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Cited by 821Diet and metabolism studiesNutritional Studies and DietDiabetes Treatment and Management

Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes

Open access
Ajala, Olubukola, English, Patrick, Pinkney, Jonathan·2013·The American Journal of Clinical Nutrition
DOI 10.3945/ajcn.112.042457
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Abstract

Background There is evidence that reducing blood glucose concentrations, inducing weight loss, and improving the lipid profile reduces cardiovascular risk in people with type 2 diabetes.Objective We assessed the effect of various diets on glycemic control, lipids, and weight loss.Design We conducted searches of PubMed, Embase, and Google Scholar to August 2011. We included randomized controlled trials (RCTs) with interventions that lasted ≥6 mo that compared low-carbohydrate, vegetarian, vegan, low-glycemic index (GI), high-fiber, Mediterranean, and high-protein diets with control diets including low-fat, high-GI, American Diabetes Association, European Association for the Study of Diabetes, and low-protein diets.Results A total of 20 RCTs were included (n = 3073 included in final analyses across 3460 randomly assigned individuals). The low-carbohydrate, low-GI, Mediterranean, and high-protein diets all led to a greater improvement in glycemic control [glycated hemoglobin reductions of -0.12% (P = 0.04), -0.14% (P = 0.008), -0.47% (P < 0.00001), and -0.28% (P < 0.00001), respectively] compared with their respective control diets, with the largest effect size seen in the Mediterranean diet. Low-carbohydrate and Mediterranean diets led to greater weight loss [-0.69 kg (P = 0.21) and -1.84 kg (P < 0.00001), respectively], with an increase in HDL seen in all diets except the high-protein diet.Conclusion Low-carbohydrate, low-GI, Mediterranean, and high-protein diets are effective in improving various markers of cardiovascular risk in people with diabetes and should be considered in the overall strategy of diabetes management.

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Claims the paper makes

0 of 29 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    An increase in HDL was seen in all diets except the high-protein diet.

    “with an increase in HDL seen in all diets except the high-protein diet.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Low-GI diets increased HDL (WMD +0.05 mmol/L; 95% CI 0.02, 0.07; P<0.0001).

    “Low-GI diets were effective in increasing HDL (WMD: +0.05 mmol/L, 95% CI: 0.02, 0.07 mmol/L; P , 0.0001)”
    Quote in the paperSubstantial claim
  • Findingown data

    Low-GI diets did not significantly reduce LDL (WMD -0.07 mmol/L; 95% CI -0.16, 0.02; P=0.15).

    “but the reductions in LDL and triglycerides were not significant compared with those for control diets (for low-GI diets, WMD: 20.07 mmol/L; 95% CI: 20.16, 0.02 mmol/L; P = 0.15”
    Quote in the paperNot a substantial claim
  • Findingcitation

    Two variations of the Mediterranean diet compared with a low-fat diet in 1224 participants with high cardiovascular risk (about two-thirds with diabetes) showed a greater reduction in triglycerides in the group consuming the Mediterranean diet with nut supplementation.

    “Salas-Salvado ´et al (31) compared 2 variations of the Mediterranean diet with a low-fat diet in 1224 participants with high cardiovascular risk.Approximately two-thirds of participants had diabetes, and the major significant finding was a greater reduction in triglycerides in the group who consumed the Mediterranean diet with nut supplementation.”
    Quote in the paperNot a substantial claim
  • Findingown data

    High-protein diets showed no benefit for weight loss compared with control diets (WMD +0.44 kg; 95% CI -0.96, 1.84; P=0.54).

    “Data pooled from 2 studies showed no benefit of high-protein diet compared with control diets for achieving weight loss (WMD: +0.44 kg; 95% CI: -0.96, 1.84; P = 0.54).”
    Quote in the paperSubstantial claim
  • May combine two claims. 36
  • The quote only partly states this claim. 13
  • Classified as probably not a substantial claim. 12

  • May combine two claims.

    Findingown data

    Low-carbohydrate, low-GI, and Mediterranean diets led to significant lipid profile improvements, with up to a 4-10% increase in HDL, 1-4% reduction in LDL, and 9% reduction in triglycerides.

