***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 Minnesota Coronary Survey was a 4.5-year , open enrollment , single end-time , double-blind , r and omized clinical trial that was conducted In six Minnesota state mental hospitals and one nursing home . It Involved 4393 Institutionalized men and 4664 Institutionalized women . The trial compared the effects of a 39 % fat control diet ( 18 % saturated fat , 5 % polyunsaturated fat , 16 % monounsaturated fat , 446 mg dietary cholesterol per day ) with a 38 % fat treatment diet ( 9 % saturated fat , 15 % polyunsaturated fat , 14 % monounsaturated fat , 166 mg dietary cholesterol per day ) on serum cholesterol levels and the Incidence of myocardlal Infa rct ions , sudden deaths , and all-cause mortality . The mean duration of time on the diets was 384 days , with 1568 subjects consuming the diet for over 2 years . The mean serum cholesterol level In the pre-admission period was 207 mg/dl , falling to 175 mg/dl in the treatment group and 203 mg/dl In the control group . For the entire study population , no differences between the treatment and control groups were observed for cardiovascular events , cardiovascular deaths , or total mortality . A favorable trend for all these end-points occurred In some younger age groups CONTEXT Obesity in the United States has increased dramatically during the past several decades . There is debate about optimum calorie balance for prevention of weight gain , and proponents of some low-carbohydrate diet regimens have suggested that the increasing obesity may be attributed , in part , to low-fat , high-carbohydrate diets . OBJECTIVES To report data on body weight in a long-term , low-fat diet trial for which the primary end points were breast and colorectal cancer and to examine the relationships between weight changes and changes in dietary components . DESIGN , SETTING , AND PARTICIPANTS R and omized intervention trial of 48,835 postmenopausal women in the United States who were of diverse background s and ethnicities and participated in the Women 's Health Initiative Dietary Modification Trial ; 40 % ( 19,541 ) were r and omized to the intervention and 60 % ( 29,294 ) to a control group . Study enrollment was between 1993 and 1998 , and this analysis includes a mean follow-up of 7.5 years ( through August 31 , 2004 ) . INTERVENTIONS The intervention included group and individual sessions to promote a decrease in fat intake and increases in vegetable , fruit , and grain consumption and did not include weight loss or caloric restriction goals . The control group received diet-related education material s. MAIN OUTCOME MEASURE Change in body weight from baseline to follow-up . RESULTS Women in the intervention group lost weight in the first year ( mean of 2.2 kg , P<.001 ) and maintained lower weight than control women during an average 7.5 years of follow-up ( difference , 1.9 kg , P<.001 at 1 year and 0.4 kg , P = .01 at 7.5 years ) . No tendency toward weight gain was observed in intervention group women overall or when stratified by age , ethnicity , or body mass index . Weight loss was greatest among women in either group who decreased their percentage of energy from fat . A similar but lesser trend was observed with increases in vegetable and fruit servings , and a nonsignificant trend toward weight loss occurred with increasing intake of fiber . CONCLUSION A low-fat eating pattern does not result in weight gain  in postmenopausal women . Clinical Trial Registration Clinical Trials.gov , NCT00000611 BACKGROUND Dietary factors and very-long-chain n-3 polyunsaturated fatty acids ( n-3 PUFAs ) may influence the atherothrombotic process . Elevated concentrations of circulating cell adhesion molecules , thrombomodulin ( TM ) , von Willebr and factor ( vWF ) , and tissue-type plasminogen activator antigen ( tPAag ) are related to atherothrombotic cardiovascular disease . OBJECTIVE The r and omized Diet and Omega-3 Intervention Trial ( DOIT ) targeted a