It’s Memorial Day Weekend in America and for those of us in the north, this often means spending time outdoors with friends and family, wearing a bathing suit for the first time since the end of the last summer. In the interim, unchartered areas of paunchiness may have aggregated and we hate it!
This is a truly fascinating documentary about our historic relationship with bodily fat and dramatic developments in the science of fat. One may be surprised to know that fat is an organ (!)
1995 was the year of the discovery of leptin, the hormone manufactured by fat that communicates with the brain. The adipocyte (fat cell) quickly went from being seen as the most boring, low-functioning cell in the body into this dynamic member of the neuroendocrine signalling community. Humans are by far the fattest of primates and the scientists interviewed here suggest that human fat stores are commensurate with human brain capacity, due to the enormous amount of energy required by the brain.
Fat is healthy but too much fat, of course, is not and two thirds of the developed world and a growing part of the developing world is either overweight or obese. The way the body responds to obesity is as a low-level infection or an inflammatory disease. The white blood cells attach to fat cells as part of the immune response and are thought to block insulin signalling, resulting in diabetic conditions. Extremely obese individuals, however often do not have diabetes. Diabetes is thought to initiate in those people, who for whatever reason have a limit to the amount of fat they can store in their fat cells before that the fat overflows in the bloodstream, where it lodges in the heart muscle, pancreas, liver and arterial walls, in what’s called “ectopic deposition”, a condition that correlates to insulin resistance.
Humans have only had access to supermarkets, 24-hr convenience stores and drive-through fast food for the past few decades but eons of evolution have not selected for us to choose to lose weight. “There’s no analogy in the natural world for what we’ve done to ourselves. We’re in unchartered territory,” says Harvard evolutionary biologist, Daniel Lieberman.