A/C and FAT!

There have also been claims, that excessive use of air conditioners can actually cause someone to grow fat. Some researchers maintain that with regulated temperatures our body stops adjusting to the temperature changes and since there is a cessation of effort on the part of our body we burn less calories and hence more fat gets accumulated. Such claims need to be clarified better.

Source

As mentioned it is not based on a complete research, however I could find some sense in it, people become lazy, sleepy when it is cold, therefore, they tend to sit idle more, conclusion they get fatter!

Either way I am glad that I prefer to be warm and avoid A/C's most of the time!