title: Weight Loss, Glycemic Control, and Cardiovascular Disease Risk Factors in Response to Differential Diet Composition in a Weight Loss Program in Type 2 Diabetes: A Randomized Controlled Trial Meat Consumption as a Risk Factor for Type 2 Diabetes Withdrawal of red meat from the usual diet reduces albuminuria and improves serum fatty acid profile in type 2 diabetes patients with macroalbuminuria. Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes A multicenter randomized controlled trial of a plant-based nutrition program to reduce body weight and cardiovascular risk in the corporate setting: the GEICO study A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. Intensive lifestyle changes for reversal of coronary heart disease. A Multicomponent Intervention Reduces Body Weight and Cardiovascular Risk at a GEICO Corporate Site Dietary patterns, meat intake, and the risk of type 2 diabetes in women. Toward improved management of NIDDM: A randomized, controlled, pilot intervention using a lowfat, vegetarian diet. Effectiveness of a low-fat vegetarian diet in altering serum lipids in healthy premenopausal women. Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus. Partly replacing meat protein with soy protein alters insulin resistance and blood lipids in postmenopausal women with abdominal obesity.
abstract: OBJECTIVE To test whether a weight loss program promotes greater weight loss , glycemic control , and improved cardiovascular disease risk factors compared with control conditions and whether there is a differential response to higher versus lower carbohydrate intake . RESEARCH DESIGN AND METHODS This r and omized controlled trial at two university medical centers enrolled 227 overweight or obese adults with type 2 diabetes and assigned them to parallel in-person diet and exercise counseling , with prepackaged foods in a planned menu during the initial phase , or to usual care ( UC ; two weight loss counseling sessions and monthly contacts ) . RESULTS Relative weight loss was 7.4 % ( 95 % CI 5.7–9.2 % ) , 9.0 % ( 7.1–10.9 % ) , and 2.5 % ( 1.3–3.8 % ) for the lower fat , lower carbohydrate , and UC groups ( P < 0.001 intervention effect ) . Glycemic control markers and triglyceride levels were lower in the intervention groups compared with UC group at 1 year ( fasting glucose 141 [ 95 % CI 133–149 ] vs. 159 [ 144–174 ] mg/dL , P = 0.023 ; hemoglobin A1c 6.9 % [ 6.6–7.1 % ] vs. 7.5 % [ 7.1–7.9 % ] or 52 [ 49–54 ] vs. 58 [ 54–63 ] mmol/mol , P = 0.001 ; triglycerides 148 [ 134–163 ] vs. 204 [ 173–234 ] mg/dL , P < 0.001 ) . The lower versus higher carbohydrate groups maintained lower hemoglobin A1c ( 6.6 % [ 95 % CI 6.3–6.8 % ] vs. 7.2 % [ 6.8–7.5 % ] or 49 [ 45–51 ] vs. 55 [ 51–58 ] mmol/mol ) at 1 year ( P = 0.008 ) . CONCLUSIONS The weight loss program result ed in greater weight loss and improved glycemic control in type 2 diabetes Disease risk factors identified in epidemiological studies serve as important public health tools , helping clinicians identify individuals who may benefit from more aggressive screening or risk-modification procedures  , allowing policymakers to prioritize intervention programs , and encouraging at-risk individuals to modify behavior and improve their health . These factors have been based primarily on evidence from cross-sectional and prospect i ve studies , as most do not lend themselves to r and omized trials . While some risk factors are not modifiable , eating habits are subject to change through both individual action and broader policy initiatives . Meat consumption has been frequently investigated as a variable associated with diabetes risk , but it has not yet been described as a diabetes risk factor . In this article , we evaluate the evidence supporting the use of  meat consumption as a clinical ly useful risk factor for type 2 diabetes , based on studies evaluating the risks associated with  meat consumption  as a categorical dietary characteristic ( i.e. , meat consumption versus no meat consumption ) , as a scalar variable ( i.e. , gradations of meat consumption ) , or as part of a broader dietary pattern BACKGROUND Replacement of red meat in the diet with chicken has reduced the urinary albumin excretion rate ( UAER ) and serum cholesterol in microalbuminuric type 2 diabetes patients . The effects of withdrawing red meat are unknown in the more advanced stages of