comparison of the effect of 3-y dietary counseling , n-3 PUFA supplementation ( 2.4 g/d ) , or both on circulating markers of endothelial activation . DESIGN The study included 563 elderly men with long-st and ing hyperlipidemia . The men were r and omly assigned by factorial design into 4 groups : control ( no dietary counseling and placebo capsules ) , dietary counseling ( and placebo capsules ) , n-3 PUFA supplementation ( no dietary counseling ) , and dietary counseling and n-3 PUFA supplementation . RESULTS Serum concentrations of fatty acids reflected good compliance . Dietary counseling was followed by significantly reduced concentrations of soluble intercellular adhesion molecule 1 ( sICAM-1 ; P < 0.001 ) , sTM ( P = 0.004 ) , and tPAag ( P < 0.001 ) than in subjects without dietary counseling . After n-3 PUFA supplementation , significantly reduced concentrations of sICAM-1 ( P < 0.001 ) and sTM ( P = 0.006 ) were observed when compared with subjects receiving placebo capsules . An increase in tPAag was not significantly different from that observed in subjects receiving placebo capsules . For sICAM-1 , a significant effect was observed for both interventions combined . CONCLUSIONS Each intervention ( dietary counseling or n-3 PUFA supplements ) reduced sTM and sICAM-1 concentrations , indicating decreased endothelial activation . The tPAag increase in the groups not receiving dietary counseling ( pooled ) , which indicates progression of atherosclerosis , was significantly counteracted by dietary counseling Effects of specific dietary alterations in patients with radiolucent gallstones treated with ursodeoxycholic acid ( UDCA , 750 mg at bedtime ) were investigated . Patients were allocated r and omly to one of four diets : st and ard ( 500 mg cholesterol/day ) , low-cholesterol ( 250 mg/day ) , added-bran ( 30 g/day ) , or substituted medium-chain triglycerides ( MCT ) oil ( 20 % of fat ) . Dietary intake and good compliance were verified by computerized analysis of dietary diaries . Bile-acid kinetics ( 26 patients ) or secretion of biliary lipids ( 23 other patients ) were determined at enrollment and at 6 and 9 mo , respectively , during treatment . Although MCT further decreased the UDCA-induced decrease in the synthesis of chenodeoxycholic acid , it did not lessen desaturation of bile . Otherwise , compared to the st and ard diet , no experimental diet significantly altered the UDCA-induced increase of the pools of total bile acids and UDCA or the UDCA-induced decrease in synthesis of bile acids and in biliary secretion or saturation of cholesterol . If these dietary manipulations facilitate dissolution of gallstones by UDCA , they do so by other mechanisms BACKGROUND The optimal dietary content and type of fat and carbohydrate for weight management has been debated for decades . OBJECTIVE The objective was to compare the effects of 3 ad libitum diets on the maintenance of an initial weight loss of > or=8 % and risk factors for CVD and diabetes during a 6-mo controlled dietary intervention . DESIGN Nondiabetic overweight or obese [ mean + /- SD body mass index ( in kg/m(2 ) ) : 31.5 + /- 2.6 ] men ( n = 55 ) and women ( n = 76 ) aged 28.2 + /- 4.8 y were r and omly assigned to a diet providing a moderate amount of fat ( 35 - 45 % of energy ) and > 20 % of fat as monounsaturated fatty acids ( MUFA diet ; n = 54 ) , to a low-fat ( 20 - 30 % of energy ) diet ( LF diet ; n = 51 ) , or to a control diet ( 35 % of energy as fat ; n = 26 ) . Protein constituted 10 - 20 % of energy in all 3 diets . All foods were provided free of charge from a purpose -built supermarket . RESULTS More subjects dropped out of the MUFA ( 28 % ) group than out of the LF group ( 16 % ) and control group ( 8 % ) ( MUFA compared with control : P < 0.05 ) . All groups regained weight ( MUFA : 2.5 + /- 0.7 kg ; LF : 2.2 + /- 0.7 kg ; and control : 3.8 + /- 0.8 kg ; NS ) . Body fat regain was lower in the LF ( 0.6 + /- 0.6 % ) and MUFA ( 1.6 + /- 0.6 % ) groups