A study in 2011 linked the gradual rise in thermostat settings in the US and UK to rising obesity levels (but correlation doesn’t prove causation). The study also found people tend to burn more energy at rest while sitting in cool rooms.
A more recent study looked at the themostat settings of 1600 people across 6 years. Those who kept their home thermostats above 20 C were twice as likely to become obese during the study period.
This phenomenon focuses on the effects of “brown fat”, an unusual form of fat that actually burns energy to help keep you warm.
Relative mild bouts of cold exposure for as little as 10 ten days cause brown fat activity to increase. Causing an increased resistance to cold temperatures and an increase in calories burnt.
A similar cold exposure protocol to the 1st study found increased resting energy expenditure and a decrease of 5.2% in body fat mass. A control group exposed to higher temperatures didn’t show any fat loss.
These studies aren’t claiming that bad thermostat settings are causing an obesity crisis. However, it is worth realising that after 10 days of cold exposure subjects reported much higher comfort ratings.
Keeping your house warm can come at a cost, so turning down your thermostat could save you money, do your bit for the environment and be a lot more comfortable than you originally thought.