Dietary strategies for patients with type 2 diabetes in the era of multi-approaches; review and results from the Dietary Intervention Randomized Controlled Trial (DIRECT). Clinical Efficacy of Two Hypocaloric Diets That Vary in Overweight Patients With Type 2 Diabetes Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial. A non-calorie-restricted low-carbohydrate diet is effective as an alternative therapy for patients with type 2 diabetes. A Randomized Controlled Trial of a Mini Low-Carbohydrate Diet and an Energy-Controlled Diet Among Japanese Patients With Type 2 Diabetes Comparison of a carbohydrate-free diet vs. fasting on plasma glucose, insulin and glucagon in type 2 diabetes. Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes--a randomized controlled trial. A randomised controlled trial of the effect of low fat diet advice on dietary response in insulin independent diabetic women Effect of energy restriction, weight loss, and diet composition on plasma lipids and glucose in patients with type 2 diabetes. Long-term effects of weight loss with a very-low carbohydrate, low saturated fat diet on flow mediated dilatation in patients with type 2 diabetes: A randomised controlled trial. A Very Low-Carbohydrate, Low–Saturated Fat Diet for Type 2 Diabetes Management: A Randomized Trial Effects of a Mediterranean-Style Diet on the Need for Antihyperglycemic Drug Therapy in Patients With Newly Diagnosed Type 2 Diabetes Effects of a low-fat diet compared with those of a high-monounsaturated fat diet on body weight, plasma lipids and lipoproteins, and glycemic control in type 2 diabetes. Low-Carbohydrate Diet and Type 2 Diabetes Risk in Japanese Men and Women: The Japan Public Health Center-Based Prospective Study Long-term effects of very low-carbohydrate and high-carbohydrate weight-loss diets on psychological health in obese adults with type 2 diabetes: randomized controlled trial. Comparative Study of the Effects of a 1-Year Dietary Intervention of a Low-Carbohydrate Diet Versus a Low-Fat Diet on Weight and Glycemic Control in Type 2 Diabetes Effects of a Diet Higher in Carbohydrate/Lower in Fat Versus Lower in Carbohydrate/Higher in Monounsaturated Fat on Postmeal Triglyceride Concentrations and Other Cardiovascular Risk Factors in Type 1 Diabetes
Dietary intervention is recognized as a key component in prevention and management of type 2 diabetes ( T2DM ) and the debate persists : which dietary strategy is most effective . In the Dietary Intervention R and omized Controlled Trial ( DIRECT ) 322 moderately obese participants were r and omized for 2 years to one of three diet groups : low-fat , Mediterranean and low-carbohydrate . Differential effects were observed in the sub-group of patients with T2DM at 24 months : participants r and omized to the Mediterranean diet , which had the highest intake of dietary fibers and unsaturated to saturated fat ratio , achieved greater significant improvements in fasting plasma glucose and insulin levels . Patients who were r and omized to the low-carbohydrate diet , which had the minimal intake of carbohydrates , achieved a significant reduction of hemoglobin A1C . Although improvements were observed in all groups , the low-fat diet was likely to be less beneficial in terms of glycemic control and lipid metabolism . Interpretation of results from different studies on dietary strategies may be complex since there is often no consistency in diet compositions , calorie restriction , intensity of intervention , dietary assessment or extent of adherence in the trial . Nevertheless , it seems that low fat restricted calorie diets are effective for weight loss and are associated with some metabolic benefits ; however , some recent trials have shown that low carbohydrate diets are as efficient in inducing weight loss and in some metabolic measures such as serum triglycerides and HDL-cholesterol may be even superior to low fat diets . When addressing the issue of diet quality rather than quantity applying the glycemic index may have some added benefits . Furthermore special features of the Mediterranean diet have apparent additional favorable effects for patients with T2DM Approximately 80 % of patients with type 2 diabetes are overweight/obese ( 1 ) , and weight loss is the mainstay of treatment for these individuals . However , there is growing controversy as to whether reduced-fat or reduced-carbohydrate diets are best suited for this purpose , and results ( 2–8 ) in nondiabetic subjects suggest that lower carbohydrate diets are similarly or more efficacious in improving weight , triglycerides , and HDL cholesterol . There are no published r and omized studies evaluating the role of dietary macronutrients with respect to weight loss and cardiovascular risk improvement in patients with type 2 diabetes . Thus , we r and omized diet-treated patients with type 2 diabetes to hypocaloric diets , moderately restricted in either carbohydrate or fat , to determine whether weight loss or metabolic improvement differed as a function of macronutrient composition . A total of 29 patients with diet-treated type 