November 25, 2010
Study: Alternative Causes Of Weight Gain
(Ivanhoe Newswire) -- Fighting obesity may not be as clear cut as eating right and exercising. A recent study conducted at the University of Alabama at Birmingham demonstrates that there is much more to the obesity epidemic than meets the eye.
Led by biostatistics professor David B. Allison, Ph.D., the study began with the analysis of previous data about little primates called marmosets, which was collected at the Wisconsin Non-Human Primate Center. The population had gradually demonstrated significant weight gain, but no obvious reason could be found to explain it. In particular, controlled diet change appeared to have little effect on the strange occurrence.
Allison set out to find more data, looking at studies of mammals living around humans for at least ten years. He separated his findings into 24 data sets on 12 groups of 20,000 animals. Some of the groups were lab primates and rodents, some were domestic animals and others were strays, but one constant was observed among them all: a gradual, overall weight gain in their respective populations. Out of the 24 sets, 23 had an increase in the amount of obese members within the groups.
"And yet there was no single through running through all 24 data sets that would explain a gain in weight," Allison was quoted as saying. "The animals in some of the data sets might have had access to richer food, but that was not the case in all data sets. Some of the animals might have become less active, but others would have remained at normal activity levels. Yet, they all showed overall weight gain. The consistency of these findings among animals living in different environments, including some where diet is highly controlled and has been constant for decades, suggests the intriguing possibility that increasing body weight may involve some unidentified or poorly understood factors."
Although the common culprits of increased food intake and low activity level are certainly valid, scientists are starting to look at a few alternatives. The first is light exposure. According to various studies, eating habits are influenced by the amount of light one absorbs each day, so even small changes in exposure can make an impact. Allison questions if the light pollution brought on by industrial age has been a factor in obesity.
A second alternative cause of obesity is viruses such as adenovirus-36, which has been linked to obesity due to the amount of AD36-fighting antibodies typically present in obese individuals.
Epigenetics are another possible cause. These are the genetic modifications resulting from environmental factors such as stress, availability of resources, predation and climate change. Any number of adaptive modifications could influence weight gain.
Understanding these alternative causes, and finding the many solutions needed to fight them, will require greater exploration and research.
SOURCE: University of Alabama at Birmingham, November 2010