diabetic nephropathy . OBJECTIVE Our objective was to assess the effects of replacing red meat in the usual diet ( UD ) with chicken ( CD ) and of consuming a lactovegetarian low-protein diet ( LPD ) on renal function , fatty acid , and lipid profile in macroalbuminuric type 2 diabetes patients . DESIGN A crossover controlled trial was conducted in 17 type 2 diabetes patients with macroalbuminuria ( 24-h UAER > or = 200 microg/min ) . Each patient followed the UD , CD , and LPD in a r and om order for 4 wk . After each diet , glomerular filtration rate , UAER , serum fatty acid , lipid profile , glycemic control , anthropometric indexes , and blood pressure were measured . RESULTS UAER [ median CD : 269.4 ( range : 111 - 1128 ) microg/min ; LPD : 229.3 ( 76.6 - 999.3 ) microg/min ; UD : 312.8 ( 223.7 - 1223.7 ) microg/min ; P < 0.01 ] and mean ( + /-SD ) non-HDL cholesterol ( CD : 3.92 + /- 0.99 mmol/L ; LPD : 3.92 + /- 0.93 mmol/L ; UD : 4.23 + /- 1.06 mmol/L ; P = 0.042 ) were lower after CD and LPD than after UD . Compared with the UD , an increase in serum total polyunsaturated fatty acids was also observed ( CD : 39.8 + /- 2.6 % ; LPD : 39.7 + /- 4.4 % ; UD : 37.3 + /- 3.1 % ; P = 0.029 ) . CONCLUSION In macroalbuminuric patients with type 2 diabetes , withdrawing red meat from the diet reduces the UAER Aims The aim of this study was to compare the effects of calorie-restricted vegetarian and conventional diabetic diets alone and in combination with exercise on insulin resistance , visceral fat and oxidative stress markers in subjects with Type 2 diabetes . Methods A 24-week , r and omized , open , parallel design was used . Seventy-four patients with Type 2 diabetes were r and omly assigned to either the experimental group ( n = 37 ) , which received a vegetarian diet , or the control group ( n = 37 ) , which received a conventional diabetic diet . Both diets were isocaloric , calorie restricted ( -500 kcal/day ) . All meals during the study were provided . The second 12 weeks of the diet were combined with aerobic exercise . Participants were examined at baseline , 12 weeks and 24 weeks . Primary outcomes were : insulin sensitivity measured by hyperinsulinaemic isoglycaemic clamp ; volume of visceral and subcutaneous fat measured by magnetic resonance imaging ; and oxidative stress measured by thiobarbituric acid reactive substances . Analyses were by intention to treat . Results Forty-three per cent of participants in the experimental group and 5 % of participants in the control group reduced diabetes medication ( P < 0.001 ) . Body weight decreased more in the experimental group than in the control group [ –6.2 kg ( 95 % CI –6.6 to –5.3 ) vs. –3.2 kg ( 95 % CI –3.7 to –2.5 ) ; interaction group × time P = 0.001 ] . An increase in insulin sensitivity was significantly greater in the experimental group than in the control group [ 30 % ( 95 % CI 24.5–39 ) vs. 20 % ( 95 % CI 14–25 ) , P = 0.04 ] . A reduction in both visceral and subcutaneous fat was greater in the experimental group than in the control group ( P = 0.007 and P = 0.02 , respectively ) . Plasma adiponectin increased ( P = 0.02 ) and leptin decreased ( P = 0.02 ) in the experimental group , with no change in the control group . Vitamin C , superoxide dismutase and reduced glutathione increased in the experimental group ( P = 0.002 , P < 0.001 and P = 0.02 , respectively ) . Differences between groups were greater after the addition of exercise training . Changes in insulin sensitivity and enzymatic oxidative stress markers correlated with changes in visceral fat . Conclusions A calorie-restricted vegetarian diet had greater capacity to improve insulin sensitivity compared with a conventional diabetic diet over 24 weeks . The greater loss of visceral fat and improvements in plasma concentrations of adipokines and oxidative stress markers with this diet may be responsible for the reduction of insulin resistance . The addition of exercise training further augmented the improved outcomes with the vegetarian diet Background / objectives : To determine the effects of a low-fat plant-based diet program on anthropometric and biochemical measures in a multicenter corporate setting .Subjects/ methods : Employees from 10 sites of a major US company with body mass index ⩾25 kg/m2 and /or previous diagnosis of type 2 diabetes were r and omized to either follow a low-fat vegan