Finn: … and I'm Finn…

　　Rob: … and this is 6 Minute English. In today's programme we're talking about slimming - in other words, doing something to lose weight and get thinner. Not a problem for you Finn?

　　Finn: Well, I do have a small tyre of fat that is growing around my middle - so even I don't have a perfect body!

　　Rob: It doesn't show and maybe you are what we call TOFI - that's thin on the outside and fat on the inside. But for people who perceive - or think they may be fat on the outside, there could be some good news.

　　Finn: Yes, this is to do with research about the temperature of your house. We'll explain more soon and we will look at some related vocabulary. But first Rob, have you got a question for me?

　　Rob: Of course. This is about calories - these are the units that measure how much energy you get from food. People who want to lose weight try to eat food with fewer calories in them. But what is the recommended number of calories an average man needs each day to maintain a healthy weight? Is it:

　　a) 2,000 calories

　　b) 2,500 calories

　　c) 3,000 calories

　　Finn: I should know this. I think it's c) 3,000 calories.

　　Rob: We'll find out if you are right later on. Let's talk more now about a possible new way to slim - or lose weight. New research has found that heating your house too much could make you fat!

　　Finn: And turning the central heating down could make you lose the pounds! This is the claim from Dr Wouter van Marken Lichtenbelt, who is a biologist at Maastricht University Medical Centre.

　　Rob: That's right. He got some brave volunteers to spend six hours every day for ten days indoors, in temperatures of just 15 to 16 degrees Celsius whilst just wearing t-shirts and shorts. That's not something I would normally do!

　　Finn: But these guinea pigs - a name for people who are used in experiments - became accustomed to - or used - the cold, and their metabolism worked faster.

　　Rob: Metabolism is an important thing. This is the chemical process in your body that causes you to burn food and turn it in to energy. So in this research, living in cooler conditions made people's body's burn food faster.

　　Finn: So they burnt off the calories and that means they lost weight. It sounds like a simple and easy diet. I like the sound of a diet that doesn't involve too much effort!

　　Rob: It doesn't mean you can just be a couch potato - you still need to do some exercise. But living in a cooler temperature could help to some extent and this is because of 'brown fat'.

　　Finn: Brown fat! Let's find out more about this from Dr Wouter van Marken Lichtenbelt, who's been speaking to the BBC's Health Check programme. What happens to brown fat when it is activated?

　　Dr Wouter van Marken Lichtenbelt, Biologist, Maastricht University Medical Centre:

　　Brown fat cells are not really filled with fat, but with other particles that can increase energy metabolism a lot. So if brown fat gets activated it produces heat so it warms up the body.

　　Rob: So he says brown fat isn't fat! It has particles that help to increase your metabolism. When it is activated - or starts working - it makes heat and that warms up the body.

　　Finn: It's interesting stuff - and brown fat actually increases after living in cold conditions. It's particularly found in animals that hibernate - the ones that sleep during the winter.

　　Rob: A similar experiment took place in Japan which led to people losing weight. But I find if the temperature is colder, I want to eat more to warm me up -particulary unhealthy food or what we call, comfort food.

　　Finn: Well, the Doctor says we mustn't - and he explains that losing weight this way also depends on other lifestyle factors - so other ways we lead our life, such as exercise and what we eat.

　　Rob: But he does feel understanding environmental conditions - where we live and work - could be useful in the future.

　　Finn: He thinks a factor like temperature has been neglected - or not thought important. But he believes it should be thought about when designing heating and cooling systems for homes and offices. Does this mean I am going to be shivering when I'm at work?!

　　Rob: Well you will be producing extra brown fat instead of the other fat! But seriously, the Doctor is just talking about turning the temperature down a few degrees, not turning the room into a freezer. It would certainly help reduce electricity and gas bills! Well it's time now to reveal the answer to the question I set you earlier. I asked you what is the recommended number of calories an average man needs each day to maintain a healthy weight?

　　Finn: I said c) 3,000 calories.

　　Rob: The answer is 2,500 calories per day. And the recommended number calories for an average woman is 2,000 per day. Well, that brings us to the end of today's 6 Minute English. Please join us again soon.

　　Both: Bye.