2 diabetes were recruited from the San Francisco Bay area . All subjects gave written informed consent . Inclusion criteria included BMI 27–36 kg/m2 , fasting plasma glucose concentration 7.2–8.3 mmol/l , no use of antihyperglycemic medications , and stable weight for 3 months . Subjects on anti-hypertensive or cholesterol-lowering drugs or aspirin were allowed to continue their medications . Insulin-mediated glucose uptake was quantified by a modification ( 9 ) of the insulin suppression test as originally described ( 10 ) and vali date d ( 11 ) . In this test , a 180-min infusion of somatostatin ( 0.27 μg/m2 per min ) , insulin ( 25 mU/m2 per min ) , BACKGROUND Few well-controlled studies have comprehensively examined the effects of very-low-carbohydrate diets on  type 2 diabetes ( T2D ) . OBJECTIVE We compared the effects of a very-low-carbohydrate , high-unsaturated fat , low-saturated fat ( LC ) diet with a high-carbohydrate , low-fat ( HC ) diet on glycemic control and cardiovascular disease risk factors in T2D after 52 wk . DESIGN In this r and omized controlled trial that was conducted in an outpatient research clinic , 115 obese adults with T2D [ mean ± SD age : 58 ± 7 y ; body mass index ( in kg/m(2 ) ) : 34.6 ± 4.3 ; glycated hemoglobin ( HbA1c ) : 7.3 ± 1.1 % ; duration of diabetes : 8 ± 6 y ] were r and omly assigned to consume either a hypocaloric LC diet [ 14 % of energy as carbohydrate ( carbohydrate < 50 g/d ) , 28 % of energy as protein , and 58 % of energy as fat ( < 10 % saturated fat ) ] or an energy-matched HC diet [ 53 % of energy as carbohydrate , 17 % of energy as protein , and 30 % of energy as fat ( < 10 % saturated fat ) ] combined with supervised aerobic and resistance exercise ( 60 min ; 3 d/wk ) . Outcomes were glycemic control assessed with use of measurements of HbA1c , fasting blood glucose , glycemic variability assessed with use of 48-h continuous glucose monitoring , diabetes medication , weight , blood pressure , and lipids assessed at baseline , 24 , and 52 wk . RESULTS Both groups achieved similar completion rates ( LC diet : 71 % ; HC diet : 65 % ) and mean ( 95 % CI ) reductions in weight [ LC diet : -9.8 kg ( -11.7 , -7.9 kg ) ; HC diet : -10.1 kg ( -12.0 , -8.2 kg ) ] , blood pressure [ LC diet : -7.1 ( -10.6 , -3.7)/-6.2 ( -8.2 , -4.1 ) mm Hg ; HC diet : -5.8 ( -9.4 , -2.2)/-6.4 ( -8.4 , -4.3 ) mm Hg ] , HbA1c [ LC diet : -1.0 % ( -1.2 % , -0.7 % ) ; HC diet : -1.0 % ( -1.3 % , -0.8 % ) ] , fasting glucose [ LC diet : -0.7 mmol/L ( -1.3 , -0.1 mmol/L ) ; HC diet : -1.5 mmol/L ( -2.1 , -0.8 mmol/L ) ] , and LDL cholesterol [ LC diet : -0.1 mmol/L ( -0.3 , 0.1 mmol/L ) ; HC diet : -0.2 mmol/L ( -0.4 , 0.03 mmol/L ) ] ( P-diet effect ≥ 0.10 ) . Compared with the HC-diet group , the LC-diet group achieved greater mean ( 95 % CI ) reductions in the diabetes medication score [ LC diet : -0.5 arbitrary units ( -0.7 , -0.4 arbitrary units ) ; HC diet : -0.2 arbitrary units ( -0.4 , -0.06 arbitrary units ) ; P = 0.02 ] , glycemic variability assessed by measuring the continuous overall net glycemic action-1 [ LC diet : -0.5 mmol/L ( -0.6 , -0.3 mmol/L ) ; HC diet : -0.05 mmol/L ( -0.2 , -0.1 mmol/L ) ; P = 0.003 ] , and triglycerides [ LC diet : -0.4 mmol/L ( -0.5 , -0.2 mmol/L ) ; HC diet : -0.01 mmol/L ( -0.2 , 0.2 mmol/L ) ; P = 0.001 ] and greater mean ( 95 % CI ) increases in HDL cholesterol [ LC diet : 0.1 mmol/L ( 0.1 , 0.2 mmol/L ) ; HC diet : 0.06 mmol/L ( -0.01 , 0.1 mmol/L ) ; P = 0.002 ] . CONCLUSIONS Both diets achieved substantial weight loss and reduced HbA1c and fasting glucose . The LC diet , which was high in unsaturated fat and low in saturated fat , achieved greater improvements in the lipid profile , blood glucose stability , and reductions in diabetes medication requirements , suggesting an effective strategy for the optimization of T2D management . This trial was registered at www.anzctr.org.au as ACTRN12612000369820 OBJECTIVE Although caloric restriction is a widely used intervention to reduce body weight and insulin resistance , many patients are unable to comply with such dietary therapy for long periods . The clinical effectiveness of low-carbohydrate diets was recently described in a position statement of Diabetes UK and a scientific review conducted by the American Diabetes Association . However , r and omised trials of dietary interventions in Japanese patients with type 2 diabetes are scarce . Therefore , the aim of this study was to examine the effects of a non-calorie-restricted , low-carbohydrate diet in Japanese patients unable to adhere to a calorie-restricted diet . METHODS The enrolled patients were r and omly allocated to receive a conventional calorie-restricted diet or low-carbohydrate diet . The patients received consultations every two months from a registered dietician for six months . We compared the effects of the two dietary interventions on glycaemic control and metabolic profiles . RESULTS The HbA1c levels decreased significantly from baseline to six months in the low-carbohydrate diet group ( baseline 7.6±0.4 % , six months 7.0±0.7 % , p=0.03 ) but not