Table 2.
Effects of dietary interventions in randomized controlled and randomized parallel group clinical trials demonstrating increases in intrahepatic fat content by magnetic resonance methods.
| Diet | Design, Ref. Cohort N total (males), % NAFLD BMI (kg/m2) |
Intervention Duration |
Δ body mass vs BL vs CTRL |
Liver TAG | Metabolic effects |
|---|---|---|---|---|---|
| Monounsaturated fat | R/C, [71] 14 (14), 0% 22±1 d |
Canola oil vs VCL Once |
↔ ↔ |
Canola oil: ↑ by 33% from -120 min to 240 min (↔ vs -120 min) VCL: ↑ by 7% from -120 min to 240 min (↔ vs -120 min+ BG) |
↔ WB- IS (HEC) |
| Polyunsaturated fat | R/P, [64] 37 (26), 0% 18–27 |
Habitual diet + high SFA vs high-n-6 PUFA muffins 7 w |
SFA: +1.6 kg PUFA: +1.6 kg ↔ |
SFA: ↑ 58% a PUFA: ↑ 53% a,f MRI |
PUFA: ↑ 0.22 of HOMA-IR SFA: ↑ 0.18 of HOMA-IR (↔BG) NR vs BL |
| R/P, [65] 61 (21) , NR PUFA: 30.3 ± 3.7 SFA: 31.3 ± 3.9 |
n-6 PUFA enriched (15% TE) SFA enriched (15% TE) 10 w |
↔ ↔ |
n-6 PUFA: ↓ 0.9% b SFA: ↑ 0.3% b,f MRI/1H-MRS |
Both: ↔ SAT + VAT mass (MRI) BG + vs BL |
|
| Saturated fat | R/P, [80] 38 (17), NR 31 ± 1 |
SFA (60% TE) UFA (59% TE) CARB (24% TE) 3 w |
All: +1.4% e ↔ BG |
SFA: ↑ 55%e,f UFA: ↑ 15%e CARB: ↑ 33%e 1H-MRS |
SFA: ↓ IS e (HEC) |
| High fat/high protein diets | R/C, [70] 10 (10), NR 22.4 ± 0.6 |
Hypercal+HF (+100% fat intake) Hypercal+HFHP (+100% fat +>100% protein intake) Isocal 4 d |
HF: ↔ HFHP: +1.1 kg e ↔ BG |
HF: ↑ 90% e HFHP: ↑ 68% a,e,f 1H-MRS |
↔ in the fEGP ↔EGP (2-step HEC) |
| High fat diet | R/P, [78] 20 (20), NR LF: 29.3 ± 0.6 HF: 28.3 ± 0.5 |
LF (20%TE) HF (55% TE) → LF to HF after 3 w 6 w |
NR | LF: ↓ 13% HF: ↑ 17% f NR vs BL 1H-MRS |
↔ IMCLC BG (histology) ↔ IS BG (HEC) NR vs BL |
| R/C, [79] 10 (0), NR 33 ± 4 |
LF (16% TE) HF (56% TE) 2 w |
↔ ↔ |
LF: ↓ 20% ± 9% e HF: ↑ 35% ± 21% e,f 1H-MRS |
↔ VAT + SAT mass (MRI) BG + vs BL |
|
| Energy-dense diet | R/P, [66] 36 (36), 0% 19.5–24.5 |
Habitual diet + 3 L/HF HS Habitual diet + HS beverage, consumed 3x/d with meals or 2–3 h after meal 6 w |
All: +2.5 kg c,e ↔ BG |
↔ in groups consuming beverages with meals, HF HS: ↑ 45%e HS: ↑ 110%e when consumed between meals (↔ in between meals groups) 1H-MRS |
↔ in WB-IS (2-step HEC) BG+ vs BL |
| Fructose | R/P, [67] 32 (32), NR Fru 30 ± 1.4 d Glu 28.9 ± 1.7 d |
StdD + Glu (25% TE) StdD + Fru (25% TE) 2 w |
Fru: +1.0 kg e Glu: +0.6 kg e ↔ BG |
Fru: ↑ 24% a,e Glu: ↑ 26% a,e (↔ BG) 1H-MRS |
Fru: ↑ 0.8 f HOMA-IR Glu: ↑ 0.1f HOMA-IR |
| R/C, [73] 10 (10), NR 19–25 |
StdD+Fru (3.5 g/kg/FFM) StdD+Glu (3.5 g/kg/FFM) 7 d |
