo of weight maintenance BACKGROUND Consuming foods low in energy density ( kcal/g ) decreases energy intake over several days , but the effectiveness of this strategy for weight loss has not been tested . OBJECTIVE The effects on weight loss of 2 strategies for reducing the energy density of the diet were compared over 1 y. DESIGN Obese women ( n = 97 ) were r and omly assigned to groups counseled either to reduce their fat intake ( RF group ) or to reduce their fat intake and increase their intake of water-rich foods , particularly fruit and vegetables ( RF+FV group ) . No goals for energy or fat intake were assigned ; the subjects were instructed to eat ad libitum amounts of food while following the principles of their diet . RESULTS After 1 y , study completers ( n = 71 ) in both groups had significant decreases in body weight ( P < 0.0001 ) . Subjects in the RF+FV group , however , had a significantly different pattern of weight loss ( P = 0.002 ) than did subjects in the RF group . After 1 y , the RF+FV group lost 7.9 + /- 0.9 kg and the RF group lost 6.4 + /- 0.9 kg . Analysis of all r and omly assigned subjects also showed a different pattern of weight loss between groups ( P = 0.021 ) . Diet records indicated that both groups had similar reductions in fat intake . The RF+FV group , however , had a lower dietary energy density than did the RF group ( P = 0.019 ) as the result of consuming a greater weight of food ( P = 0.025 ) , especially fruit and vegetables ( P = 0.037 ) . The RF+FV group also reported less hunger ( P = 0.003 ) . CONCLUSION Reducing dietary energy density , particularly by combining increased fruit and vegetable intakes with decreased fat intake , is an effective strategy for managing body weight while controlling hunger BACKGROUND A vegetarian diet may lead to numerous health benefits , including weight loss . OBJECTIVE We examined the joint effects of personal preference of dietary treatment and a calorie-restricted , low-fat lactoovovegetarian diet ( LOV-D ) compared with a st and ard calorie-restricted , low-fat omnivorous diet ( STD-D ) on changes in weight , total cholesterol , ratio of LDL to HDL cholesterol ( LDL : HDL cholesterol ) , triacylglycerols , insulin resistance , and macronutrient intake during an 18-mo study . DESIGN This was a r and omized clinical trial of 176 overweight and obese adults who were recruited and r and omly assigned first to 1 of 2 preference conditions ( yes or no ) . If assigned to Preference-No , they were r and omly assigned to 1 of the 2 diet conditions ( STD-D or LOV-D ) . If assigned to Preference-Yes , they were assigned to the diet they indicated as preferred at screening . The 12-mo intervention was followed by a 6-mo maintenance phase . RESULTS Participants were mainly women ( 86.9 % ) and white ( 70.5 % ) ; 75 % completed the 18-mo study . A significant interaction between preference and dietary treatment was not observed for any of the outcome variables . However , participants in the Preference-No groups significantly decreased their triacylglycerols ( P = 0.04 ) . The only effect observed for diet was a borderline significant decrease in LDL : HDL cholesterol for the LOV-D group ( P = 0.06 ) . Within the LOV-D groups , those who were 100 % adherent to the LOV-D had significant and marginally significant reductions in monounsaturated fat ( P = 0.02 ) and total fat ( P = 0.05 ) intakes at 18 mo . CONCLUSIONS Our findings suggest that neither prescribing a vegetarian diet nor allowing persons to choose their preferred diet had a significant effect on outcome measures . However , all participants had a significant reduction in total energy and fat intakes and an increase in energy expenditure , which was reflected in reduced body weight . This clinical trial was registered at www . clinical trials.gov as NCT00330629 BACKGROUND Despite interest in the glycemic index diets as an approach to weight control , few long-term evaluations are available . OBJECTIVE The objective was to investigate the long-term effect of a low-glycemic-index ( LGI ) diet compared with that of a high-glycemic-index ( HGI ) diet ; all other dietary components were equal . DESIGN After a 6-wk run-in , we r and omly assigned 203 healthy women [ body mass index ( in kg/m2 ) : 23 - 30 ] aged 25 - 45 y to an LGI or an HGI diet with a small energy restriction . The