in the calorie-restricted group ( baseline 7.7±0.6 % , six months 7.5±1.0 % , n.s . ) , ( between-group comparison , p=0.03 ) . The patients in the former group also experienced improvements in their triglyceride levels , without experiencing any major adverse effects or a decline in the quality of life . CONCLUSION Our findings suggest that a low-carbohydrate diet is effective in lowering the HbA1c and triglyceride levels in patients with type 2 diabetes who are unable to adhere to a calorie-restricted diet Background Low-carbohydrate diets have been shown to effectively improve the metabolic status of patients with type 2 diabetes mellitus . However , patients may find it challenging to maintain a strict low-carbohydrate diet . The objective of this study was to determine if a one-meal , low-carbohydrate diet is as effective in improving metabolic status as a conventional , energy-restricted diet among patients with type 2 diabetes mellitus . Methods In this 12-week r and omized controlled study , the primary endpoint was differences in the changes of plasma glycosylated hemoglobin ( HbA1c ) levels between the two experimental groups . Since the two groups had differences in body weight , body mass index , and waist circumference , propensity score matching was used to assess HbA1c outcomes via cohort pairs according to age , sex , body weight , HbA1c level , and waist circumference . Results There were no differences in the changes in HbA1c between the two groups ( P = 0.95 ) . In addition , there were no differences in the changes in glycated albumin , 1,5-anhydroglucitol , lipid profile , body weight , waist circumference , and fat mass between the two groups . The mini low-carbohydrate diet group had an increased protein intake ( P = 0.0085 ) , as compared with the control group . However , neither group showed changes in their Diabetes Treatment Satisfaction Question naire score . Conclusion Either diet would be effective for improving the metabolic status of this study population OBJECTIVE Hyperglycemia improves when patients with type 2 diabetes are placed on a weight-loss diet . Improvement typically occurs soon after diet implementation . This rapid response could result from low fuel supply ( calories ) , lower carbohydrate content of the weight-loss diet , and /or weight loss per se . To differentiate these effects , glucose , insulin , C-peptide and glucagon were determined during the last 24 h of a 3-day period without food ( severe calorie restriction ) and a calorie-sufficient , carbohydrate-free diet . RESEARCH DESIGN Seven subjects with untreated type 2 diabetes were studied . A r and omized-crossover design with a 4-week washout period between arms was used . METHODS Results from both the calorie-sufficient , carbohydrate-free diet and the 3-day fast were compared with the initial st and ard diet consisting of 55 % carbohydrate , 15 % protein and 30 % fat . RESULTS The overnight fasting glucose concentration decreased from 196 ( st and ard diet ) to 160 ( carbohydrate-free diet ) to 127 mg/dl ( fasting ) . The 24 h glucose and insulin area responses decreased by 35 % and 48 % on day 3 of the carbohydrate-free diet , and by 49 % and 69 % after fasting . Overnight basal insulin and glucagon remained unchanged . CONCLUSIONS Short-term fasting dramatically lowered overnight fasting and 24 h integrated glucose concentrations . Carbohydrate restriction per se could account for 71 % of the reduction . Insulin could not entirely explain the glucose responses . In the absence of carbohydrate , the net insulin response was 28 % of the st and ard diet . Glucagon did not contribute to the metabolic adaptations observed OBJECTIVE This study sought to examine the effects of a 3-month programme of dietary advice to restrict carbohydrate intake compared with reduced-portion , low-fat advice in obese subjects with poorly controlled Type 2 diabetes . RESEARCH DESIGN AND METHODS One hundred and two patients with Type 2 diabetes were recruited across three centres and r and omly allocated to receive group education and individual dietary advice .  Weight , glycaemic control , lipids and blood pressure were assessed at baseline and 3 months . Dietary quality was assessed at the end of study . RESULTS Weight loss was greater in the low-carbohydrate ( LC ) group ( -3.55 + /- 0.63 , mean + /- sem ) vs. -0.92 + /- 0.40 kg , P = 0.001 ) and cholesterol : high-density lipoprotein ( HDL ) ratio improved ( -0.48 + /- 0.11 vs. -0.10 + /- 0.10 , P = 0.01 ) . However , relative saturated fat intake was greater ( 13.9 + /- 0.71 vs. 11.0 + /- 0.47 % of dietary intake , P < 0.001 ) , although absolute intakes were moderate . CONCLUSIONS Carbohydrate restriction was an effective method of achieving short-term weight loss compared with st and ard advice , but this was at the expense of an increase in relative saturated fat intake Summary Type 2 ( insulin independent ) diabetic women were r and omly allocated to receive advice for low fat diets or low carbohydrate diets . By 24 h weighed dietary intakes before and after a mean interval of six months , patients in the low fat group had reduced their fat intake from 41 % to 31 % of total energy , while carbohydrate percentage of total energy intake increased from 38 % to 46 % . Percentage energy intake from fat and carbohydrate in the control group remained unchanged . Body weight fell in both groups , especially for patients in the low fat group who were obese ( weight/height2 ⩾ 28 kg/m2 ) . Mean plasma glucose , HbA1 , and triglycerides were unchanged . Mean plasma total cholesterol fell significantly in the low fat group compared with the controls ( p < 0.001 ) , but there was no significant difference in the small reduction of high density lipoprotein cholesterol observed in both groups . Thus , adherence to low fat diets occurred without deterioration of diabetes and with benefit for weight and total cholesterol OBJECTIVE To determine the optimal diet for improving glucose and lipid profiles in obese patients with type 2 diabetes during moderate energy restriction . RESEARCH DESIGN AND METHODS A total of 35 free-living obese patients with type 2 diabetes were assigned to one of three 1,600 kcal/day diets for 12 weeks . The diets were high carbohydrate ( 10 % fat , 4 % saturated ) , high monounsaturated fat ( MUFA ) ( 32 % fat , 7 % saturated ) , or high saturated fat ( SFA ) ( 32 % fat , 17 % saturated ) . RESULTS Diet composition did not affect the magnitude of weight loss , with subjects losing an average of 6.6 + /- 0.9 kg . Energy restriction and weight loss result ed in reductions in fasting plasma glucose ( -14 % ) , insulin ( -27 % ) , GHb ( -14 % ) , and systolic ( -7 % ) and diastolic blood pressure ( -10 % ) levels and the glucose response area ( -17 % ) independent of diet composition . Diet composition did affect the lipoprotein profile . LDL was 10 % and 17 % lower with the high-carbohydrate and high-MUFA diets , respectively , whereas no change was observed with the high-SFA diet ( P < 0.001 for effect of diet ) . HDL was transiently reduced on the high-carbohydrate diet at weeks 1 , 4 , and 8 , whereas higher fat consumption maintained these levels . The total cholesterol : HDL ratio , although significantly reduced on the high-MUFA diet ( P < 0.01 ) , was not different from the other two diets after adjustment for baseline differences . CONCLUSIONS Energy restriction , independent of diet composition , improves glycemic control ; however , reducing SFA intake by replacing SFA with carbohydrate or MUFA reduces LDL maximally during weight loss and to a greater degree than has been shown in weight-stable studies BACKGROUND AND AIMS Very-low carbohydrate diets can improve glycaemic control in patients with type 2 diabetes ( T2DM ) . However , compared to traditional higher carbohydrate , low fat ( HighCHO ) diets , they have been associated with impaired endothelial function ( measured by flow mediated dilatation [ FMD ] ) that is possibly related to saturated fat . This study aim ed to examine the effects of a 12-month hypocaloric very-low carbohydrate , low saturated fat ( LowCHO ) diet compared to an isocaloric HighCHO diet . METHODS One hundred and fifteen obese patients with T2DM ( age:58.4 ± 0.7 [ SEM ] yr , BMI : 34.6 ± 0.4 kg/m(2 ) , HbA1c:7.33 [ 56.3 mmol/mol ] ± 0.10 % ) were r and omised to consume an energy restricted LowCHO diet ( Carb : Pro : Fat : Sat-Fat 14:28:58 : < 10 % energy ; n = 58 ) or isocaloric HighCHO diet ( 53:17:30 : < 10 % ; n = 57 ) whilst undertaking exercise ( 60 min , 3/wk ) . Bodyweight , HbA1c and FMD were assessed . RESULTS Seventy eight participants completed the intervention ( LowCHO = 41 , HighCHO = 37 ) . Both groups experienced similar reductions in weight and HbA1c ( -10.6 ± 0.7 kg , -1.05 ± 0.10 % ; p < 0.001 time , p ≥ 0.48 time × diet ) . FMD did not change ( p = 0.11 time , p = 0.20 time × diet ) . CONCLUSIONS In patients with obesity and T2DM  , HighCHO diet and LowCHO diet have similar effects on endothelial function OBJECTIVE To comprehensively compare the effects of a very low-carbohydrate , high – unsaturated/low – saturated fat diet ( LC ) with those of a high – unrefined carbohydrate , low-fat diet ( HC ) on glycemic control and cardiovascular disease ( CVD ) risk factors in type 2 diabetes ( T2DM ) . RESEARCH DESIGN AND METHODS Obese adults ( n = 115 , BMI 34.4 ± 4.2 kg/m2 , age 58 ± 7 years ) with T2DM were r and omized to a hypocaloric LC diet ( 14 % carbohydrate [ < 50 g/day ] , 28 % protein , and 58 % fat [ < 10 % saturated fat ] ) or an energy-matched HC diet ( 53 % carbohydrate , 17 % protein , and 30 % fat [ < 10 % saturated fat ] ) combined with structured exercise for 24 weeks . The outcomes measured were as follows : glycosylated hemoglobin ( HbA1c ) , glycemic variability ( GV ; assessed by 48-h continuous glucose monitoring ) , antiglycemic medication changes ( antiglycemic medication effects score [ MES ] ) , and blood lipids and pressure . RESULTS A total of 93 participants completed 24 weeks . Both groups achieved similar completion rates ( LC 79 % , HC 82 % ) and weight loss ( LC −12.0 ± 6.3 kg , HC −11.5 ± 5.5 kg ) ; P ≥ 0.50 . Blood pressure ( −9.8/−7.3 ± 11.6/6.8 mmHg ) , fasting blood glucose ( −1.4 ± 2.3 mmol/L ) , and LDL cholesterol ( −0.3 ± 0.6 mmol/L ) decreased , with no diet effect ( P ≥ 0.10 ) . LC achieved greater reductions in triglycerides ( −0.5 ± 0.5 vs. −0.1 ± 0.5 mmol/L ) , MES ( −0.5 ± 0.5 vs. −0.2 ± 0.5 ) , and GV indices ; P  ≤ 0.03 . LC induced greater HbA1c reductions ( −2.6 ± 1.0 % [ −28.4 ± 10.9 mmol/mol ] vs. −1.9 ± 1.2 % [ −20.8 ± 13.1 mmol/mol ] ; P = 0.002 ) and HDL cholesterol ( HDL-C ) increases ( 0.2 ± 0.3 vs. 0.05 ± 0.2 mmol/L ; P = 0.007 ) in participants with the respective baseline values HbA1c > 7.8 % ( 62 mmol/mol ) and HDL-C < 1.29 mmol/L. CONCLUSIONS Both diets achieved substantial improvements for several clinical glycemic control and CVD risk markers . These improvements and reductions in GV and antiglycemic medication requirements were greatest with the LC compared with HC . This suggests an LC diet with low saturated fat may be an effective dietary approach for T2DM management if effects are sustained beyond 24 weeks Context Mediterranean-style diets improve control of coronary risk factors and hyperglycemia , but few direct comparisons of the diet with other st and ard diets have been done . Contribution In this r and omized clinical trial , patients with newly diagnosed type 2 diabetes who were assigned to a low-carbohydrate , Mediterranean-style diet had better glycemic control and were less likely to need oral antihyperglycemic therapy than patients assigned to a low-fat diet . Caution The trial was unblinded , and dietary intake was self-reported . Implication A low-carbohydrate , Mediterranean-style diet seems to be preferable to a low-fat diet for glycemic control in patients with newly diagnosed type 2 diabetes . The Editors The p and emic of type 2 diabetes is an enormous public health problem , with 380 million cases worldwide projected by 2025 ( 1 , 2 ) . Lifestyle intervention studies ( 3 ) have demonstrated large reductions in risk for type 2 diabetes that remain after lifestyle counseling is stopped ( 4 , 5 ) . Despite this beneficial effect , the American Diabetes Association ( ADA ) recommends that patients with newly diagnosed type 2 diabetes be treated with pharmacotherapy as well as lifestyle changes ( 6 ) . The rationale for combination therapy is presumably that each form of treatment alone is imperfect . Lifestyle changes are often inadequate because patients do not lose weight or regain weight or their diabetes worsens independent of weight ( 6 ) . Pharmacotherapy also often fails with time ( 7 ) , and some drugs have associated cardiovascular and other risks ( 8 , 9 ) . For those reasons , lifestyle changes proven to be more effective than what is typically recommended would be welcome . For example , Mediterranean-style ( MED ) diets with a high proportion of monounsaturated fat provide cardiovascular benefits and increase insulin sensitivity ( 1012 ) , and the ADA recommends low-carbohydrate or low-fat , calorie-restricted diets for weight loss in overweight and obese patients with type 2 diabetes ( 13 ) . However , few direct , long-term comparisons of the 2 diets in patients with diabetes have been done ( 11 ) . We conducted a r and omized trial to compare the effectiveness , durability , and safety of a low-carbohydrate MED diet and a low-fat diet on glycemic control in patients with newly diagnosed type 2 diabetes . Methods We conducted the trial between January 2004 ( first patient enrolled ) and September 2008 ( end of follow-up of the last patient ) at the research center of the Diabetes Clinic of the Azienda Ospedaliera Universitaria , Second University of Naples , Naples , Italy , in accordance with the Declaration of Helsinki and with the institutional review board 's approval . Screening Phase We recruited men and women with newly diagnosed type 2 diabetes by ADA criteria who had never been treated with antihyperglycemic drugs from the clinical practice s of trial investigators and screened them for eligibility . Inclusion criteria were age 30 to 75 years , body mass index ( BMI ) greater than 25 kg/m2 , and hemoglobin A1c ( HbA1c ) level less than 11 % . Participants also had to be sedentary ( < 1 hour of physical activity per week ) with no evidence of participation in weight-reduction programs and with a stable weight ( 2 kg ) in the past 6 months . Exclusion criteria included pregnancy or breastfeeding , use of any investigational drug in the previous 3 months , use of agents affecting glycemic control ( such as systemic glucocorticoids and weight loss drugs ) , and any condition that might compromise adherence to diet regimens . To minimize the likelihood of including participants with late-onset type 1 diabetes , we screened c and i date s by testing for antibodies to glutamate decarboxylase and measuring fasting plasma C-peptides . We excluded patients with positive antibodies or C-peptide levels less than 0.25 pmol/L ( < 0.76 ng/L ) . We also excluded patients with abnormal laboratory test results , including liver enzyme levels ( alanine aminotransferase , aspartate aminotransferase , and alkaline