    “Low-carbohydrate, low-GI ,and Mediterranean diets led to significant improvements in the lipid profile with up to a 4-10% increase in HDL (4% in Mediterranean, 5% in low-GI, and 10% in low-carbohydrate diets), 1-4% reduction in LDL (1% in lowcarbohydrate, 3% in low-GI, and 4% in Mediterranean diets), and 9% reduction in triglycerides.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Mediterranean diets significantly reduced triglycerides (WMD -0.21 mmol/L; 95% CI -0.29, -0.14; P<0.00001).

    “The Mediterranean diet significantly reduced triglycerides (WMD: 20.21 mmol/L; 95% CI: 20.29, 20.14 mmol/L; P , 0.00001)”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Mediterranean diets were more effective for weight loss than control diets (WMD -1.84 kg; 95% CI -2.54, -1.15; P<0.00001).

    “The Mediterranean diet was more effective in achieving weight loss that control diets were with a WMD in weight loss of 21.84 kg (95% CI: 2.54, 21.15 kg; P , 0.00001).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The 16 studies in the quantitative analysis were randomized controlled trials with interventions lasting from 6 months to 4 years.

    “The 16 studies included in the quantitative analysis were RCTs with dietary interventions that ranged from 6 mo (30, 32, 34, 35, 42) to 4 y (36).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    A vegan diet compared with a low-fat ADA diet produced significantly greater reductions in total cholesterol, LDL, and HbA1c in the vegan group after 74 weeks.

    “Barnard et al (36) compared a vegan diet with the low-fat ADA diet and showed a significantly greater reduction in total cholesterol, LDL, and Hb A 1c in the vegan group after 74 wk.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The review included 20 randomized controlled trials with 3073 participants in final analyses out of 3460 randomly assigned individuals.

    “A total of 20 RCTs were included (n = 3073 included in final analyses across 3460 randomly assigned individuals).”
    • Also stated in: § Participants · plain
      “The 20 studies included 3460 patients with final analyses in 3073 patients.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    The search identified 1801 records from electronic databases and 64 additional records from other sources.

    “A total of 1801 records were identified from the initial electronic search, with an additional 64 records from other sources (references of reviews and other articles).”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Mediterranean diets led to greater weight loss (1.84 kg) compared with control diets.

    “The Mediterranean diet was more effective in achieving weight loss that control diets were with a WMD in weight loss of 21.84 kg (95% CI: 2.54, 21.15 kg; P , 0.00001).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingcitation

    A low-carbohydrate diet compared with a low-fat diet in 146 patients (45 with diabetes) showed no significant difference in weight loss or glycemic control in the whole group.

    “Yancy et al (32) compared a low-carbohydrate diet with a lowfat diet in 146 patients, 45 of whom had diabetes.There was no significant difference in the amount of weight loss or glycemic control in the whole group (41).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Six studies were excluded from meta-analyses; four had no other studies for comparison within their subgroup, and two included participants with and without diabetes without separate data for those with diabetes.

    “Six studies were excluded from meta-analyses; 4 of these studies had no other studies for comparison within their subgroup (5,(28)(29)(30), and 2 studies included participants with and without diabetes with no separate data provided for subjects with diabetes (31,41).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    An 18-month analysis showed an advantage of vegetarian diets for glycemic control and lipid profile but not for weight loss.

    “Additional analysis at 18 mo (29) showed an advantage of vegetarian diets in terms of glycemic control and lipid profile but not in weight loss (48).”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-carbohydrate diets significantly decreased HbA1c compared with other diets (WMD -0.12%; 95% CI -0.24, -0.00; P=0.04; I2=75%).

    “There was a significant decrease in the percentage of Hb A 1c in subjects who consumed low-carbohydrate compared with other diets (WMD: 20.12%; 95% CI: 20.24%, 20.00%; P = 0.04, I 2 = 75%).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingcitation

    Two studies compared a high-protein diet with low-protein and high-carbohydrate diets.

    “2 studies (40, 44) compared a high-protein diet with low-protein and highcarbohydrate diets, respectively.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-GI diets led to a greater improvement in glycemic control (HbA1c reduction of 0.14%) compared with control diets.

