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. 2022 Jun 7;31(2):100–122. doi: 10.7570/jomes22009

Table 1.

Summary of findings for effects of carbohydrate-restricted diets and intermittent fasting in adults with overweight/obesity

Outcome Illustrative comparative risk* (95% CI) No. of participants Quality of the evidence (GRADE)

Assumed risk(control) Corresponding risk

Intervention Mean difference
mLCD
Body weight (kg, follow-up: 8–24 wk) –3.74 –4.77 –1.03 (–1.68 to –0.39) 3,660 (24 studies) Low
Body mass index (kg/m2, follow-up: 8–24 wk) –1.5 –1.73 –0.23 (–0.46 to 0.00) 2,750 (15 studies) Very low
Waist circumference (cm, follow-up: 12–24 wk) –4.83 –5.48 –0.65 (–1.16 to –0.14) 2,340 (15 studies) Moderate
Fat mass (kg, follow-up: 12–24 wk) –2.92 –3.36 –0.44 (–0.83 to –0.04) 2,080 (14 studies) Moderate
Fat-free mass (kg, follow-up: 12–24 wk) 0.17 0.00 –0.17 (–0.49 to 0.14) 1,139 (10 studies) Low
Fat mass (%, follow-up: 12–24 wk) –2.7 –2.61 0.09 (–0.45 to 0.64) 445 (4 studies) Low
Systolic blood pressure (mmHg, follow-up: 8–24 wk) –4.0 –4.56 –0.56 (–1.69 to 0.56) 2,612 (19 studies) Low
Diastolic blood pressure (mmHg, follow-up: 8–24 wk) –2.5 –3.19 –0.69 (–1.39 to 0.01) 2,615 (19 studies) Low
Triglyceride (mg/dL, follow-up: 8–24 wk) –11.8 –25.56 –13.76 (–19.78 to –7.74) 2,896 (24 studies) Low
LDL-C (mg/dL, follow-up: 12–24 wk) –4.6 –2.31 2.29 (–0.41 to 4.99) 2,721 (21 studies) Very low
HDL-C (mg/dL, follow-up: 8–24 wk) –0.8 1.81 2.61 (1.34 to 3.89) 2,448 (20 studies) Moderate
HbA1c (%, follow-up: 8–24 wk) –0.2 –0.40 –0.20 (–0.39 to –0.01) 739 (8 studies) Low
Fasting insulin (μU/mL, follow-up: 12–24 wk) –0.9 –1.84 –0.94 (–1.73 to –0.16) 1,855 (13 studies) Moderate
Fasting glucose (mg/dL, follow-up: 8–24 wk) –3.1 –3.42 –0.32 (–1.23 to 0.58) 2,143 (17 studies) Low
C-reactive protein (mg/L, follow-up: 8–24 wk) –0.1 –0.44 –0.34 (–0.67 to –0.01) 1,391 (11 studies) Low
Adiponectin (μg/mL, follow-up: 8–24 wk) 0.2 0.65 0.45 (0.15 to 0.76) 1,356 (8 studies) Moderate
VLCD
Body weight (kg, follow-up: 8–24 wk) –3.75 –7.42 –3.67 (–4.84 to –2.51) 1,266 (14 studies) Moderate
Body mass index (kg/m2, follow-up: 8–24 wk) –1.0 –2.88 –1.88 (–3.11 to –0.65) 388 (5 studies) Moderate
Waist circumference (cm, follow-up: 8–24 wk) –4.7 –8.81 –4.11 (–8.70 to 0.49) 233 (2 studies) Low
Fat mass (kg, follow-up: 8–24 wk) –4.8 –7.81 –3.01 (–6.29 to 0.27) 168 (3 studies) Low
Fat-free mass (kg, follow-up: 8–24 wk) –0.3 –1.35 –1.05 (–1.75 to –0.35) 168 (3 studies) Low
Fat mass (%, follow-up: 8–24 wk) –1.45 –3.33 –1.88 (–2.87 to –0.89) 515 (4 studies) Moderate
Systolic blood pressure (mmHg, follow-up: 8–24 wk) –3.0 –4.97 –1.97 (–3.68 to –0.25) 506 (9 studies) Moderate
Diastolic blood pressure (mmHg, follow-up: 8–24 wk) –2.1 –2.78 –0.68 (–1.79 to 0.44) 906 (9 studies) Low
Triglyceride (mg/dL, follow-up: 8–24 wk) –11.9 –33.23 –21.33 (–30.46 to –12.21) 1,059 (13 studies) Low
LDL-C (mg/dL, follow-up: 8–24 wk) –5.1 2.42 7.52 (3.34 to 11.70) 1,023 (12 studies) Moderate
HDL-C (mg/dL, follow-up: 8–24 wk) 0.0 4.30 4.30 (1.79 to 6.82) 1,058 (13 studies) Low
HbA1c (%, follow-up: 8–24 wk) –0.15 –0.42 –0.27 (–0.50 to –0.03) 354 (6 studies) Low