phosphatase ) greater than 3 times the upper limit of normal and serum creatinine levels greater than 123.8 mol/L ( > 1.4 mg/dL ) . We required that participants successfully self-monitor their diet and physical activity over a 2-week run-in period . We provided dietary education during that time that emphasized the importance of eating a healthy diet and being physically active for both weight loss and improvement of glycemic control . Participants were also taught to prepare their own meals at home . We encouraged all individuals who smoked to quit and provided self-help material s , referral to local programs , or both , as appropriate . R and omization and Blinding After obtaining informed consent , we r and omly assigned patients to 1 of the 2 study diets by using a computer-generated r and om-number sequence ( simple r and omization ) . Allocation was concealed in sealed study folders that were held in a central , secured location until after informed consent was obtained . The nurses who scheduled the study visits did not have access to the r and omization list , and laboratory staff did not know the participants ' group assignments . Staff members involved in the intervention were aware of group assignments , but those who assessed achievement of the primary outcome were blinded to the intervention . Participants received no financial compensation or gifts . Dietary Interventions We r and omly assigned patients to a low-carbohydrate MED diet or to a low-fat diet . The MED diet was rich in vegetables and whole grains and low in red meat , which was replaced with poultry and fish . We restricted energy intake to 1500 kcal/d for women and 1800 kcal/d for men , with the goal of no more than 50 % of calories from complex carbohydrates , based on evidence that , in the context of a MED diet , a carbohydrate content less than 50 % of daily energy is more beneficial than higher content for weight loss and cardiovascular risk reduction ( 14 ) . The diet had no less than 30 % calories from fat . The main source of added fat was 30 to 50 g of olive oil . The low-fat diet was based on American Heart Association guidelines ( 15 ) ; it was rich in whole grains and restricted additional fats , sweets , and high-fat snacks . We restricted energy intake to 1500 kcal/d for women and 1800 kcal/d for men , with the goal of no more than 30 % of calories from fat and no more than 10 % of calories from saturated fat . Nutritionists and dietitians gave dietary advice to participants in both groups in monthly sessions in the first year and bimonthly sessions thereafter . Participants kept diet diaries after being instructed how to record their intake using food models as examples of portion size and using actual weights or amounts in terms of common measures ( such as cups , teaspoons , and dessert spoons ) . We assessed adherence to the diets by session attendance and review of the diaries . Nondietary Interventions Patients in both groups also received guidance on increasing their level of physical activity , mainly walking for a minimum of 30 minutes per day , but also swimming or aerobic ball games . The physical activity program relied heavily on home-based exercise with gradual progression toward a goal of 175 minutes of moderate-intensity physical activity per week . Although walking was encouraged , participants were allowed to choose other types of moderate-intensity physical activity , and programs were tailored on the basis of the results of a baseline physical fitness test and safety concerns . We asked all patients to record occupational , household , and leisure time physical activity . Outcomes We followed patients for 4 years to assess trial outcomes . The primary outcome measure was time to introduction of antihyperglycemic drug therapy . Trial investigators were responsible for initiating drug therapy by the following protocol . As suggested by the ADA for clinical evaluation and management of diabetic patients ( 16 ) , we measured HbA1c at baseline and every 3 months thereafter . Participants who had a HbA1c level greater than 7 % were given an additional 3 months to reinforce dietary guidance and physical activity ; if the HbA1c level remained greater than 7 % , a drug regimen was introduced . Participants with an HbA1c level greater than 7 % at baseline were counted as having experienced the primary outcome if they still had that level at first follow-up . Trial investigators were also responsible for initiating or titrating antihypertensive or lipid-lowering therapy . Secondary outcome measures were changes in weight ( including BMI and waist circumference ) , glycemic control ( HbA1c , glucose , serum insulin , and adiponectin levels and homeostasis model assessment of insulin sensitivity ) , coronary risk factors ( lipid levels and blood pressure ) , and medications and meeting ADA coronary risk factor goals ( HbA1c level < 7 % , blood pressure < 130/80 mm Hg , and low-density lipoprotein cholesterol level < 2.59 mmol/L [ < 100 mg/dL ] ) ( 16 ) . Participants were weighed without shoes and in lightweight clothing to the nearest 