    “Data from the 3 studies that compared low-GI with other diets (34,38,39) showed a 20.14% decrease in Hb A 1c in subjects who consumed low-GI compared with control diets (95% CI: 20.23%, 20.03%; P = 0.008, I 2 = 80%).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    A vegetarian diet compared with an EASD diet produced greater weight loss and reduced diabetes medication requirements in the vegetarian arm.

    “A similar-sized study (30) that compared a vegetarian diet with the EASD diet showed greater weight loss and reduced requirements for diabetes medication in the vegetarian arm.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-carbohydrate diets led to a greater improvement in glycemic control (HbA1c reduction of 0.12%) compared with control diets.

    “The lowcarbohydrate, low-GI, Mediterranean, and high-protein diets all led to a greater improvement in glycemic control [glycated hemoglobin reductions of 20.12% (P = 0.04), 20.14% (P = 0.008), 20.47% (P , 0.00001), and 20.28% (P , 0.00001), respectively] compared with their respective control diets”
    • Also stated in: § Glycemic control · plain
      “There was a significant decrease in the percentage of Hb A 1c in subjects who consumed low-carbohydrate compared with other diets (WMD: 20.12%; 95% CI: 20.24%, 20.00%; P = 0.04, I 2 = 75%).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-carbohydrate diets showed no significant difference in weight loss compared with control diets (WMD -0.69 kg; 95% CI -1.77, 0.39; P=0.21).

    “There was no significant difference in weight loss when low-carbohydrate diets were compared with control diets (WMD: 20.69 kg; 95% CI: 21.77, 0.39 kg; P = 0.21).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-GI diets significantly decreased HbA1c compared with control diets (WMD -0.14%; 95% CI -0.23, -0.03; P=0.008; I2=80%).

    “Data from the 3 studies that compared low-GI with other diets (34,38,39) showed a 20.14% decrease in Hb A 1c in subjects who consumed low-GI compared with control diets (95% CI: 20.23%, 20.03%; P = 0.008, I 2 = 80%).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    All participants were at least 18 years old, and all but one study included both sexes.

    “All participants were $18 y old, and all but one study (35) included both sexes.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-carbohydrate diets did not significantly reduce LDL (WMD -0.03 mmol/L; 95% CI -0.12, 0.07; P=0.57).

    “with no significant reduction in LDL (WMD: 20.03 mmol/L; 95% CI: 20.12, 0.07 mmol/L; P = 0.57)”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Low-GI diets did not significantly reduce triglycerides (WMD -0.01 mmol/L; 95% CI -0.04, 0.03; P=0.69).

    “for control diets, WMD: 20.01 mmol/L; 95% CI: 20.04, 0.03 mmol/L; P = 0.69).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    High-protein diets had no significant effects on LDL, triglycerides, or HDL compared with control diets.

    “High-protein diets had no effects on markers of the lipid profile (LDL WMD: 20.16 mmol/L; 95% CI: 20.41, 0.09 mmol/L; P = 0.22; triglyceride WMD: 20.11 mmol/L; 95% CI: 20.56, 0.33 mmol/L; P = 0.61; HDL WMD: +0.01 mmol/L; 95% CI: 20.08, 0.10 mmol/L; P = 0.89).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Low-carbohydrate diets led to greater weight loss (0.69 kg) compared with control diets, but the difference was not statistically significant (P=0.21).

    “Low-carbohydrate and Mediterranean diets led to greater weight loss [20.69 kg (P = 0.21) and 21.84 kg (P , 0.00001), respectively]”
    • Also stated in: § Weight loss · plain
      “There was no significant difference in weight loss when low-carbohydrate diets were compared with control diets (WMD: 20.69 kg; 95% CI: 21.77, 0.39 kg; P = 0.21).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The 20 included studies comprised 3460 patients, with 3073 in final analyses.

    “The 20 studies included 3460 patients with final analyses in 3073 patients.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Four included studies enrolled patients with and without diabetes; one provided separate glycemic control data for the diabetic group, and another was included in quantitative analysis despite lacking separate diabetic data because more than 80% of its population had diabetes.

    “Four of the studies (31)(32)(33)41) included patients with and without diabetes, and one of these studies (32) provided data on the change in glycemic control in the diabetic group, and another study (33) was included in quantitative analysis despite not having separate data for the diabetic group because .80% of the study population had diabetes.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Mediterranean diets significantly decreased HbA1c compared with other diets (WMD -0.47%; 95% CI -0.64, -0.30; P<0.00001; I2=82%).

