动物造模 z-bio 2022-03-01 546

　　Researchers at Loyola University Chicago, co-authors of the groundbreaking study, found that humans have a higher metabolic rate than closely related primates, allowing humans to evolve to be larger brain.

　　The study, published in the journal Nature, found that humans also have a higher percentage of body fat, thus providing energy reserves to speed up metabolism. The findings could point to strategies to combat obesity, the researchers said.

　　Adjusted for body size, the study found, humans had 400 more calories per day than chimpanzees and bonobos (closely related to chimpanzees), 635 more calories than gorillas, and 820 more calories than orangutans.

　　The study's co-authors include Amy Luke, Ph.D., Lara R. Dugas, Ph.D., and Ramon Durazo-Arvizu, Ph.D., in the Department of Public Health Sciences at Loyola University Chicago School of Medicine and Graduate School. The lead author is Dr. Herman Pontzer of Hunter College, New York.

　　The study confirms the researchers' hypothesis that humans evolved a faster metabolism and larger energy budget to accommodate larger brains that burn more calories. A faster metabolism also supports having more offspring and a longer lifespan.

　　For the study, the researchers used an objective technique to measure the total energy expenditure of humans and great apes. Energy expenditure includes the calories expended by the body's metabolism at rest, as well as the calories expended during physical activity. The technique the researchers used to measure total energy consumption is called the double-labeled water method. Total energy expenditure was measured over a period of 7 to 10 days, while apes and humans followed their day-to-day normal life during the measurement. The study included 141 people and 56 zoo animals: 27 chimpanzees, 8 bonobos, 10 gorillas, and 11 orangutans.

　　The study found that the percentage of body fat was significantly higher in humans, and only in humans there was a significant gender difference - 22.9 percent body fat for men and 41.7 percent body fat for women.

　　The human data came from an independent study, led by Luke, called Modeled Epidemiological Transition Studies (METs). Luke and his colleagues are seeking to understand the relationship between physical activity and energy expenditure and weight gain in adults. The modeled epidemiological transition study included adults from the United States, South Africa, Ghana, Seychelles, and Jamaica.

　　Humans and great apes together form a large family called ancient apes. Metabolic measurements in ancient apes may point to a way to combat obesity and metabolic diseases such as diabetes and heart disease.

　　"Humans displayed an evolutionary tendency to store fat, yet other apes remained relatively thin and even maintained moderate activity levels in captivity," the researchers wrote. "Deciphering the diversity of metabolic strategies shaped by evolutionary pressures and physiological mechanisms in extant apes may help to promote and restore metabolic health in both industrialized humans and captive apes."