Intermittent fasting for nonalcoholic fatty liver disease Original paper

In this meta-analysis of randomized controlled trials in participants with nonalcoholic fatty liver disease, intermittent fasting improved a variety of clinical outcomes.

The effect of intermittent fasting on clinical endpoints in people with nonalcoholic fatty liver disease (NAFLD).

The outcomes assessed were anthropometrics (body weight, BMI, waist circumference, waist-to-hip ratio), liver enzyme levels (ALT, AST), blood lipids, HOMA-IR, fasting glucose, liver fat, and liver stiffness.

A total of 840 participants (average age of 42; 55% women, 45% men) with NAFLD.

A meta-analysis of 10 randomized controlled trials was performed. The type of IF intervention varied between studies and included the 5:2 diet, alternate-day fasting, time-restricted eating, and Ramadan fasting. The intervention duration ranged from 4 to 52 weeks. Most of the studies took place in Middle Eastern or Asian countries.

Compared to the control group, IF reduced weight (−2.66 kg/−5.86 lb), BMI, triglycerides (−21 mg/dL), insulin resistance, ALT (−6 IU/L), AST (−5 IU/L), liver fat (2 studies, both of which involved the 5:2 diet), and liver stiffness.

Because of the small number of studies included for each subtype of IF, it’s unclear whether some forms of IF are superior to others for certain outcomes. A second limitation is that the control group varied between studies. IF was compared to a “nonfasting” or “standard of care” group in most studies, 1 study compared IF to “caloric restriction”, and 1 study compared it to a group using the weight-loss drug liraglutide. This limitation further increases the uncertainty in whether one form of IF is better than another for a specific outcome.