diet , with weekly group support and work cafeteria options available , or make no diet changes for 18 weeks . Dietary intake , body weight , plasma lipid concentrations , blood pressure and glycated hemoglobin ( HbA1C ) were determined at baseline and 18 weeks . Results : Mean body weight fell 2.9 kg and 0.06 kg in the intervention and control groups , respectively ( P<0.001 ) . Total and low-density lipoprotein ( LDL ) cholesterol fell 8.0 and 8.1 mg/dl in the intervention group and 0.01 and 0.9 mg/dl in the control group ( P<0.01 ) . HbA1C fell 0.6 percentage point and 0.08 percentage point in the intervention and control group , respectively (P<0.01).Among study completers , mean changes in body weight were −4.3 kg and −0.08 kg in the intervention and control groups , respectively ( P<0.001 ) . Total and LDL cholesterol fell 13.7 and 13.0 mg/dl in the intervention group and 1.3 and 1.7 mg/dl in the control group ( P<0.001 ) . HbA1C levels decreased 0.7 percentage point and 0.1 percentage point in the intervention and control group , respectively ( P<0.01 ) . Conclusions : An 18-week dietary intervention using a low-fat plant-based diet in a corporate setting improves body weight , plasma lipids , and , in individuals with diabetes , glycemic control BACKGROUND Low-fat vegetarian and vegan diets are associated with weight loss , increased insulin sensitivity , and improved cardiovascular health . OBJECTIVE We compared the effects of a low-fat vegan diet and conventional diabetes diet recommendations on glycemia , weight , and plasma lipids . DESIGN Free-living individuals with type 2 diabetes were r and omly assigned to a low-fat vegan diet ( n = 49 ) or a diet following 2003 American Diabetes Association guidelines ( conventional , n = 50 ) for 74 wk . Glycated hemoglobin ( Hb A(1c ) ) and plasma lipids were assessed at weeks 0 , 11 , 22 , 35 , 48 , 61 , and 74 . Weight was measured at weeks 0 , 22 , and 74 . RESULTS Weight loss was significant within each diet group but not significantly different between groups ( -4.4 kg in the vegan group and -3.0 kg in the conventional diet group , P = 0.25 ) and related significantly to Hb A(1c ) changes ( r = 0.50 , P = 0.001 ) . Hb A(1c ) changes from baseline to 74 wk or last available values were -0.34 and -0.14 for vegan and conventional diets , respectively ( P = 0.43 ) . Hb A(1c ) changes from baseline to last available value or last value before any medication adjustment were -0.40 and 0.01 for vegan and conventional diets , respectively ( P = 0.03 ) . In analyses before alterations in lipid-lowering medications , total cholesterol decreased by 20.4 and 6.8 mg/dL in the vegan and conventional diet groups , respectively ( P = 0.01 ) ; LDL cholesterol decreased by 13.5 and 3.4 mg/dL in the vegan and conventional groups , respectively ( P = 0.03 ) . CONCLUSIONS Both diets were associated with sustained reductions in weight and plasma lipid concentrations . In an analysis controlling for medication changes , a low-fat vegan diet appeared to improve glycemia and plasma lipids more than did conventional diabetes diet recommendations . Whether the observed differences provide clinical benefit for the macro- or microvascular complications of diabetes remains to be established . This trial was registered at clinical trials.gov as NCT00276939 CONTEXT The Lifestyle Heart Trial demonstrated that intensive lifestyle changes may lead to regression of coronary atherosclerosis after 1 year . OBJECTIVES To determine the feasibility of patients to sustain  intensive lifestyle changes  for a total of 5 years and the effects of these lifestyle changes ( without lipid-lowering drugs ) on coronary heart disease . DESIGN R and omized controlled trial conducted from 1986 to 1992 using a r and omized invitational design . PATIENTS Forty-eight patients with moderate to severe coronary heart disease were r and omized to an  intensive lifestyle change group  or to a  usual-care control group  , and 35 completed the 5-year follow-up quantitative coronary arteriography . SETTING Two tertiary care university medical centers . INTERVENTION Intensive lifestyle changes ( 10 % fat whole foods vegetarian diet , aerobic exercise , stress management training , smoking cessation , group psychosocial support ) for 5 years . MAIN OUTCOME MEASURES Adherence to intensive lifestyle changes , changes in coronary artery