Late-night eating raises liver disease risk by up to 30%

Why this matters: Fatty liver disease, now called metabolic dysfunction-associated steatotic liver disease (MASLD), affects as many as 30% of Americans. It can progress to inflammation, scarring, and cirrhosis, and it is tightly tied to obesity, insulin resistance, and cardiovascular risk. Because liver health is central to metabolic aging, modifiable habits like meal timing deserve attention.

Main findings: Researchers at Oregon Health & Science University pooled data from nearly 200,000 participants in the Nurses' Health Study, the Nurses' Health Study II, and the Health Professionals Follow-up Study. Participants were grouped by when they typically ate, and those groups were compared against reports of fatty liver disease and cirrhosis. People who regularly ate after dinner or around bedtime had a 20% to 30% higher risk of liver disease than people who avoided late eating. The results were published in Clinical Gastroenterology and Hepatology.

Key insights: Earlier work connected late eating to obesity and cardiovascular problems, but few long-term analyses had examined fatty liver explicitly. One proposed explanation involves circadian rhythms. The liver processes nutrients, regulates blood sugar, and manages energy storage on a roughly 24-hour cycle, so eating when the body is biologically primed for rest may disrupt these processes.

Practical implications: Lead author Robert Wilechansky, a hepatologist, suggests that confining calorie intake to the hours before bedtime might be beneficial. A reasonable approach is to finish your last meal several hours before sleep, which is a low-cost change that fits with broader time-restricted eating strategies.

Caveats: This is an observational association, so it cannot prove late eating causes liver disease. Late eaters may differ in diet quality, sleep, shift work, or total calories. The cohorts consisted of health professionals, which may limit generalizability, and eating habits were self-reported. Most people with fatty liver never develop cirrhosis, so the absolute risk increase remains modest. Randomized trials are needed to confirm whether shifting meal timing protects the liver.