0.1 kg at baseline and every month . Height at baseline ( for calculation of BMI ) was measured to the nearest millimeter with the use of a wall-mounted stadiometer ( Seca , Hamburg , Germany ) . Waist circumference was measured halfway between the last rib and the iliac crest . We measured HbA1c levels with high-pressure liquid chromatography by using the fully automated Glycosylated Hemoglobin Analyzer System ( Bio-Rad , Hercules , California ) traceable to the Diabetes Control and Complications Trial reference method , with a reference range of 4.0 % to 6.0 % . Insulin sensitivity in the fasting state was assessed with homeostasis model assessment and calculated with the following formula , as described by Matthews and colleagues ( 17 ) : fasting plasma glucose (mmol/L)fasting serum insulin (U/mL)/25 . High scores indicate low insulin sensitivity ( insulin resistance ) . We assayed plasma insulin and adiponectin levels by radioimmunoassay , as described elsewhere ( 18 ) . We performed assays for serum BACKGROUND An important therapeutic goal for patients with type 2 diabetes is weight loss , which improves metabolic abnormalities . Ad libitum low-fat diets cause weight loss in nondiabetic population s. Compared with diets higher in monounsaturated fat , however , eucaloric low-fat diets may increase plasma triacylglycerol concentrations and worsen glycemic control in persons with type 2 diabetes . OBJECTIVE We investigated whether , in type 2 diabetes patients , an ad libitum low-fat diet would cause greater weight loss than would a high-monounsaturated fat diet and would do this without increasing plasma triacylglycerol concentrations or worsening glycemic control . DESIGN Eleven patients with type 2 diabetes were r and omly assigned to receive an ad libitum low-fat , high-carbohydrate diet or a high-monounsaturated fat diet , each for 6 wk . The diets offered contained 125 % of the estimated energy requirement to allow self- selection of food quantity . The response variables were body weight ; fasting plasma lipid , lipoprotein , glucose , glycated hemoglobin A(1c ) , and fructosamine concentrations ; insulin sensitivity ; and glucose disposal . RESULTS Body weight decreased significantly ( 1.53 kg ; P < 0.001 ) only with the low-fat diet .  Plasma total , LDL- , and HDL-cholesterol concentrations tended to decrease during both diets . There were no interaction effects between diet and the lipid profile response over time . Plasma triacylglycerol concentrations , glycemic control , and insulin sensitivity did not differ significantly between the 2 diets . CONCLUSION Contrary to expectations , the ad libitum , low-fat , high-fiber diet promoted weight loss in patients with type 2 diabetes without causing unfavorable alterations in plasma lipids or glycemic control Objective Evidence is sparse and contradictory regarding the association between low-carbohydrate diet score and type 2 diabetes risk , and no prospect i ve study examined the association among Asians , who consume greater amount of carbohydrate . We prospect ively investigated the association of low-carbohydrate diet score with type 2 diabetes risk . Methods Participants were 27,799 men and 36,875 women aged 45–75 years who participated in the second survey of the Japan Public Health Center-Based Prospect i ve Study and who had no history of diabetes .  Dietary intake was ascertained by using a vali date d food-frequency question naire , and low-carbohydrate diet score was calculated from total carbohydrate , fat , and protein intake . The scores for high animal protein and fat or for high plant protein and fat were also calculated . Odds ratios of self-reported , physician-diagnosed type 2 diabetes over 5-year were estimated by using logistic regression . Results During the 5-year period , 1191 new cases of type 2 diabetes were self-reported . Low-carbohydrate diet score for high total protein and fat was significantly associated with a decreased risk of type 2 diabetes in women ( P for trend < 0.001 ) ; the multivariable-adjusted odds ratio of type 2 diabetes for the highest quintile of the score were 0.63 ( 95 % confidence interval 0.46–0.84 ) , compared with those for the lowest quintile . Additional adjustment for dietary glycemic load attenuated the association ( odds ratio 0.75 , 95 % confidence interval 0.45–1.25 ) . When the score separated for animal and for plant protein and fat , the score for high animal protein and fat was inversely associated with type 2 diabetes in women , whereas the score for high plant protein and fat was not associated in both men and women . Discussion Low-carbohydrate diet was associated with decreased risk of type 2 diabetes in Japanese women and this association may be partly attributable to high intake of white rice . The association for animal-based and plant-based low-carbohydrate diet warrants further investigation BACKGROUND / OBJECTIVE Very low-carbohydrate , high-fat ( LC ) diets are used for type 2 diabetes ( T2DM ) management , but their effects on psychological health remain largely unknown . This study examined the