percent diameter stenosis , and cardiac events . RESULTS Experimental group patients ( 20 [ 71 % ] of 28 patients completed 5-year follow-up ) made and maintained comprehensive lifestyle changes for 5 years , whereas control group patients ( 15 [ 75 % ] of 20 patients completed 5-year follow-up ) made more moderate changes . In the experimental group , the average percent diameter stenosis at baseline decreased 1.75 absolute percentage points after 1 year ( a 4.5 % relative improvement ) and by 3.1 absolute percentage points after 5 years ( a 7.9 % relative improvement ) . In contrast , the average percent diameter stenosis in the control group increased by 2.3 percentage points after 1 year ( a 5.4 % relative worsening ) and by 11.8 percentage points after 5 years ( a 27.7 % relative worsening ) ( P=.001 between groups . Twenty-five cardiac events occurred in 28 experimental group patients vs 45 events in 20 control group patients during the 5-year follow-up ( risk ratio for any event for the control group , 2.47 [ 95 % confidence interval , 1.48 - 4.20 ] ) . CONCLUSIONS More regression of coronary atherosclerosis occurred after 5 years than after 1 year in the experimental group . In contrast , in the control group , coronary atherosclerosis continued to progress and more than twice as many cardiac events occurred Purpose . To determine whether a multicomponent nutrition intervention program at a corporate site reduces body weight and improves other cardiovascular risk factors in overweight individuals . Design . Prospect i ve clinical intervention study . Subjects/ Setting . Employees of the Government Employees Insurance Company ( GEICO ) ( N = 113 ) , aged 21 to 65 years , with a body mass index ≥ 25 kg/m2 and /or previous diagnosis of type 2 diabetes . Intervention . A 22-week intervention including a low-fat , vegan diet . Measures . Changes in body weight , anthropometric measures , blood pressure , lipid profile , and dietary intake . Analysis . Multivariate analyses of variance were calculated for clinical and nutrient measures , followed by univariate analyses of variance , to determine the significance of differences between groups in changes over time . Results . Intervention-group participants  experienced greater weight changes compared with control-group participants ( mean , – 5.1 [ SE , .6 ] kg vs. + .1 [ SE , .6 ] kg , p < .0001 ) , as well as greater changes in waist circumference ( mean , – 4.7 [ SE , .6 ] cm vs. + .8 [ SE , .6 ] cm , p < .0001 ) and waist : hip ratio ( mean , – .006 [ SE , .003 ] vs. + .014 [ SE , .005 ] , p = .0007 ) . Weight loss of 5 % of body weight was more frequently observed in the intervention group ( 48.5 % ) compared with the control group ( 11.1 % ) ( χ2[1 , N= 113 ] = 16.99 , p < .0001 ) . Conclusions . Among individuals volunteering for a 22-week worksite research study , an intervention using a low-fat , vegan diet effectively reduced body weight and waist circumference BACKGROUND Although obesity is the most important risk factor for type 2 diabetes , evidence is emerging that certain foods and dietary factors may be associated with diabetes . To examine the association between major dietary patterns and risk of type 2 diabetes mellitus in a cohort of women . METHODS We prospect ively assessed the associations between major dietary patterns  and  risk of type 2 diabetes in women .  Dietary information was collected in 1984 , 1986 , 1990 , and 1994 from 69,554 women aged 38 to 63 years without a history of diabetes , cardiovascular disease , or cancer in 1984 . We conducted factor analysis and identified 2 major dietary patterns : " prudent " and " Western . " We then calculated pattern scores for each participant and examined prospect ively the associations between dietary pattern scores and type 2 diabetes risks . RESULTS The prudent pattern was characterized by higher intakes of fruits , vegetables , legumes , fish , poultry , and whole grains , while the Western pattern included higher intakes of red and processed meats , sweets and desserts , french fries , and refined grains . During 14 years of follow-up , we identified 2699 incident cases of type 2 diabetes .  