Objective: To grade the evidence from published meta-analyses of RCTs that assessed the associations of IF (zero-calorie alternate-day fasting, modified alternate-day fasting, the 5:2 diet, and time-restricted eating) with obesity-related health outcomes.
Evidence Review: PubMed, Embase, and Cochrane database of systematic reviews were searched from database inception to January 12, 2021. Data analysis was conducted from April 2021 through July 2021. Meta-analyses of RCTs investigating effects of IF in adults were included. The effect sizes of IF were recalculated using a random-effects model. We assessed the quality of evidence per association by applying the GRADE criteria (Grading of Recommendations, Assessment, Development, and Evaluations) as high, moderate, low, and very low.
Findings: A total of 11 meta-analyses comprising 130 RCTs (median [IQR] sample size, 38 [24-69] participants; median [IQR] follow-up period, 3 [2-5] months) were included describing 104 unique associations of different types of IF with obesity-related health outcomes (median [IQR] studies per association, 4 [3-5]). There were 28 statistically significant associations (27%) that demonstrated the beneficial outcomes for body mass index, body weight, fat mass, low-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting plasma glucose, fasting insulin, homeostatic model assessment of insulin resistance, and blood pressure. IF was found to be associated with reduced fat-free mass. One significant association (1%) supported by high-quality evidence was modified alternate-day fasting for 1 to 2 months, which was associated with moderate reduction in body mass index in healthy adults and adults with overweight, obesity, or nonalcoholic fatty liver disease compared with regular diet. Six associations (6%) were supported by moderate quality evidence. The remaining associations found to be significant were supported by very low (75 associations [72%]) to low (22 associations [21%]) quality evidence.
Conclusions and Relevance: In this umbrella review, we found beneficial associations of IF with anthropometric and cardiometabolic outcomes supported by moderate to high quality of evidence, which supports the role of IF, especially modified alternate-day fasting, as a weight loss approach for adults with overweight or obesity. More clinical trials with long-term follow-up are needed to investigate the effects of IF on clinical outcomes such as cardiovascular events and mortality.
METHODS: In this investigator-initiated, single-arm, open-label, pilot study, nine biopsy-proven NASH patients with T2DM were given empagliflozin 25 mg daily for 24 weeks. Liver biopsy was repeated at the end of treatment. The histological outcomes were compared with the placebo group of a previous 48-week clinical trial.
RESULTS: There was a significant reduction in body mass index (median change, Δ = -0.7 kg per m2, p = 0.011), waist circumference (Δ = -3 cm, p = 0.033), systolic blood pressure (Δ = -9 mmHg, p = 0.024), diastolic blood pressure (Δ = -6 mmHg, p = 0.033), fasting blood glucose (Δ = -1.7 mmol/L, p = 0.008), total cholesterol (Δ = -0.5 mmol/L, p = 0.011), gamma glutamyl transpeptidase (Δ = -19 U/L, p = 0.013), volumetric liver fat fraction (Δ = -7.8%, p = 0.017), steatosis (Δ = -1, p = 0.014), ballooning (Δ = -1, p = 0.034), and fibrosis (Δ = 0, p = 0.046). All histological components either remained unchanged or improved, except in one patient who had worsening ballooning. Empagliflozin resulted in significantly greater improvements in steatosis (67% vs. 26%, p = 0.025), ballooning (78% vs. 34%, p = 0.024), and fibrosis (44% vs. 6%, p = 0.008) compared with historical placebo.
CONCLUSION: This pilot study provides primary histological evidence that empagliflozin may be useful for the treatment of NASH. This preliminary finding should prompt larger clinical trials to assess the effectiveness of empagliflozin and other SGLT2 inhibitors for the treatment of NASH in T2DM patients. Trial registry number ClincialTrials.gov number, NCT02964715.