Insects put on an Atkins Diet could hold clues to human obesity.
"We basically took two sets of 200 caterpillars and put them into two different nutritional environments with 100 blocks of artificial food," said Spencer Behmer, an assistant professor in the Department of Entomology.
The diamondback moth caterpillars were monitored for adaptations to their surroundings.
"The two environments were like two grocery stores, with one having high protein, low carbohydrate items like meat, and the other having high carbohydrate, low protein items like doughnuts and pretzels," he said.
The caterpillars were forced to shop in these "grocery stores" for eight generations.
"While one set of caterpillars lived on a South Beach or Atkins diet, the other 200 binged on a high calorie carbohydrate diet, like living on potato chips and Coca-Cola," Behmer said.
Behmer and his team had their work published in the Proceedings of the National Academy of Science.
The results were surprising because Behmer and his team were expecting the caterpillars on the high protein diet to turn out to be lean by the time they reached the eighth generation. Instead, these caterpillars became more efficient at using the carbohydrates and creating fat reserves. The other set of caterpillars changed their metabolism in such a way that they converted less of the ingested carbohydrate into fat.
Behmer said that while insects might not physiologically resemble humans, they do require proteins, carbohydrates and minerals like humans do.
"Therefore, we share the same nutritional requirements," he said.
This study can help scientists dealing with human obesity. Behmer said eight generations of caterpillars is the equivalent of 160 years for humans.
"Western diets have traditionally been more carbohydrate influenced, hence the effect of such diets on other cultures like the Hispanic Americans," Behmer said. "The diets can and have led to large numbers of obesity cases (in Hispanic-Americans), and it will be awhile before their bodies can synthesize these high calorie diets."
Americans consume high quantities of sugar and starch and this leads to an obesity epidemic, Behmer said.
"Obesity is not just a diet thing, it also affects an individual's activity. For example, an obese person would rather drive than walk," Behmer said.
A study conducted by the American Obesity Association reported that obesity in the United States occurs at higher rates in racial and ethnic minority populations such as Hispanic-Americans. These nutritional environments have caused obesity and diabetes cases to rise by 30 to 40 percent in Hispanic-Americans in 1999 to 2000.
Jairam Vanamal, a research scientist from the Center of Obesity Research and Program Evaluation agrees with the study conducted at A&M.
"This is interesting work and has been published in a reputable journal, but it needs further work before we can extrapolate it to humans, because we lead a very complex lifestyle and there are a variety of factors that influence human obesity," Vanamal said.
Freder Medina, a graduate student from the Department of Entomology, said insects adapt more quickly because they go through multiple generations in a short time, while humans adapt much more slowly.