    “The 3 studies that compared Mediterranean with other diets (35)(36)(37) showed a WMD in Hb A 1c of 20.47% in favor of the Mediterranean diet (95% CI: 20.64%, 20.30%; P , 0.00001, I 2 = 82%).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Studies comparing high-carbohydrate with high-MUFA diets and high-fiber with low-fat diets showed no significant benefit.

    “No significant benefit was shown in studies that compared highcarbohydrate with high-MUFA diets (5) and high-fiber with lowfat diets (28).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingcitation

    Other studies compared vegan with ADA diets, vegetarian with EASD diets, high-carbohydrate with high-MUFA diets, and high-fiber with low-fat diets.

    “Other studies compared vegan with ADA diets (29), vegetarian with EASD diets (30), highcarbohydrate with high-MUFA diets (5), and high-fiber with low-fat diets (28).”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    High-protein diets significantly decreased HbA1c compared with other diets (WMD -0.28%; 95% CI -0.38, -0.18; P<0.00001; I2=60%).

    “Data pooled from 2 studies that compared high-protein with other diets (40,44) showed a significant decrease in the percentage of Hb A 1c in subjects who consumed high-protein diets (WMD: 20.28%; 95% CI: 20.38%, 20.18%; P , 0.00001, I 2 = 60%).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    High-protein diets led to a greater improvement in glycemic control (HbA1c reduction of 0.28%) compared with control diets.

    “Data pooled from 2 studies that compared high-protein with other diets (40,44) showed a significant decrease in the percentage of Hb A 1c in subjects who consumed high-protein diets (WMD: 20.28%; 95% CI: 20.38%, 20.18%; P , 0.00001, I 2 = 60%).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Low-GI diets resulted in lower HbA1c and higher HDL but no significant difference in weight loss.

    “Low-GI diets resulted in a lower Hb A 1c and higher HDL but no significant difference in weight loss (34,38,39).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The meta-analysis found differences in HbA1c between low-carbohydrate and other diets, low-GI and other diets, Mediterranean and other diets, and high-protein and other diets.

    “Forest plots that show differences in Hb A 1c between low-carbohydrate and other diets (A), low-GI and other diets (B), Mediterranean and other diets (C), and high-protein and other diets (D).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Studies comparing a high-carbohydrate diet with a high-MUFA diet and a high-fiber diet with a low-fat diet showed no significant differences in weight, glycemic control, and lipid profile.

    “The studies that compared a diet high in carbohydrates to one high in MUFAs and high-fiber with low-fat diets showed no significant differences in weight, glycemic control, and lipid profile (5,28).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [5] Brehm, 2009, One-year comparison of a high monounsaturated fat diet with a high-carbohydrate diet in type 2 diabetes, Diabetes Care source

      Not checked in the free run.

    • cites [28] Milne, 1994, Long-term comparison of three dietary prescriptions in the treatment of NIDDM, Diabetes Care source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Neither of the two high-protein studies showed significant differences in weight, glycemic control, or lipids, but pooled data showed significantly lower HbA1c in the high-protein-diet group.

    “Neither study showed any significant differences in weight, glycemic control, or lipids, but pooled data showed significantly lower Hb A 1c concentrations in the high-protein-diet group.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    A vegetarian diet compared with an EASD diet produced significant reductions in diabetes medication, greater weight loss, and increased insulin sensitivity in the vegetarian arm but no significant difference in HbA1c.

    “Kahleova et al (30) randomly assigned a similar number of participants to receive either a vegetarian or EASD diet and showed significant reductions in diabetes medication, greater weight loss, and increased insulin sensitivity in the vegetarian arm but no significant difference in Hb A 1c .”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    The three trials in the meta-analysis compared a Mediterranean diet with a conventional diet and ADA diet and showed better glycemic control, greater weight loss, and a more favorable lipid profile in the Mediterranean-diet arm.

