Calorie Restriction Works Well–For Animals

Calorie restriction, which has been shown to extend the lifespan of animals, has some benefits for humans, but the practice works best if you are an animal, particularly a rat. Researchers at Washington University followed 218 people who reduced their caloric intake by 25 percent for two years. What did they find? A Wash U news release reports that unlike lab animals with similarly restricted diets, the humans did not experience body temperature decreases and lower resting metabolic rates–changes thought to be potential contributors to increased lifespan. The people did lose weight, but not the 15.5 percent weight loss that had been expected, based on animal studies. Instead, they lost an average of 10 percent of their body weight in the first year of the study and maintained that weight during the study’s second year. Wait, there’s more: blood pressure decreased 4 percent. Total cholesterol fell 6 percent. Levels of HDL cholesterol—the “good” cholesterol—rose, and C-reactive protein, a marker of inflammation, dropped by 47 percent.