A tremendous amount of ink has been spilled on the near-magical ability of brown fat (BAT) to burn away a person’s waistline. As I’ve been recently reporting, it’s too bad that the science has not quite matched the hype. Otto Muzik at Wayne State University measured BAT’s energy expenditure and calculated it only burns about 20/kcal a day. So if the is a magical property to cold exposure, it’s not brown fat. Still, it’s clear that the body is doing something to keep itself warm in ice water.
The body really only has two options when it comes to heating itself up: It can ramp up energy expenditure, or reduce heat loss through insulation.
When I was writing What Doesn’t Kill Us I came across journals on hydrotherapy from the 1800s that warned, to paraphrase, “cold water could make a thin man thinner and a fat one fatter.” This is because in the cold that thin people can’t rely on an insulating option and therefore must burn more calories to heat up. Meanwhile, someone with a more rotund physique simply won’t lose as much heat and their bodies will not have to work as hard to stay alive.
The general rule of biology and adaptation is that the body will always opt to do less work rather than more work if it has a choice. If it can insulate, it will insulate.
Now, I don’t know of any research that indicates exactly where the tipping point is in the mix between cold exposure and existing body fat that would push the body to choose one strategy over another. My hypothesis is that people who are just starting on their cold exposure journeys almost all start off by burning more calories during exposure because they haven’t started adapting to the new environment. However, over time and consistent practice they send signals to their body to expect more cold in the future and therefore urge it to adapt to the most efficient strategy—making thin people thinner and fat people fatter.
I don’t have any large scale data set to back up this just yet. I’m absolutely open to seeing evidence to the contrary. However, I will note that most polar animals insulate themselves with blubber instead of opting for constant motion. It’s also worth considering photos of well-known ice enthusiasts like Wim Hof and Diana Nyad who are both in their 60s when metabolisms generally slow down. Neither of them are rail thin.
Andrew Huberman Broke his Silence
Ever since the story in New York Magazine on Andrew Huberman’s numerous affairs and scientific chicanery broke on March 25th, people wondered how the famous neuroscientist’s would respond. Other than hiring a white-shoed public relations firm named Scale Strategies to seed stories to conservative media and covertly undermine the author Kerry Howley’s reporting, Huberman was notably silent.
Until last week.
On a three hour podcast with the leadership-influencer and protein powder-slinging Jocko WIllink Andrew Huberman devoted 13 minutes to talking about the story. He claimed that he couldn’t be a sociopath because he loved his dog, that the women he cheated on weren’t “girlfriends” because they hadn’t met his family, and that journalists are simply looking to take down powerful men for clicks and money (because apparently he can’t be influenced by the same forces).
Anyway, I dropped reaction video late last week where I cut out and responded to his response. I know: it’s all very meta.
Join the Honor Roll!
Over the next month I’m making a few changes to the rewards for my supporters on Patreon. Now anyone who signs up for early access to my work (starting at just $5/month) will also see their name appear at he end of my videos in a scrolling honor roll. I’ve been overwhelmed with how many people have come out to support the work that I do and I can’t tell you how much it means to me that you are here. I thought it would be good to recognize you publicly as well.