The epigenetic and metabolic basis of obesity memory.

Certain immune and metabolic phenotypes persist in the host long after the original trigger has faded. These phenotypes are maintained by persistent epigenetic and metabolic changes and are increasingly recognised as key determinants of human disease. Obesity, a growing epidemic that affects one in eight people worldwide, provides an ideal terrain to test this hypothesis: it can imprint a long-term memory in adipose tissue and immune cells, making weight loss challenging and sustaining vulnerability to relapse and long-term health risks. We propose that lipid metabolism and signalling may play a central role in establishing and maintaining this memory. We discuss emerging literature defining obesity memory and its molecular basis. Because the field remains in its infancy, we highlight open questions for future studies.