Overeating has become a popular sport in the United States. And I’m not just talking about events like Nathan's Famous hot dog-eating contest in Coney Island, Brooklyn, N.Y., where Joey "Jaws" Chestnut last month won his sixth consecutive title. He downed 68 dogs with buns in 10 minutes.
Some of these eaters are very serious. A 350-pound man picketed an all-you-can eat fish-fry restaurant in Wisconsin this spring after they had the audacity to cut him off after a dozen pieces of fish. This overeating has, of course, had an effect on the population. During the past 20 years, there has been a dramatic increase in obesity in the United States and rates remain high. Today, one in three adults in the United States is obese and nearly one in four children and adolescents is significantly overweight, according to the Centers for Disease Control (CDC). Overeating is adding to obesity-related conditions including heart disease, stroke, type 2 diabetes and certain types of cancer.
And now there is a different problem related to the all-you-can-eat principle, and it’s in the laboratory, not the kitchen. The widespread practice of allowing lab rats and mice to eat as much as they want may be affecting the outcome of experiments in which scientists use them to test new drugs and other substances.
Laboratory mice and rats are understudies for people when research can’t be done on humans. Researchers Gale Carey and Lisa Merrill point out that the millions of lab rodents used in laboratory studies each year are fed differently from other test animals. While other test animals get regular meals, rodents can eat all they want whenever they want it. They take advantage of this choice and it shows: they put on more weight and more body fat than meal-fed rodents. And the two scientists also point to other research which has found that lab rodents with easy access to food often to develop abnormally high blood fat levels, high cholesterol, nerve and heart damage, cancer and other disorders, much as people do.
The scientists reported in the ACS Journal of Chemical Research in Toxicology that after analyzing 54 studies, they concluded that when rats and mice have free access to food, it likely affects the results of tests for harmful and cancer-causing effects of new drugs and other substances. This could explain why such study results have been so inconsistent recently. They suggest that scientists reconsider using the all-you-can eat approach for lab rodents.