primary outcome measure was weight change at 18 mo . Secondary outcomes included hunger and fasting insulin and lipids . RESULTS Despite requiring a run-in and the use of multiple incentives , only 60 % of the subjects completed the study . The difference in glycemic index between the diets was approximately 35 - 40 units ( 40 compared with 79 ) during all 18 mo of follow-up , and the carbohydrate intake from energy remained at approximately 60 % in both groups . The LGI group had a slightly greater weight loss in the first 2 mo of follow-up ( -0.72 compared with -0.31 kg ) , but after 12 mo of follow-up both groups began to regain weight . After 18 mo , the weight change was not significantly different ( P = 0.93 ) between groups ( LGI : -0.41 kg ; HGI : -0.26 kg ) . A greater reduction was observed in the LGI diet group for triacylglycerol ( difference = -16.4 mg/dL ; P = 0.11 ) and VLDL cholesterol ( difference = -3.7 mg/dL ; P = 0.03 ) . CONCLUSIONS Long-term weight changes were not significantly different between the HGI and LGI diet groups ; therefore , this study does not support a benefit of an LGI diet for weight control . Favorable changes in lipids confirmed previous results CONTEXT The results of clinical trials involving diet in the treatment of obesity have been inconsistent , possibly due to inherent physiological differences among study participants . OBJECTIVE To determine whether insulin secretion affects weight loss with 2 popular diets . DESIGN , SETTING , AND PARTICIPANTS R and omized trial of obese young adults ( aged 18 - 35 years ; n = 73 ) conducted from September 2004 to December 2006 in Boston , Mass , and consisting of a 6-month intensive intervention period and a 12-month follow-up period . Serum insulin concentration at 30 minutes after a 75-g dose of oral glucose was determined at baseline as a measure of insulin secretion . Outcomes were assessed at 6 , 12 , and 18 months . Missing data were imputed conservatively . INTERVENTIONS A low-glycemic load ( 40 % carbohydrate and 35 % fat ) vs low-fat ( 55 % carbohydrate and 20 % fat ) diet . MAIN OUTCOME MEASURES Body weight , body fat percentage determined by dual-energy x-ray absorptiometry , and cardiovascular disease risk factors . RESULTS Change in body weight and body fat percentage did not differ between the diet groups overall . However , insulin concentration at 30 minutes after a dose of oral glucose was an effect modifier ( group x time x insulin concentration at 30 minutes : P = .02 for body weight and P = .01 for body fat percentage ) . For those with insulin concentration at 30 minutes above the median ( 57.5 microIU/mL ; n = 28 ) , the low-glycemic load diet produced a greater decrease in weight ( -5.8 vs -1.2 kg ; P = .004 ) and body fat percentage ( -2.6 % vs -0.9 % ; P = .03 ) than the low-fat diet at 18 months . There were no significant differences in these end points between diet groups for those with insulin concentration at 30 minutes below the median level ( n = 28 ) . Insulin concentration at 30 minutes after a dose of oral glucose was not a significant effect modifier for cardiovascular disease risk factors . In the full cohort , plasma high-density lipoprotein cholesterol and triglyceride concentrations improved more on the low-glycemic load diet , whereas low-density lipoprotein cholesterol concentration improved more on the low-fat diet . CONCLUSIONS Variability in dietary weight loss trials may be partially attributable to differences in hormonal response . Reducing glycemic load may be especially important to achieve weight loss among individuals with high insulin secretion . Regardless of insulin secretion , a low-glycemic load diet has beneficial effects on high-density lipoprotein cholesterol and triglyceride concentrations but not on low-density lipoprotein cholesterol concentration . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00130299 OBJECTIVE Studies suggest that high-dairy and high-fiber/low-glycemic index diets may facilitate weight loss , but data are conflicting . The effects on weight loss and body fat of a 
    Output:
    
In conclusion , most diets where the weight loss was > 5 % of initial weight were energy restricted .
Furthermore , following low carbohydrate or Mediterranean diets can be an alternative to isolated energy restriction , but these data are yet to be confirmed