Circadian disruption caused by irregular eating patterns, shift work, or social jet lag is associated with flattened diurnal rhythms in gut microbial metabolites—including short-chain fatty acids, secondary bile acids, and tryptophan derivatives—leading to impaired metabolic flexibility, increased intestinal permeability, and chronic low-grade inflammation, which collectively promote insulin resistance and hepatic lipid accumulation.

When eating times are irregular, the gut bacteria lose their daily rhythm and stop producing key chemicals at the right times. This causes the gut lining to become leaky, letting bacterial toxins into the bloodstream. These toxins trigger constant low-level inflammation and disrupt liver signals that control sugar and fat metabolism. At the same time, the liver's bile acid cycles and immune signals from the gut break down, further confusing the body's ability to manage energy. Together, this leads to fat buildup in the liver and insulin resistance.