Feed-fast oscillations, in all organisms, entails differential utilization of fat and carbohydrates as energy source. Liver breaks down fat to produce glucose to sustain energetic needs during fasting, which needs to be stopped upon re-feeding, rapidly. Abnormal glucose production is known to be associated with metabolic diseases. Researchers have discovered that liver microRNAs, synthesized as precursors in anticipation, inhibit the starvation pathways upon re-feeding to control glucose and fat metabolism. An absence of these microRNAs leads to liver dysfunctions and diabetic-like condition.