Table 1. Summary of clinical trials.
BMI: body mass index, BSA: Body surface area, CASPAR: Classification criteria for psoriatic arthritis, CRP: C-reactive protein, DLQI: dermatology life quality index, DMARDS: disease-modifying antirheumatic drugs, ESR: erythrocyte sedimentation rate, Kcal: kilocalorie, LDL: low density lipoprotein, LED: low energy diet, MTX: methotrexate, PASI: psoriasis area and severity index, RCT: randomized clinical trial, SHD: standard hospital diet, TNF: tumor necrosis factor, VAS: visual analogue scale for pain.
| Study | Design | Intervention | Size | Inclusion Criteria | Results |
| Rucevic et al., 2003 [12] | Controlled trial | Dietary intervention: low energy diet (LED): 800 kcal vs. Standard hospital diet (SHD): 2100 kcal | LED: (n=42) SHD: (n=40) | Hospitalized patients. No metabolic or liver disease. Plaque psoriasis for more than 10 years. BSA≥30% | At 4 weeks no weight reduction changes between either group. LED showed significant reduction in LDL which is correlated with improved psoriasis (p<0.05). |
| Gisondi et al., 2008 [13] | RCT (Blind investigator) | Cyclosporine + Low caloric diet (intervention) VS. Cyclosporine only (control) | Intervention: (n=30) Control: (n=31) | Plaque psoriasis. PASI≥10% BMI≥30 BSA≥10% | At week 24, 7% weight reduction in intervention group, 0.2% in control. PASI 75=66.7% in intervention group vs 29% in control (P<0.001). |
| Di Minno et al., 2012 [14] | RCT (Blind investigator) | TNF-Alpha inhibitor + either: Low calorie 1500 kcal diet (intervention) Free diet (control) | Intervention: (n=63) Control: (n=63) | Psoriatic arthritis (CASPAR criteria) Failed DMARDS | At 24 weeks, low calorie diets achieved better weight control and better ESR and VAS reduction compared to controls. |
| Giglio et al., 2012 [15] | RCT (Blinded) | Low calorie diet (1200-1600 kcal) vs. Routine diet. Previous MTX patients. | Intervention: (n=22) Control: (n=20) | Plaque psoriasis BMI≥30 | At weeks 12 and 24, intervention group showed more weight reduction than control. No other changes were noted. |
| Kimball et al., 2012 [16] | RCT (Blind investigator) | Phototherapy 3x/week plus either: Ornish diet South beach diet No specific diet (control) | Ornish: (n=10) South beach: (n=10) Control: (n=10) | Plaque psoriasis BMI≥20 PASI≥10 | Dietary intervention at 12 weeks showed significant weight reduction compared to control. No significant change in mean PASI between groups. |
| Jensen et al., 2013 [17] | RCT | Anti-psoriatic treatment + either: Low calorie diet (800-1000 kcal) Routine diet (control) | Intervention: (n=30) Control: (n=30) | Plaque psoriasis BMI≥27 | At 16 weeks, intervention group lost more weight 15.4 kg and achieved better PASI (p=0.06) and DLQI (p=0.02) compared to control. |
| Roongpisuthipong et al., 2013 [18] | Uncontrolled trial | Low calorie diet with topical steroids | (n=10) | Plaque psoriasis Metabolic syndrome BMI≥30 | At 12 weeks, patients lost 9.6% body weight. PASI 50=50%, DLQI=62.5%. |
| Naldi et al., 2014 [19] | RCT (Blind assessor) | Systemic treatment + either: Dietetic plan - diet and exercise- (intervention) Informative plan - advice about importance of diet-(control) | Intervention (n=151) Control: (n=152) | Plaque psoriasis BMI≥25 No other diagnosis No ongoing weight loss treatment | Change in PASI scores at 20 weeks from baseline showed a change in median PASI of 48% in intervention vs 25.5% in the control group (p=0.02). |
| Al-Mutairi & Nour, 2014 [20] | RCT | TNF-Alpha inhibitors + either: Low calorie diet: ≤1000 kcal (intervention) or Normal diet (control group) | Intervention (n=131) Control (n=131) | Obese patients Stable plaque psoriasis, PASI 20:50 Receiving biologic therapy (anti TNF-a) | At week 24, the intervention group lost 12.1 kg, achieved 84% improvement in PASI scores compared to 1.5 kg and 69%, respectively, for the control group (p<0.001). |
| Gerdes et al., 2016 [21] | Prospective RCT pilot study | Patients with psoriasis receiving online weight loss coaching compared to no intervention | Online coaching (n=8) No coaching (n=9) | Obese patients with psoriasis with stable treatment were enrolled. | No clear change in the severity of psoriasis was noted between groups. |