    “The 3 trials included in the meta-analysis compared a Mediterranean diet with a conventional diet (ie, no change to the current diets of participants) and ADA diet (35)(36)(37) and showed better glycemic control, greater weight loss, and a more-favorable lipid profile in the Mediterranean-diet arm.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Weight loss and reduced total calorie intake are important for achieving good glycemic control.

    “It is clear that weight loss and reduced total calorie intake are important in the obtainment of good glycemic control (3)(4)(5)(6)(7)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites (3)(4)(5)(6)(7)

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    Most included trials reported the method of random assignment (all but 3), 10 reported allocation concealment, and 6 used intention-to-treat analysis.

    “Except for 3 studies (8,35,37), all other studies reported the method of random assignment, 10 studies reported the method of allocation concealment, and 6 studies were analyzed on an intention-to-treat basis (7,32,34,36,39,40).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    A recent review by Wheeler et al. also found that low-carbohydrate diets appeared to improve glycemic control markers with nonsignificant improvements in lipoproteins.

    “A recently published review by Wheeler et al (47) that looked at literature between 2001 and 2010 also showed that lowcarbohydrate diets appeared to improve markers of glycemic control with nonsignificant improvements in lipoproteins.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [47] Wheeler, 2012, Macronutrients, food groups, and eating patterns in the management of diabetes: a systematic review of the literature, 2010, Diabetes Care source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Several trials have shown that carbohydrate restriction, low-GI diets, and Mediterranean diets can improve glycemic control and weight loss over the long term.

    “Several trials (8)(9)(10) have documented the potential benefits of carbohydrate restriction and low-glycemic index (GI) and Mediterranean diets on glycemic control and weight loss that are maintained long term (9,(11)(12)(13)(14).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites (8)(9)(10)

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    • cites (9,(11)(12)(13)(14)

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  • May combine two claims.

    Interpretationreasoning

    Low-carbohydrate diets appeared to provide superior weight loss, glycemic control, and lipid profile compared with low-fat diets.

    “The low-carbohydrate diets appeared to provide superior weight loss, glycemic control, and lipid profile compared with low-fat diets”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    Meta-analysis was performed for each dietary subgroup only when data from more than one trial were available and of sufficient quality.

    “A meta-analysis was undertaken for each dietary-intervention subgroup when appropriate (16 of 20 trials) with Revman 5 software (Cochrane Information Management System) when data were available for more than one trial and were of sufficient quality.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Systematic reviews and meta-analyses indicate that low-GI, high-fiber, and Mediterranean diets improve glucose metabolism.

    “Systematic reviews and meta-analyses have shown that low-GI, high-fiber, and Mediterranean diets improve glucose metabolism (16)(17)(18).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites (16)(17)(18)

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Most authorities recommend carbohydrate intake of 50-60% of total energy and total fat intake of 30% or less of energy.

    “Most of these authorities recommend a carbohydrate intake of 50-60% of total energy intake, total fat intake #30% of energy (with moderate polyunsaturated fat and restriction of saturated and trans fat intake).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites (19)(20)(21)(22)(23)(24)(25)(26)(27)

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Modifying macronutrient amounts can improve glycemic control, weight, and lipids in people with diabetes.

    “This review provides evidence that modifying the amount of macronutrients can improve glycemic control, weight, and lipids in people with diabetes.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    An important difference between the Mediterranean and ADA diets is likely to be the content of MUFAs, which has been shown to affect lipid profile, insulin sensitivity, and postprandial glucose concentrations.

    “An important difference between the Mediterranean and ADA diets is likely to be the content of MUFAs, which has been shown to have an impact on the lipd profile (54,55), insulin sensitivity (56-58), and postprandial glucose concentrations (59).”
    Quote in the paperNot a substantial claim0 of 6 sources checked
    • cites [54] Rodríguez-Villar, 2004, Comparison of a high-carbohydrate and a high-monounsaturated fat, olive oil-rich diet on the susceptibility of LDL to oxidative modification in subjects with type 2 diabetes mellitus, Diabet Med source

      Not checked in the free run.

    • cites [55] Garg, 1994, Effects of varying carbohydrate content of diet in patients with non-insulin-dependent diabetes mellitus, JAMA source

      Not checked in the free run.