long-term effects of an LC diet on psychological health . METHODS One hundred and fifteen obese adults [ age : 58.5 ± 7.1 years ; body mass index : 34.6 ± 4.3 kg m(-2 ) ; HbA1c : 7.3 ± 1.1 % ] with T2DM were r and omized to consume either an energy-restricted ( ~6 to 7 MJ ) , planned isocaloric LC or high-carbohydrate , low-fat ( HC ) diet , combined with a supervised exercise programme ( 3 days week(-1 ) ) for 1 year . Body weight , psychological mood state and well-being [ Profile of Mood States ( POMS ) , Beck Depression Inventory ( BDI ) and Spielberger State Anxiety Inventory ( SAI ) ] and diabetes-specific emotional distress [ Problem Areas in Diabetes ( PAID ) Question naire ] and quality of life [ QoL Diabetes-39 ( D-39 ) ] were assessed . RESULTS Overall weight loss was 9.5 ± 0.5 kg ( mean ± SE ) , with no difference between groups ( P = 0.91 time × diet ) . Significant improvements occurred in BDI , POMS ( total mood disturbance and the six subscales of anger-hostility , confusion-bewilderment , depression-dejection , fatigue-inertia , vigour-activity and tension-anxiety ) , PAID ( total score ) and the D-39 dimensions of diabetes control , anxiety and worry , sexual functioning and energy and mobility , P < 0.05 time . SAI and the D-39 dimension of social burden remained unchanged ( P ≥ 0.08 time ) . Diet composition had no effect on the responses for the outcomes assessed ( P ≥ 0.22 time × diet ) . CONCLUSION In obese adults with T2DM , both diets achieved substantial weight loss and comparable improvements in QoL , mood state and affect . These results suggest that either an LC or HC diet within a lifestyle modification programme that includes exercise training improves psychological well-being OBJECTIVE To compare the effects of a 1-year intervention with a low-carbohydrate and a low-fat diet on weight loss and glycemic control in patients with type 2 diabetes . RESEARCH DESIGN AND METHODS This study is a r and omized clinical trial of 105 overweight adults with type 2 diabetes . Primary outcomes were weight and A1C . Secondary outcomes included blood pressure and lipids . Outcome measures were obtained at 3 , 6 , and 12 months . RESULTS The greatest reduction in weight and A1C occurred within the first 3 months . Weight loss occurred faster in the low-carbohydrate group than in the low-fat group ( P = 0.005 ) , but at 1 year a similar 3.4 % weight reduction was seen in both dietary groups . There was no significant change in A1C in either group at 1 year . There was no change in blood pressure , but a greater increase in HDL was observed in the low-carbohydrate group ( P = 0.002 ) . CONCLUSIONS Among patients with type 2 diabetes , after 1 year a low-carbohydrate diet had effects on weight and A1C similar to those seen with a low-fat diet . There was no significant effect on blood pressure , but the low-carbohydrate diet produced a greater increase in HDL cholesterol OBJECTIVE To compare the effects of a eucaloric diet higher in carbohydrate/lower in fat versus lower in carbohydrate/higher in monounsaturated fat on postmeal triglyceride ( TG ) concentrations and other cardiovascular disease risk factors in nonobese subjects with type 1 diabetes and in good glycemic control . RESEARCH DESIGN AND METHODS In a parallel group design study , 30 subjects were r and omly assigned and completed one of the two eucaloric diets . Assessment s included : BMI , blood pressure , A1C , plasma lipids , and markers of oxidation , thrombosis , and inflammation . At 6 months , subjects were hospitalized for 24 h to measure plasma TG excursions . RESULTS There were no significant differences between groups other than decreased plasminogen activator inhibitor 1 ( PAI-1 ) levels and weight gain in the lower-carbohydrate/higher – monounsaturated fat group . During the 24-h testing , the lower-carbohydrate/higher – monounsaturated fat group had a lower plasma TG profile . CONCLUSIONS A diet lower in carbohydrate/higher in monounsaturated fat could offer an appropriate choice for nonobese type 1 diabetic individuals with good metabolic and weight control
There is low to high ( majority moderate ) certainty for small improvements of unclear clinical importance in plasma glucose , triglycerides , and HDL concentrations favoring low-carbohydrate food at half of the prespecified time points .
There was little to no difference in LDL concentration or any of the secondary outcomes ( body weight , waist circumference , blood pressure , quality of life ) in response to either of the diets ( very-low- to high-certainty evidence ) .
Conclusions Currently available data provide low- to moderate-certainty evidence that dietary carbohydrate restriction to a maximum of 40 % yields slightly better metabolic control of uncertain clinical importance than reduction in fat to a maximum of 30 % in people with T2D .
Background It remains uncertain which diet is best for people with type 2 diabetes ( T2D ) .
Objective We compared the effects of dietary carbohydrate restriction with fat restriction on markers of metabolic syndrome and quality of life in people with T2D .