Should be well below room temp here
David Mendosa found a 2016 research report suggesting that cool temperatures may help with weight management by activating our brown fat, which burns more calories. Heat generated by brown fat is derived from glucose and triglycerides. Keep in mind as you read further that a comfortable environment temperature for a clothed human is about 23°C or 73°F. Those temps don’t stress our bodies by requiring us to either generate or dissipate extra body heat.
Researchers have discovered that when we get mildly cold, which they define as being cool without shivering, our bodies burn more calories. As a result, managing our weight can be easier.
This is the conclusion of a recent review that two researchers at Maastricht University Medical Center in the Netherlands published in the November 2016 issue of the professional journal Diabetologia. The title of their article, “Combatting type 2 diabetes by turning up the heat,” puzzled me at first.
The title confused me because the study is about turning down the heat in the room we’re in. But then our bodies compensate by turning up their internal heat production.
When our body does this, its energy expenditure increases, ratcheting up our metabolism. Being mildly cold revs up our bodies’ brown fat, which unlike white fat, burns calories instead of storing them.
It’s not quite clear how much cold exposure it takes to turn on your brown fat. From the link above:
Cold acclimation by intermittent exposure to a cool (14–17°C) [57–63°F], or cold (10°C) [50°F] environment resulted in significant increases in NST [non-shivering thermogenesis or heat production] capacity. A 10 day cold acclimation study with 6 hour exposure to 14–15°C [57–59°F] per day was enough to significantly increase NST by 65% on average. A 6 week mild cold acclimation study (daily 2 hour cold exposure at 17°C [63°F]) also resulted in an increase in NST together with a concomitant decrease in body fat mass. The latter two studies also revealed significant increases in BAT [brown adipose tissue] presence and activation. All in all, cold-induced BAT activity is significant in adults and parallels NST. The actual quantitative contributions of BAT and of other tissues (e.g. skeletal muscle) to whole-body NST are, however, not elucidated and await further studies. Furthermore, more information is needed on the duration, timing and temperatures to find out which treatments are most effective with respect to increasing NST.
Furthermore, cold exposure over the course of 10 days increased insulin sensitivity in T2 diabetics by 43%. Eight study subjects, probably in the Netherlands, were exposed to temps of 14–15°C [57–59°F] but I don’t know for how many hours a day. Increased insulin sensitivity should help keep a lid on blood sugar levels and reduce the need for diabetes drugs.
In case you’re elderly, obese, or have type 2 diabetes, be aware that the activation of brown fat by cold exposure is not as robust as in others.
On the other hand, I found evidence that higher ambient temperatures (above 23°C) [73°F] may also help with weight management, regardless of what brown fat is doing. Science is hard.
Steve Parker, M.D.
PS: Check out my books for more ideas on weight management.