Late-night eating is linked to a 28% higher cirrhosis risk in a 199,155-person cohort

A relative risk needs a baseline, and the baseline here is low. Divide the 315 cirrhosis cases ^[5] by the 199,155 participants ^[1] and the cohort-wide rate comes to about 1.6 per 1,000 over the follow-up ^[16]. If the 28% applied to a baseline near that rate, it would add roughly 0.4 cases per 1,000 ^[20]. That is an illustration only. ScienceAlert's account of the paper does not report how many participants were late-night eaters, how the cases split between them and everyone else, or how many people developed MASLD.

The thing this doesn't tell you is what people ate. The analysis logged when participants snacked, not the snack ^[8]. A difference tied to a time of day could reflect what was eaten at those hours, and these data cannot say. The researchers suggest future work look at what late-night eating consisted of and measure blood sugar and liver fat more directly ^[15].

MASLD is fatty liver disease. Metabolic problems such as obesity lead to fat building up in the liver, and in some people the resulting scarring leads to cirrhosis, where the liver is permanently damaged ^[10]. BMI is therefore the variable to adjust for first, and it was among the adjustments ^[6]. The link between the two diseases also means the 28% and the 36% may not be independent results.

The proposed explanation is circadian. The researchers think the body's built-in day and night cycles may explain the link ^[17]. The liver keeps its own time and connects to the main rhythms, and it may be poorly prepared to handle food late in the evening, with more fat building up and blood sugar rising, though these ideas need further testing ^[18]. In their paper the researchers wrote: "This relationship is biologically plausible; higher evening caloric intake may lead to obesity and metabolic derangement via decreased insulin sensitivity and lower energy utilization at night." ^[19] If obesity is a step on that path, adjusting for BMI would remove some of the effect the study is trying to measure.

Robert Wilechansky, a hepatologist at OHSU, said: "A few studies have hinted at this idea, but this is among the first long-term analyses to explicitly draw the connection to fatty liver disease." ^[11] In our view the result justifies a trial. Wilechansky's team is already recruiting for one ^[9].

He described what the group wants to test: "So we're interested in changing the timing of eating in a way that could make a difference in health, without changing the composition of what people eat." ^[12] The authors add that "The effects of late-evening food intake on liver disease should be further studied in diverse populations, incorporating liver imaging and markers of liver disease severity." ^[13]