Table 2.
Low-fat and high-quality fat diets in type 2 diabetes mellitus.
| Authors (Year) Study Type |
Studies/Participants (N) Average Duration of Follow-Up (Years) |
Population | Diet Type Compared | Findings: T2DM Control (HbA1c/HOMA-IR/FPG/Need for Antidiabetic Drugs/Glycemic Variability) |
|---|---|---|---|---|
| Brunerova et al. (2007) [70] RCT |
1/58 3 months |
T2DM and obese non-T2DM adults | High-fat diet enriched with MUFA vs. conventional diet | Decrease in HbA1c from 7.3 ± 0.4% to 6.6 ± 0.3% (p < 0.01) on high-fat diet enriched with MUFA vs. from 6.9 ± 0.6% to 6.5 ± 0.5% (p > 0.01) on conventional diet |
| Davis et al. (2009) [79] RTC |
1/105 1 year |
Overweight adults with T2DM | LCD vs. LFD | There was no significant change in HbA1C in either group. |
| Brehm et al. (2009) [74] Cohort study |
1/1124 1 year |
Overweight and obese T2DM adults | High-quality high-MUFA diet vs. HCD | Both diets were equally effective; no significant differences were shown |
| Iqbal et al. (2010) [80] RTC |
1/144 2 years |
Obese adults with T2DM | LCD vs. LFD | At month 6, LCD was associated with a clinically significant reduction in HbA1c of −0.5% (compared to −0.1% on LFD), but this was not sustained over time |
| Itsiopoulos et al. (2011) [68] RCT |
1/27 24 weeks |
Adults with TDM2. |
MED vs. no diet | HbA1c decreased from 7.1% (95% CI: 6.5–7.7) to 6.8% (95% CI: 6.3–7.3) (p = 0.012) on MED diet |
| Guldbrand et al. (2012) [81] Prospective randomized parallel trial |
1/61 2 years |
Adults with TDM2 | LFD vs. LCD | HbA1c LCD at 6 months −4.8 ± 8.3 mmol/mol, p = 0.004, at 12 months −2.2 ± 7.7 mmol/mol, p = 0.12; LFD at 6 months −0.9 ± 8.8 mmol/mol, p = 0.56) Insulin doses were reduced in the LCD group (0 months, LCD 42 ± 65 E, LFD 39 ± 51 E; 6 months, LCD 30 ± 47 E, LFD 38 ± 48 E; p = 0.046 for between-group change) |
| Lasa et al. (2014) [67] Parallel trial |
1/177 1 year |
Adults free of cardiovascular disease but with T2DM; the participants followed oral anti-diabetic treatments. Participants of the PREDIMED |
MED with olive oil vs. MED with nuts vs. LFD | The adiponectin/HOMA-IR (A/HOMA-IR) ratio was significantly increased in the MED with olive oil eatery group and the trend was observed in the MED with nut eatery group (p = 0.069) and the LFD group (p = 0.061). |
| Qian et al. (2016) [66] Systematic review and meta-analysis of RCT |
24/1460 Up to 3 years |
Adults with T2DM | High-MUFA diet vs. HCD | Reductions in fasting plasma glucose: WMD−0,57 mmol/l [95%CI−0.76,−0.39] on High-MUFA diet compared to HCD |
| Schwingshackl et al. (2017) [77] Network Meta-analysis, Randomized trials |
56/4937 3–48 months |
Adults with T2DM | LCD vs. LFD | LCD caused significantly greater reduction in HbA1c than LFD: (95% CI) −0.35 (−0.56/−0.14)% |
| Wang et al. (2018) [78] Prospective, Single-blind randomized controlled trial |
1/56 3 months |
Chinese T2DM adults | LCD vs. LFD | LCD caused significantly greater reduction in HbA1c than LFD: (95% CI) −0.63% vs. −0.31%, p < 0.05. |
Abbreviations: BMI—Body Mass Index; FPG—fasting plasma glucose, HbA1c—Glycated hemoglobin; HCD—high-carbohydrate diet; HOMA-IR—Homeostatic Model Assessment for Insulin Resistance; LCD—low-carbohydrate diet; MUFA—monounsaturated fatty acids; MED—Mediterranean diet; PUFA—polyunsaturated fatty acids; T2DM—type 2 diabetes mellitus; RCT—randomized controlled trial.