Insulin, Obesity, and Exercise

We learn a biochemical aspect of something we already knew in “Movement Comes With Appetite” (ScienceDaily, December 21, 2009):

A body that is provided with food too often gets caught up in the maelstrom of a lack of exercise, obesity and ultimately diabetes. The trigger is a molecular switch that is controlled by insulin, a new study by scientists from ETH Zurich has revealed. … If a person or animal ingests food, the beta cells in the pancreas release insulin, which blocks Foxa2. When fasting, there is a lack of insulin and Foxa2 is active. In the brain, the scientists have discovered, Foxa2 assists the formation of two proteins: MCH and orexin. These two brain messenger substances trigger different behavior patterns: the intake of food and spontaneous movement. If mammals are hungry, they are more alert and physically active. In short, they hunt and look for food. “If you watch a cat or a dog before feeding it, you can see this very clearly,” says Stoffel. Copyright © 1995-2009 ScienceDaily LLC  —  All rights reserved

Interesting.