Seasonal changes are good for you

Your air conditioner is making you fat, your thermostat is giving you diabetes, and if you want to stay healthy it is time to feel a bit of changeable weather.

Experiencing a range of temperatures can have such a powerful effect on our health that offices should consider varying the climate with the seasons, scientists say.

Their suggestion comes as they published research showing that exposing diabetic people to moderately low temperatures produces positive changes in their metabolism.

‘‘Nowadays in modern society we are not forced to undertake physical activity and we are not exposed to a variation in temperature,’’ Wouter van Marken Lichtenbelt, from Maastricht University Medical Centre in the Netherlands, said.

‘‘Our body was not evolved in such an environment, and now we see we get bodies that become obese, insulin insensitive and diabetic. That’s partly because of the way we live, it’s not a healthy situation.’’

A more extreme version of this idea is promoted by Wim Hof, the Dutch ‘‘Iceman’’, who has publicised the health benefits of cold exposure with stunts including trying to climb Everest topless.

Professor van Marken Lichtenbelt said the theories were not completely ludicrous even if the Everest climb had failed.

In the cold, blood vessels experience constriction and flow reduces to the extremities. In heat the reverse happens, keeping us healthy, he argues.

‘‘It’s a huge difference, with a variable temperature you are training your cardiovascular system,’’ he said.

Modern life is designed to avoid just this.

‘‘We live more than 90 per cent of our time inside, and are not exposed to temperature variation.’’

The disadvantages of this are clear, he said, when you see what happens to diabetics.

He exposed a group of people with type 2 diabetes to 15 degC for six hours a day for 10 days.

Their insulin sensitivity increased by 40 per cent, he reported in the Building Research and Information journal.

The Times, London