It’s true that most of us gorge on tons of hors d’oeuvres, decadent roasts, seasonal vegetables and grandiose desserts when the winter holidays roll around, but what effect does giving in so helplessly to the cravings of our taste buds have on our metabolism?
Excessive eating disturbs our bodies’ natural “food clock,” which is an accumulation of interacting genes and molecules that cue our appetites, and tell us when we have had enough to eat. This clock is known technically as the food-entrainable oscillator, and its purpose is to maintain a steady and healthy metabolism. The biological clock is central to behavior and tissue physiology. Our internal clocks function throughout our entire bodies, not just within the brain.
Our food clocks operate in sync with our more general biological clock, which governs functions such as sleeping and walking, rest and activity, fluid balance, body temperature, cardiac output, oxygen intake as well as endocrine glands secretion. The clocks function on a naturally circadian, 24 hour cycle. The food clock is critical in helping our bodies employ our nutritional intake, and controlling genes that assist in digestive absorption.
These food clocks have been found to be under great influence of the environmental stressors and food binges we expose ourselves to or indulge in. Researchers at the University of California, San Francisco, are studying how this clock functions by examining the role of key molecules in our bodies’ metabolism in attempt to annotate what happens when we overindulge at such peculiar times.
“Timing and metabolism evolved together and are almost a conjoined system,” explains Joe Bass, Md.D., assistant professor of medicine and neurobiology and physiology at Northwestern University and head of the division of endocrinology and metabolism at Evanston Northwestern Healthcare.
In one of his studies, Bass and his team recorded the behaviors of test mice with the same genetic backgrounds. All the mice were fed a regular diet for the initial two weeks, and were then separated into two groups: a control that continued on their regular diet, and the group fed a high-fat diet for the remaining six weeks of the study. After two weeks, the mice on the high-fat diet began to exhibit spontaneous shifts from their normal activity, eating and sleeping patterns, whereas the control mice showed no signs of corruption. This study was conducted entirely in the dark, so as to evaluate the sole influence of the internal clock without external factors or cues.
“It’s not just that the animals are eating more at regular meals,” claimed Bass. “What’s happened is that they actually shift their eating habits so that all excess food intake occurs during their normal rest period.”
Similarly, when people binge eat for relatively brief periods of time, they may feel the effects of their choices in the long run. Bass explains that the clock-metabolism cycles feed upon one another, and thus create a vicious loop. Once weight gain (dietary corruption) starts, the clock is also disturbed, amplifying the inceptive problem. This negatively affects the metabolic rate and increases the propensity for obesity and diabetes.