    • cites [56] Esposito, 2004, Effect of a Mediterranean-style diet on endothelial dysfunction and markers of vascular inflammation in the metabolic syndrome: a randomized trial, JAMA source

      Not checked in the free run.

    • cites [57] Schwenke, 2005, Insulin resistance, low-fat diets, and low-carbohydrate diets: time to test new menus, Curr Opin Lipidol source

      Not checked in the free run.

    • cites [58] Lara-Castro, 2004, Diet, insulin resistance, and obesity: zoning in on data for Atkins dieters living in South Beach, J Clin Endocrinol Metab source

      Not checked in the free run.

    • cites [59] O’Keefe, 2008, Dietary strategies for improving post-prandial glucose, lipids, inflammation, and cardiovascular health, J Am Coll Cardiol source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Anderson et al. performed a meta-analysis comparing low-GI with high-GI diets and showed significant benefits for glycemic control and lipid profile.

    “Anderson et al (51) performed a meta-analysis that compared low-GI with high-GI diets and showed significant benefits in terms of glycemic control and lipid profile.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [51] Anderson, 2004, Carbohydrate and fiber recommendations for individuals with diabetes: a quantitative assessment and meta-analysis of the evidence, J Am Coll Nutr source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    There is a suggestion that vegan and vegetarian diets might improve glycemic control and induce weight loss.

    “Therefore, there is a suggestion that vegan and vegetarian diets might be beneficial in improving glycemic control and inducing weight loss.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    The impact of high-protein diets on glycemic control might have been due to previous suggestions that protein affects appetite suppression and insulin sensitivity.

    “This impact on glycemic control might have been due to previous suggestions that protein has effects on appetite suppression (63) and insulin sensitivity (64)(65)(66)(67)(68).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [63] Weigle, 2005, A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations, Am J Clin Nutr source

      Not checked in the free run.

    • cites (64)(65)(66)(67)(68)

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The HbA1c reduction with low-GI diets was only 0.14% and might not have been clinically relevant.

    “The Hb A 1c reduction was only 0.14% and might not have been clinically relevant.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Our conclusion regarding the Mediterranean diet is similar to that of Esposito et al., which showed improved glycemic control, and Kastorini et al., whose meta-analysis showed an association between the Mediterranean diet and improved lipid profile and lower blood glucose.

    “Our conclusion regarding the Mediterranean diet is similar to that in a review by Esposito et al (60), which showed improved glycemic control, and Kastorini et al (61), whose meta-analysis showed an association between the Mediterranean diet and improved lipid profile and lower blood glucose.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [60] Esposito, 2010, Prevention and control of type 2 diabetes by Mediterranean diet: A systematic review, Diabetes Res Clin Pract source

      Not checked in the free run.

    • cites [61] Kastorini, 2011, The effect of Mediterranean diet on metabolic syndrome and its components: a meta-analysis of 50 studies and 534,906 individuals, J Am Coll Cardiol source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The studies in Anderson et al. included subjects with type 1 diabetes and children, enrolled a mean of 14 participants, and averaged 33 days per trial, making it difficult to extrapolate findings to older T2D populations and impossible to predict if benefits would be sustained over time.

    “However, these studies included subjects those with type 1 diabetes and children and enrolled a mean of just 14 participants for an average of 33 d per trial, which made it difficult to extrapolate the findings to the prevalently older T2D population and made it impossible to predict if these benefits would be sustained over time.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The findings of Wheeler et al. were similar to ours, with only small differences in glycemic control between low- and high-GI and other diets.

    “The findings of Wheeler et al (47) were similar to ours with only little differences in glycemic control between low-and high-GI and other diets.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [47] Wheeler, 2012, Macronutrients, food groups, and eating patterns in the management of diabetes: a systematic review of the literature, 2010, Diabetes Care source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    The review assessed risk of bias for each included study.

    “The review of judgments of authors about each risk-of-bias item is presented as percentages across all included studies.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    This possibility might be of particular relevance when interpreting the effect of low-carbohydrate diets.

    “This possibility might be of particular relevance when the effect of low-carbohydrate diets is interpreted.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Weight change independently affects glycemic control and lipid profile.
55 of 55

  • The paper relies on this without support.

    There is limited evidence on the optimal dietary approach to control hyperglycemia in type 2 diabetes.

