Gary Taubes’ Good Calories, Bad Calories is overall a very good book, especially in its description of evidence. But there is also this:
Life is dependent on homeostatic systems that exhibit the same relative constancy as body weight, and none of them require a set point.
How does he think body temperature is regulated? Taubes continues:
It is always possible to create a system that exhibits set-point-like behavior or a settling point without actually having a set-point mechanism involved. The classic example is the water level in a lake, which might, to the naive, appear to be regulated from day to day or year to year, but is just the end result of a balance between the flow of water into the lake and the flow out.
No, lakes do not “appear to be regulated” because they do not exhibit anything like hunger or feeling cold. When the water level in a lake is lower than usual, nothing happens to push the level back up. Taubes continues:
When Claude Bernard discussed the stability of the milieu interne and Walter Cannon the notion of homeostasis, it is was this kind of dynamic regulation they had in mind, not a central thermostatlike regulator in the brain that would do the job rather than the body itself.
Michel Cabanac would not enjoy reading this. Whatever Bernard and Cannon had in mind, there is a “central thermostatlike regulator in the brain” that controls body temperature. It makes us seek warmth — take a warm shower, drink hot drinks, put on a jacket — when our body temperature is too low and do the opposite — such as drink cold drinks and eat ice cream — when our body temperature is too high. When our body temperature is too high, we find a warm shower more pleasant than when our body temperature is too low. These changes are obvious — at least, once you look for them — and imply a thermostat in the brain.