Fasting insulin (μU/mL, follow-up: 8–24 wk) –1.55 –2.92 –1.37 (–2.89 to 0.15) 603 (6 studies) Low
Fasting glucose (mg/dL, follow-up: 8–24 wk) –2.9 –3.34 –0.44 (–2.66 to 1.78) 730 (9 studies) Low
C-reactive protein (mg/L, follow-up: 8–24 wk) –0.2 –0.83 –0.63 (–1.41 to 0.15) 371 (5 studies) Low
Adiponectin (μg/mL, follow-up: 8–24 wk) 0.4 1.15 0.75 (0.29 to 1.21) 181 (2 studies) Low
Intermittent fasting§
Body weight (kg, follow-up: 12–24 wk) –3.62 –4.84 –1.22 (–3.49 to 1.05) 554 (8 studies) Very low
Body mass index (kg/m2, follow-up: 12–24 wk) –1.46 –1.95 –0.49 (–1.13 to 0.14) 380 (5 studies) Low
Waist circumference (cm, follow-up: 12–24 wk) –2.28 –4.23 –1.95 (–4.09 to 0.2) 180 (3 studies) Very low
Fat mass (kg, follow-up: 12–24 wk) –1.1 –1.46 –0.36 (–0.87 to 0.16) 540 (8 studies) Very low
Fat-free mass (kg, follow-up: 12–24 wk) –3.7 –4.37 –0.67 (–1.95 to 0.62) 540 (8 studies) Very low
Fat mass (%, follow-up: 12–24 wk) –0.9 –0.63 0.27 (–0.48 to 1.01) 142 (3 studies) Very low
Systolic blood pressure (mmHg, follow-up: 12–24 wk) –5.7 –4.83 0.87 (–2.56 to 4.39) 404 (6 studies) Very low
Diastolic blood pressure (mmHg, follow-up: 12–24 wk) –3.4 –3.56 –0.16 (–2.89 to 2.56) 404 (6 studies) Very low
Triglyceride (mg/dL, follow-up: 12–24 wk) –22.0 –23.51 –1.51 (–17.06 to 14.04) 432 (6 studies) Very low
LDL-C (mg/dL, follow-up: 12–24 wk) –12.48 –12.72 –0.24 (–5.08 to 4.59) 387 (5 studies) Very low
HDL-C (mg/dL, follow-up: 12–24 wk) 0.0 –0.17 –0.17 (–3.27 to 2.89) 432 (6 studies) Very low
HbA1c (%, follow-up: 12–24 wk) –0.31 –0.20 0.11 (–0.04 to 0.26) 173 (3 studies) Very low
Fasting glucose (mg/dL, follow-up: 12–24 wk) –3.00 –3.89 –0.89 (–4.30 to 2.53) 359 (5 studies) Low
Fasting insulin (μU/mL, follow-up: 12–24 wk) –2.6 –3.03 –0.43 (–1.99 to 1.14) 314 (4 studies) Low
HOMA-IR (follow-up: 12–24 wk) –0.94 –1.16 –0.22 (–1.48 to 1.05) 119 (2 studies) Very low

GRADE Working Group grades of evidence: High quality (Further research is very unlikely to change our confidence in the estimate of effect); Moderate quality (Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate); Low quality (Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate); Very low quality (We are very uncertain about the estimate).

*The basis for the assumed risk is the mean change of outcomes compared to baseline in the control group across studies, and the corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group; mLCD for overweight/obesity: Patient or population (patients with overweight/obese), Intervention (mLCD); VLCD for overweight/obese: Patient or population (patients with overweight/obesity), Intervention (VLCD); §Intermittent fasting for overweight/obesity: Patient or population (patients with overweight/obesity), Intervention (intermittent fasting).

CI, confidence interval; GRADE, Grading of Recommendations Assessment, Development and Evaluation; mLCD, moderately-low carbohydrate or low carbohydrate diet; LDL-C, lowdensity lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; HbA1c, glycosylated hemoglobin; VLCD, very-low carbohydrate diet; HOMA-IR, homeostatic model assessment for insulin resistance.