    “However, there is limited evidence on the optimal dietary approach to control hyperglycemia in type 2 diabetes (T2D) 4 .”

  • The paper relies on this without support.

    The ideal proportion of carbohydrate, fat, and protein that should be recommended remains unclear.

    “but the ideal proportion of the 3 main food components (carbohydrate, fat, and protein) that should be recommended remains unclear.”

  • The paper relies on this without support.

    There is insufficient evidence to justify current recommendations for macronutrient intake in type 2 diabetes.

    “However, there is insufficient evidence to justify these recommendations.”

  • The paper relies on this without support.

    No systematic review or meta-analysis has compared the effects of different categories of dietary intervention on glycemic control, weight loss, and lipids in type 2 diabetes.

    “To our knowledge, there is no systematic review or meta-analysis that has compared the effects of different categories of dietary intervention on glycemic control, weight loss, and lipids in T2D.”

  • The paper relies on this without support.

    Weight change independently affects glycemic control and lipid profile.

    “Another major confounder was the independent effect of weight change on the other measured variables (glycemic control and lipid profile).”
5 of 5

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • A low-GI trial is cited as a low-carbohydrate trial

    Minor

    Study 39 is counted among the pooled low-carbohydrate studies, but the paper describes its intervention as low GI with an ADA-diet control.

  • Vegan trial is assigned the Mediterranean trial's citation

    Minor

    The text calls the vegan-diet study Barnard et al (36), but elsewhere assigns the vegan comparison to reference 29; reference 36 is identified as a Mediterranean-diet trial.

  • Yancy study is given Samaha's reference number

    Minor

    The text identifies Yancy et al as study 32, whereas the trial summary identifies study 32 as Samaha.

  • Study 30 is listed as both included and excluded from meta-analysis

    Minor

    The duration summary identifies study 30 among the studies in the quantitative analysis, while the exclusions section lists it among studies excluded from meta-analyses.

4 of 4

Cites

Flagged first, then by citations

1 of the 79 references couldn’t be matched to a known paper.

Research works printed but not linked: 1

  1. 1999, Guidelines for the nutritional management of diabetes mellitus in the new millennium: a position statement by the Canadian Diabetes Association, Can J Diabetes Care, 23, 56

Cited by

Sorted by citations

Related

Authors
Ajala, O., English, P., & Pinkney, J.
Affiliations
  • Peninsula College of Medicine and Dentistry (GB)
  • Derriford Hospital (GB)
ORCID
Venue
The American Journal of Clinical Nutrition
Publisher
Elsevier BV
Published
2013-03
Volume
97
Issue
3
Pages
505-516
ISSN
0002-9165 (ISSN-L)
DOI
10.3945/ajcn.112.042457
OpenAlex
W2099244083
Semantic Scholar
e4d5824fa11cd712a63bb7bf472781a82f8d88f3
Cited by
821
References
79
Citations by year
2026: 23 · 2025: 28 · 2024: 43 · 2023: 46 · 2022: 64 · 2021: 60 · 2020: 120 · 2019: 58 · 2018: 78 · 2017: 71 · 2016: 70 · 2015: 60 · 2014: 66 · 2013: 34
FWCI
8.44
Type
journal article
Language
en
Open access
Licence
Locations
  • American Journal of Clinical Nutrition (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Physiology › Diet and metabolism studies
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutritional Studies and Diet
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes Treatment and Management
Keywords
type 2 diabetes, dietary intervention, glycemic control, HbA1c, low-carbohydrate diet, Mediterranean diet, low glycemic index diet, high-protein diet, weight loss, lipid profile, HDL cholesterol, cardiovascular risk, vegetarian diet, vegan diet, high-fiber diet
MeSH terms
Blood Glucose, Energy Intake, Cardiovascular Diseases, Diabetes Mellitus, Type 2, Dietary Carbohydrates, Dietary Fats, Dietary Fiber, Dietary Proteins, Humans, Lipids, Risk Factors, Diet, Vegetarian, Weight Loss, Randomized Controlled Trials as Topic, Diet, Fat-Restricted, Diet, Protein-Restricted, Glycemic Index, Diet, Mediterranean, Diet, Carbohydrate-Restricted

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-06.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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