BOB DOUGHTY: A virus called AD36 could be involved in the gain. Its presence has been connected to obesity in adults. And the team says changes in time spent in light or dark environments influences eating habits.
David Allison says earlier studies found that light differences may
be part of the reason for fatter animals. For example, one kind of animal -- the lemming – experiences body weight changes at different times of the year.
DAVID ALLISON: “We know that light affects weight gain in species like lemmings that gain and lose a great deal of weight in different times of the year, when there is much sunlight versus little sunlight. That is the natural thing for them. So our brains are responsive to light and in ways that relate to body weight.”
BOB DOUGHTY: David Allison says changes in environmental temperature affect weight in both people and animals. The body produces more energy to keep itself warm in the cold. But it produces less energy to cool itself in heat.
DAVID ALLISON: “That all other things being equal, if you put a warm-blooded species like humans or mice or dogs into a colder environment, then they will need to expend more energy to maintain their body temperature. And so, being in a cold environment increases energy expenditure, and if you eat the exact same amount, will lead to lesser body weight. Being in a warmer environment, up to a point, will lead to decreased energy expenditure and therefore, at the same amount of food intake, weight gain.”
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25