Fru: +0.6 kga,e Glu: +1 kga,e |
Fru: ↑ 52% ± 13% e Glu: ↑ 58% ± 23% a ↔ BG 1H-MRS |
↔ FG + Ins Glu: ↑IMCLC (1H-MRS) e,f Fru: ↔IMCLC |
|
| R/C, [74] 9 (9), NR 22.6 ± 0.5 |
StdD + high Fru (3 g/kg)+PLC (6.6 g/day maltodextrin) StdD + high Fru (3 g/kg) + AAs (20.3 g/day) 6 d |
↔ ↔ |
High-Fru + PLC: ↑ 115% a,e High-Fru+ AAs: ↑ 81% a,e,f 1H-MRS |
↔ for glycemia 9 h after oral fructose loading | |
| Beverages | R/P, [68] 47 (17) , 0% 26–40 |
StdD + 1 L/d of cola, semi-skimmed milk, diet cola, or water 24 w |
NR ↔ BG |
Cola: ↑ 132%–143% vs other groups e ↔ milk, diet cola or water 1H-MRS |
Cola: ↑ 24%–31% VAT (dxa) vs other groupse (Significant difference between regular cola + milk) Cola: ↑ IMCLC (MRS) vs other groupse |
Single group assignment studies and non-randomized parallel group studies were excluded.
Subject data presented as mean (±SEM) unless otherwise stated.
AAs: amino acids, ALA: alpha-linolenic acid, BW: body weight, BG: between groups, BL: baseline, BMI: body mass index, CARB: simple sugars, CTRL: control, d: day, DHA: docosahexaenoic acid, dxa: dual-energy X-ray absorptiometry, EA: eicosapentaenoic acid, EGP: endogenous glucose production, fEGP: fasting endogenous glucose production, FFM: free fat mass, FG: fasting glucose, Fru: fructose, g: grams, Glu: glucose, HbA1c: glycated hemoglobin, HEC: hyperinsulinemic euglycemic clamp, HF: high fat, HFHP: high fat high protein, HOMA-IR: homeostasis model assessment of insulin resistance, 1H-MRS: proton magnetic resonance spectroscopy, HS: high sugar, Hypercal: hypercaloric, IMCLC: intramyocellular lipid content, Ins: insulin, IS: insulin sensitivity, isocal: isocaloric, kg: kilograms, LF: low fat, min: minutes, MRI: magnetic resonance imaging, MD: Mediterranean diet, N: number, NA: not assessed, NAFLD: non-alcoholic fatty liver disease, NASH: non-alcoholic steatohepatitis, NEFA: non esterified fatty acids, NR: not reported, PLC: placebo, PUFAs: polyunsaturated fatty acids, Ref: references, R/C: randomized controlled, R/P: randomized parallel group, SAT: subcutaneous adipose tissue, SG: single group assignment study, SFA: saturated fatty acids, StdD: standard diet, TAG: triacylglycerol, T2DM: type 2 diabetes mellitus, TE: total energy, TG: triglycerides, VAT: visceral adipose tissue, UFA: unsaturated fatty acids, VCL: vehicle, vs: versus, w: weeks, WB: whole body.
Estimated from table/graph.
Median.
Pooled data.
mean ± SD.
Significant effect of intervention (p < 0.05) according to the manuscript.
Significant difference between groups (p < 0.05) according to the manuscript.