After adjusting for potential confounders , we observed a relative risk for diabetes of 1.49 ( 95 % confidence interval [ CI ] , 1.26 - 1.76 , P for trend , < .001 ) when comparing the highest to lowest quintiles of the Western pattern . Positive associations were also observed between type 2 diabetes and red meat and other processed meats . The relative risk for diabetes for every 1-serving increase in intake is 1.26 ( 95 % CI , 1.21 - 1.42 ) for red meat , 1.38 ( 95 % CI , 1.23 - 1.56 ) for total processed meats , 1.73 ( 95 % CI , 1.39 - 2.16 ) for bacon , 1.49 ( 95 % CI , 1.04 - 2.11 ) for hot dogs , and 1.43 ( 95 % CI , 1.22 - 1.69 ) for processed meats . CONCLUSION The Western pattern , especially a diet higher in processed meats , may increase the risk of type 2 diabetes in women OBJECTIVE To investigate whether glycemic and lipid control in patients with non-insulin-dependent diabetes ( NIDDM ) can be significantly improved using a low-fat , vegetarian ( vegan ) diet in the absence of recommendations regarding exercise or other lifestyle changes . METHODS Eleven subjects with NIDDM recruited from the Georgetown University Medical Center or the local community were r and omly assigned to a low-fat vegan diet ( seven subjects ) or a conventional low-fat diet ( four subjects ) . Two additional subjects assigned to the control group failed to complete the study . The diets were not design ed to be isocaloric . Fasting serum glucose , body weight , medication use , and blood pressure were assessed at baseline and biweekly thereafter for 12 weeks . Serum lipids , glycosylated hemoglobin , urinary albumin , and dietary macronutrients were assessed at baseline and 12 weeks . RESULTS Although the sample was intentionally small in accordance with the pilot study design , the 28 % mean reduction in fasting serum glucose of the experimental group , from 10.7 to 7.75 mmol/L ( 195 to 141 mg/dl ) , was significantly greater than the 12 % decrease , from 9.86 to 8.64 mmol/L ( 179 to 157 mg/dl ) , for the control group ( P < 0.05 ) . The mean weight loss was 7.2 kg in the experimental group , compared to 3 . 8 kg for the control group ( P < 0.005 ) . Of six experimental group subjects on oral hypoglycemic agents , medication use was discontinued in one and reduced in three . Insulin was reduced in both experimental group patients on insulin . No patient in the control group reduced medication use . Differences between the diet groups in the reductions of serum cholesterol and 24-h microalbuminuria did not reach statistical significance ; however , high-density lipoprotein concentration fell more sharply ( 0.20 mmol/L ) in the experimental group than in the control group ( 0.02 mmol/L ) ( P < 0.05 ) . CONCLUSION The use of a low-fat , vegetarian diet in patients with NIDDM was associated with significant reductions in fasting serum glucose concentration and body weight in the absence of recommendations for exercise . A larger study is needed for confirmation Few controlled trials have studied cholesterol-lowering diets in premenopausal women . None has examined the cholesterol-lowering effect of a low-fat vegetarian diet , which , in other population groups , leads to marked reductions in serum cholesterol concentrations and , in combination with other life-style changes , a regression of atherosclerosis . We tested the hypothesis that a low-fat , vegetarian diet significantly reduces serum total and low-density lipoprotein ( LDL ) cholesterol concentrations in premenopausal women . In a crossover design , 35 women , aged 22 to 48 , followed a low-fat vegetarian diet deriving approximately 10 % of energy from fat for 2 menstrual cycles . For 2 additional cycles , they followed their customary diet while also taking a " supplement " ( placebo ) pill .  Serum lipid concentrations were assessed at baseline and during each intervention phase . Mean serum LDL , high-density lipoprotein ( HDL ) , and total cholesterol concentrations decreased 16 . 