The food people consume may affect their internal biological clock, according to a recent study.

Researchers found that the internal biological or "circadian" clock can be adjusted through dietary manipulation. The findings may help patients with various conditions and show that insulin may be involved in resetting the clock.

The internal biological clock regulates the daily rhythm of many aspects of human behavior and biology. It plays an important role in preferred sleep times, times of peak alertness, and the timing of certain physiological processes.

"Chronic desynchronization between physiological and environmental rhythms not only decreases physiological performance but also carries a significant risk of diverse disorders such as diabetes, cardiovascular diseases, sleep disorders, and cancer," researcher Dr. Makoto Akashi said in a statement.

The body clock involves two major pathways. The first, which responds to light, has been well characterized. The second, which responds to food, is less understood.

Through experiments in cells and mice, the research team found, using cell culture, that insulin, a pancreatic hormone that is secreted in response to feeding, may be involved in resetting the circadian clock.

"Insulin-mediated phase adjustment of the clock in feeding-relevant tissues may enable the synchronization between mealtime and tissue function, leading to effective digestion and absorption," Akashi said. "In short, insulin may help the stomach clock synchronize with mealtime."

The researchers' findings provide valuable information on how to adjust the circadian clock through dietary manipulation.

"For example, for jet lag, dinner should be enriched with ingredients promoting insulin secretion, which might lead to a phase advance of the circadian clock, whereas breakfast would be the opposite," Akashi said.

Researcher said the findings also suggest that clock adjustments through feeding might not work well in individuals with insulin resistance, a characteristic of patients with type 2 diabetes. Also, there may be side effects related to the circadian clock when treating patients with insulin.

The findings were recently published in the Cell Press journal Cell Reports.