Rising winter indoor temperatures in US, UK and other developed countries may be contributing to increase in obesity in those populations, according to a research.
The review paper examines evidence of a potential causal link between reduced exposure to seasonal cold and increases in obesity in the UK and US.
Reduced exposure to cold may have two effects on the ability to maintain a healthy weight: minimising the need for energy expenditure to stay warm and reducing the body's capacity to produce heat.
The review also examines the biological plausibility of the idea that exposure to seasonal cold could help to regulate energy balance and body weight on a population level.
The paper brings together existing evidence showing that winter indoor temperatures have increased over the last few decades and that there has also been an increase in homogenisation of temperatures in domestic settings. Increasing expectations of thermal comfort mean that seasonal cold exposure is decreasing and we are spending more time exposed to milder temperatures.
Lead author Dr Fiona Johnson, UCL Epidemiology and Public Health, said: "Increased time spent indoors, widespread access to central heating and air conditioning, and increased expectations of thermal comfort all contribute to restricting the range of temperatures we experience in daily life and reduce the time our bodies spend under mild thermal stress - meaning we're burning less energy. This could have an impact on energy balance and ultimately have an impact on body weight and obesity.
"Research into the environmental drivers behind obesity, rather then the genetic ones, has tended to focus on diet and exercise - which are undoubtedly the major contributors. However, it is possible that other environmental factors, such as winter indoor temperatures, may also have a contributing role. This research therefore raises the possibility for new public health strategies to address the obesity epidemic."
The study has been published in the journal Obesity Reviews.