9 % , 16.5 % , and 13.2 % , respectively , from baseline to the intervention diet phase ( p<0.001 ) , whereas mean serum triacylglycerol concentration increased 18.7 % ( p<0.01 ) . LDL/HDL ratio remained unchanged . Thus , in healthy premenopausal women , a low-fat vegetarian diet led to rapid and sizable reductions in serum total , LDL , and HDL cholesterol concentrations BACKGROUND The effect of increasing the intake of dietary fiber on glycemic control in patients with type 2 diabetes mellitus is controversial . METHODS In a r and omized , crossover study , we assigned 13 patients with type 2 diabetes mellitus to follow two diets , each for six weeks : a diet containing moderate amounts of fiber ( total , 24 g ; 8 g of soluble fiber and 16 g of insoluble fiber ) , as recommended by the American Diabetes Association ( ADA ) , and a high-fiber diet ( total , 50 g ; 25 g of soluble fiber and 25 g of insoluble fiber ) , containing foods not fortified with fiber ( unfortified foods ) . Both diets , prepared in a research kitchen , had the same macronutrient and energy content . We compared the effects of the two diets on glycemic control and plasma lipid concentrations . RESULTS Compliance with the diets was excellent . During the sixth week , the high-fiber diet , as compared with the the sixth week of the ADA diet , mean daily prepr and ial plasma glucose concentrations were 13 mg per deciliter [ 0.7 mmol per liter ] lower ( 95 percent confidence interval , 1 to 24 mg per deciliter [ 0.1 to 1.3 mmol per liter ] ; P=0.04 ) and mean median difference , daily urinary glucose excretion 1.3 g ( 0.23 ; 95 percent confidence interval , 0.03 to 1.83 g ; P= 0.008 ) . The high-fiber diet also lowered the area under the curve for 24-hour plasma glucose and insulin concentrations , which were measured every two hours , by 10 percent ( P=0.02 ) and 12 percent ( P=0.05 ) , respectively . The high-fiber diet reduced plasma total cholesterol concentrations by 6.7 percent ( P=0.02 ) , triglyceride concentrations by 10.2 percent ( P=0.02 ) , and very-low-density lipoprotein cholesterol concentrations by 12.5 percent ( P=0.01 ) . CONCLUSIONS A high intake of dietary fiber , particularly of the soluble type , above the level recommended by the ADA , improves glycemic control , decreases hyperinsulinemia , and lowers plasma lipid concentrations in patients with type 2 diabetes Increasing protein intake and soy consumption appear to be promising approaches to prevent metabolic syndrome ( MetS ) . However , the effect of soy consumption on insulin resistance , glucose homeostasis , and other characteristics of MetS is not frequently studied in humans . We aim ed to investigate the effects of a 4-wk , strictly controlled , weight-maintaining , moderately high-protein diet rich in soy on insulin sensitivity and other cardiometabolic risk factors . We performed a r and omized crossover trial of 2 4-wk diet periods in 15 postmenopausal women with abdominal obesity to test diets with 22 energy percent ( En% ) protein , 27 En% fat , and 50 En% carbohydrate . One diet contained protein of mixed origin ( mainly meat , dairy , and bread ) , and the other diet partly replaced meat with soy meat analogues and soy nuts containing 30 g/d soy protein . For our primary outcome , a frequently sample d intravenous glucose tolerance test ( FSIGT ) was performed at the end of both periods . Plasma total , LDL , and HDL cholesterol , triglycerides , glucose , insulin , and C-reactive protein were assessed , and blood pressure , arterial stiffness , and intrahepatic lipid content were measured at the start and end of both periods . Compared with the mixed-protein diet , the soy-protein diet result ed in greater insulin sensitivity [ FSIGT : insulin sensitivity , 34 ± 29 vs. 22 ± 17 (mU/L)(-1 ) · min(-1 ) , P = 0.048 ; disposition index , 4974 ± 2543 vs. 2899 ± 1878 , P = 0.038 ; n = 11 ] . Total cholesterol was 4 % lower after the soy-protein diet than after the mixed-protein diet ( 4.9 ± 0.7 vs. 5.1 ± 0.6 mmol/L , P = 0.001 ) , and LDL cholesterol was 9 % lower ( 2.9 ± 0.7 vs. 3.2 ± 0.6 mmol/L , P = 0.004 ; n = 15 ) . Thus , partly replacing meat with soy in a moderately high-protein diet has clear advantages regarding insulin sensitivity and total and LDL cholesterol . Therefore , partly replacing meat products with soy products could be important in preventing MetS. This trial was registered at clinical trials.gov as NCT01694056
target: Consumption of vegetarian diets is associated with improved glycemic control in type 2 diabetes .
background: INTRODUCTION Previous studies have suggested an association between vegetarian diets and improvements in glycemic control in diabetes , although this relationship is not well established .
  No meta- analysis of these studies has been performed .
  METHODS To conduct a systematic review and meta- analysis of controlled clinical trials examining the association between  vegetarian diets  and  glycemic control in type 2 diabetes .