than in the control group ( 2.6 + /- 0.5 % ) ( P < 0.05 ) . In the MUFA group , fasting insulin decreased by 2.6 + /- 3.5 pmol/L , the homeostasis model assessment of insulin resistance by 0.17 + /- 0.13 , and the ratio of LDL to HDL by 0.33 + /- 0.13 ; in the LF group , these variables increased by 4.3 + /- 3.0 pmol/L ( P < 0.08 ) and 0.17 + /- 0.10 ( P < 0.05 ) and decreased by 0.02 + /- 0.09 ( P = 0.005 ) , respectively ; and in the control group , increased by 14.0 + /- 4.3 pmol/L ( P < 0.001 ) , 0.57 + /- 0.17 ( P < 0.001 ) , and 0.05 + /- 0.14 ( P = 0.036 ) , respectively . Dietary adherence was high on the basis of fatty acid changes in adipose tissue . CONCLUSIONS Diet composition had no major effect on preventing weight regain . However , both the LF and MUFA diets produced less body fat regain than did the control diet , and the dropout rate was lowest in the LF diet group , whereas fasting insulin decreased and the homeostasis model assessment of insulin resistance and ratio of LDL to HDL improved with the MUFA diet . This trial was registered at clinical trials.gov as NCT00274729 BACKGROUND Dietary fat has been implicated as a risk factor for cardiovascular disease and obesity . OBJECTIVE We evaluated the effect on body weight , body fat , lipids , glucose , and insulin of replacing dietary fat with olestra in moderately obese men . DESIGN Forty-five healthy overweight men were r and omly assigned to 1 of 3 diets : control diet ( 33 % fat ) , fat-reduced diet ( 25 % fat ) , or fat-substituted diet ( one-third of dietary fat replaced by olestra to achieve a diet containing 25 % metabolizable fat ) . Body fat was measured by dual-energy X-ray absorptiometry and visceral and subcutaneous abdominal fat by computed tomography . RESULTS Thirty-six men completed the 9-mo study . Body weight and body fat in the fat-substituted group declined by a mean ( + /- SEM ) of 6.27 + /- 1.66 and 5.85 + /- 1.34 kg , respectively , over 9 mo compared with 3.8 + /- 1.34 and 3.45 + /- 1.0 kg in the control group and 1.79 + /- 0.81 and 1.68 + /- 0.75 kg in the fat-reduced diet group . At 9 mo , the mean difference in body fat between the fat-reduced and fat-substituted groups was -4.19 + /- 1.19 kg ( 95 % CI : -6.57 , -1.81 ) , that between the control and fat-substituted groups was -2.55 + /- 1.21 kg ( -0.13 , -4.97 ) , and that between the control and fat-reduced groups was 1.63 + /- 1.18 kg ( 3.96 , -0.70 ) . The men eating the fat-reduced diet asked for almost no extra foods , in contrast with the significantly higher requests ( P < 0.05 ) from both of the other 2 groups . CONCLUSION Replacement of dietary fat with olestra reduces body weight and total body fat when compared with a 25%-fat diet or a control diet containing 33 % fat This r and omised controlled trial examined anthropometric changes and cardiovascular benefits of six months of weight management in 110 free living women , aged 18–68 y and BMI 25–50 kg/m2 , who received 1200 kcal/d diet treatments of either high ( 58 % energy , n=57 ) or low ( 35 % energy , n=53 ) carbohydrate ( CHO ) content .  Body weight , plasma total 
    Output:
    
Lower weight gain in the low fat arm compared with the control arm was consistent across trials , but the size of the effect varied .
Metaregression suggested that greater reduction in total fat intake and lower baseline fat intake were associated with greater relative weight loss , explaining most of the heterogeneity .
The significant effect of a low fat diet on weight was not lost in sensitivity analyses ( including removing trials that expended greater time and attention on low fat groups ) .
GRADE assessment suggested high quality evidence for the relation between total fat intake and body weight in adults .
There is high quality , consistent evidence that reduction of total fat intake has been achieved in large numbers of both healthy and at risk trial participants over many years .
Evidence supports a similar effect in children and young people