Table 2.
Summary of trials evaluating KD effects vs comparative diet in obese subjects.
| Reference | Sample description | Duration | Intervention | Ketone test (concentration in KD group) | Beneficial effects of the KD vs control diet | Side effects of the KD |
|---|---|---|---|---|---|---|
| Sánchez E 2021 (72) | n=30 patients with moderate obesity | 6 months | VLCKD vs hypocaloric Mediterranean Diet | Not tested | ↓BMI ↓total body fat ↓soluble ICAM-1 |
- Gastrointestinal disorders (n=3) - non-fatal episode of heart failure (n=1) |
| Falkenhain K 2021 (73) | n=155 overweight/obese subjects | 12 weeks | Mediterranean ketogenic diet vs calorie-restricted, low-fat diet | Breath acetone | ↓Weight loss ↓HbA1c |
No adverse events reported |
| Michalczyk MM 2020 (48) | n=100 hyperinsulinemic overweight/obese females | 12 weeks | LCKD vs isocaloric control diet | β-OHB= 3.46±0.06 mM | ↓ Glucose ↓ Insulin ↓ HbA1c ↓ HOMA-IR ↓ TG ↑ HDL-C ↓BMI ↓ waist circ. ↓hip circ. |
No adverse events reported |
| Perissiou M 2020 (74) | n=64 obese subjects | 8 weeks | LC vs standard dietary advice (both + exercise program) | Ketosis defined as β-OHB >0.3mM | ↓ body fat ↓ visceral adipose tissue ↓ fat mass ↓ muscle mass ↔ lipids ↓C-reactive protein |
↓lean muscle mass |
| Sun S 2019 (75) | n=58 overweight females | 4 weeks | LC vs control diet | Urinary keto-stick | ↓ BMI ↓waist circ. ↔ fasting glucose ↔ lipids |
↑ fatigue ↑ constipation ↑ diarrhea ↑ headache |
| Hall KD 2016 (49) | n=17 overweight/obese males | 4 weeks of control diet followed by 4 weeks of intervention diet | LCKD vs isocaloric control diet | Plasma acetoacetate= 0.78±0.07 mM β-OHB=0.76±0.07 mM | ↓ energy expenditure ↓insulin ↓C-peptide ↑ FFA ↓TG ↓ leptin |
No adverse events reported |
| Merra G 2016 (76) | n=25 overweight/obese subjects | 3 weeks | VLCKD vs VLCD | Urinary keto-stick | ↓ body weight ↓waist circ. ↔ lean bodymass |
No adverse events reported |
| Lobley GE 2014 (33) | n=12 obese males | 4 weeks per treatment | Cross-overLC vs MCD | Plasma acetoacetate= 0.40 mMβ-OHB= 0.66 mM | ↓ hunger score ↔ brain glucose uptake |
No adverse events reported |
| Johnstone AM 2008 (34) | n=17 obese males | 4 weeks per treatment | Cross-overhigh-protein, LCKD vs high-protein, MCD | Plasma β-OHB= 1.52 mM | ↓ hunger ↓ Ad libitum energy intake ↑ weight loss |
No adverse events reported |
| White AM 2007 (47) | n=19 overweight/obese subjects | 2 weeks | LCKD vs non-ketogenic LC | Plasma β-OHB= 0.72±0.18 mM | ↔weight loss ↔fat mass Positive correlation between ketones and perceived exertion |
↑ fatigue ↑ total mood disturbance |
| Choi HR 2018 (32) | n=46 obese subjects | 2 weeks | ketogenic nutrition drink vs isocaloric balanced nutrition drink | Urinaryketo-stick | ↔ weight loss ↔ fat mass ↑ HDL chol. |
↑ nausea ↑ constipation |
| Yancy WS Jr 2004 (77) | n=120 overweight, hyperlipidemic subjects | 24 weeks | LCKDvslow fat diet | Urinary Ketones (semi-quantitative) | ↑ weight loss ↓ TG ↔LDL chol. ↑HDL chol. |
↑ headache ↑ halitosis ↑ constipation ↑ muscle cramps ↑ diarrhea ↑ weakness ↑ rash |
| Vazquez JA 1994 (78) | n=16 severely obese females | 28 days | ketogenic vs non-ketogenic VLCD | Plasma β-OHB= 3.1±0.5 mM | ↓ plasma glucose ↑ protein oxidation ↔ lipolysis |
No adverse events reported |
| Albanese A 2019 (79) | n=178 obese subjects (candidate to bariatric surgery) | 3 weeks | VLCKD vs VLCD | Not tested | ↑ weight loss ↓ post-operative hospital stay |
No adverse events reported |
| Schiavo L 2021 (80) | n=48 obese subjects undergoing gastric balloon procedure | 4 months | Low-calorie ketogenic diet vs low-calorie diet | Ketonemia=0.18±0.2 mM | ↓ decrease in fat-free mass and resting metabolic rate ↑ fat mass decrease |
No adverse events reported |
LCKD, low carbohydrate ketogenic diet; VLCKD, very low carbohydrate ketogenic diet; VLCD, very low calorie diet; KD, ketogenic diet; MCD, moderate carbohydrate diet; LC, low carbohydrates; BMI, body mass index; β-OHB, 3-hydroxy butyrate; TG, triglycerides.
↓, decrease; ↑, increase; ↔ no changes.