TABLE 1.
Description of clinical trial studies
| Author (Country) | Study design | Sample % (completed) | Patients included | Intervention | Clinical outcomes | Weight loss outcomes | Liver disease outcomes | Safety |
|---|---|---|---|---|---|---|---|---|
| Lin 2009 (Taiwan) | Randomized open‐label, parallel trial | 95 (72%) | Obesity, NAFLD | Randomized 12 weeks of 450 or 800 kcal/day | Change in body weight, body composition, waist circumference, lipids, liver ultrasound | Average weight loss of 9.2% and 8.9% in 450 kcal/day and 800 kcal/day, respectively | 16% of participants with NAFLD on ultrasound returned to normal by 12 weeks | 103 adverse events (60 may be treatment related); no serious adverse events |
| Contreras 2018 (Spain) | Randomized open‐label, parallel trial | 84 (98%) | Obesity, LAGB candidates, NAFLD | Randomized to 21 days of 800 kcal/day of meal replacement versus 1200 kcal diet prior to bariatric surgery | Body weight change, body composition, liver volume, surgical complications | Weight loss of 5.8% in VLCD compared to 4.2% in LCD | Liver volume reduced by 15.6% ± 11.2% in VLCD and 12.3% ± 10.6% in LCD (not significant) | More participants in VLCD had dizziness (39.5% vs. 12%) and weakness (37.2% vs. 21%) than LCD |
| Chong 2020 (New Zealand) | Randomized double‐blind placebo‐controlled trial | 56 (93.3%) | NAFLD | 4 weeks of 600 kcal/day, then randomized into three groups (MI, PI, PP) for 12 weeks | Maintaining ≥7% weight loss at 16 weeks, changes in ALT, glycemia, lipids, elastography, gut microbiome | Maintenance of ≥7% weight loss was 55%, 53%, and 35% for the MI, PI, and PP groups, respectively | MI group had a significant reduction in ALT of 19.6 U/L | No adverse events |
| Baldry 2016 (UK) | Randomized open‐label, parallel trial | 54 (90%) | Bariatric surgery candidates, NAFLD | Randomized 2 weeks of 800 kcal/day (food‐based or meal replacement shake) | Liver biopsy histological assessment at end of diet, weight loss, inflammatory markers, and difficulty of surgery | Weight loss of 3.6% in the food group and 3.4% in the meal replacement groups (not significant) | 50% of food group and 64% in the meal replacement group had steatosis (not significant) | 1 adverse event and 1 serious adverse event likely unrelated to intervention |
| Cunha 2020 (Brazil) | Randomized open‐label, parallel trial | 39 (84.8%) | Obesity, NAFLD | Randomized to 2 months of either low carbohydrate (<50 g) 600–800 kcal/day diet or diet with 15% deficit (1400–1800 kcal/day) | Body weight change, abdominal MRI to measure visceral adipose tissue area and liver PDFF, elastography for liver stiffness | Average weight loss of 9.6% ± 2.9% in the VLCKD and 1.9% ± 2.4% in the lower calorie group | Liver PDFF mean reduced 38.5% on VLCKD. Liver steatosis (PDFF>5.4%) decreased from 70% to 30% in the VLCKD group | No adverse events |
Abbreviations: ALT, alanine transaminase; LAGB, laparoscopic adjustable gastric banding; LCD, low calorie diet; NAFLD, nonalcoholic fatty liver disease; MI, metronidazole/inulin, PI, placebo/inulin, PP, placebo/placebo; PDFF, proton density fat fraction; VLCD, very low calorie diet; VLCKD, very low calorie ketogenic diet.