Does fasting improve cholesterol?

Recent research suggests that fasting may lower cholesterol. Fasting involves refraining from eating food and sometimes drinking for a certain period of time. People may engage in fasting for a variety of reasons, including possible health benefits or religious reasons.

The liver creates cholesterol for purposes such as contributing to the structure of cell walls, producing vitamin D, and making certain hormones. Types of cholesterol include:

A 2025 study involving 6582 adults who were either healthy or had previous medical conditions tested the effects of fasting on the body. The participants engaged in intermittent fasting, which includes fasting and then eating on a schedule; for example, a person may fast for 16 hours and then have an eight-hour eating window.

The study found that alternate-day fasting, which means fasting on certain days and eating a typical or usual diet on other days, lowered total cholesterol, non-high-density lipoprotein, and triglycerides in participants. However, the same study also found that time-restricted eating resulted in slightly higher cholesterol levels. Time-restricted eating means a person restricts all their eating to a six—to eleven-hour eating window.

A 2024 study also found that intermittent fasting improved total cholesterol, triglyceride, LDL, and HDL levels in 30 participants over a 12-week period.

Other studies also found that intermittent fasting prevents cholesterol from accumulating, halting the progression of cholesterol-related illnesses such as diabetic retinopathy.

A person should always speak with a doctor or healthcare professional before changing or restricting their diet.