UNM Distinguished Professor of Biology Dr. James Brown second author on paper
Ever wonder where all that food your teenager devoured was going? As a matter of fact, not only does the food go into the teen’s daily activities – running, doing homework, breathing and playing video games, but food converted to energy also fuels growth of new tissues – bones, vessels, cartilage, muscle.
In poorer areas of the world part of the energy yielded by food might be necessarily deflected for the body’s defense system in fighting disease. Children and teens in such conditions will not grow as tall or big as their healthy counterparts who were able to allocate a lot more of their energy stores directly to growth.
In the October 31 issue of Science, National Science Foundation funded researchers report on a model that shows that the food baby mammals and birds use to grow always stay proportional to how fast they are growing. The paper, titled "Energy Uptake and Allocation During Ontogeny" says this relationship stays remarkably stable for all sizes and types of animals.
Dr. Chen Hou, Santa Fe Institute and lead investigator, compares the building of an animal to the building of a house
“When you build a house the materials alone are just part of the story. You might pay $1000 for the bricks, but you will spend much more for the workers and the rest of the overhead," said Hou. "Same with building a body – new muscle and bone are just part of the energy expenditure; laying that new tissue down costs much more.”
Previous energy budget models have typically been based on either rates of food consumption or metabolic energy expenditure.
Hou and his colleagues, including University of New Mexico Distinguished Professor of Biology Dr. James Brown, UNM Biology student Wenyun Zuo, who is advised by Brown as well as being second author, and other UNM researchers including Melanie Moses, associate professor, Computer Science and William H. Woodruff, Earth and Planetary Sciences, are the first to reconcile the two approaches and to highlight the fundamental principles that determine rates of food assimilation and the rate of energy allocation to maintenance of a body and to its growth, activity and storage. They confirmed their model with data from 14 different mammals and birds from the chicken to the fox.
In the future they will be interested to see how rate of food intake and rates of growth compare in reptiles and insects.
The current modeling work is not only important in agriculture and husbandry, but will lend key insight into children’s obesity, and the relationship of diet control to exercise and weight loss. This research can also shed light on inquiry into how food restriction can retard aging.
UNM Media Contact: Steve Carr, (505) 277-1821; e-mail: scarr@unm.edu
Posted by scarr at November 6, 2008 11:26 AM