In the study published in the journal Proceedings of the National Academy of Sciences, researchers from Northwestern University (NU) and New York University School of Medicine propose that variation in the energy needs of brain development across kids, in terms of the timing, intensity and duration of energy use, could influence patterns of energy expenditure and weight gain.
This hypothesis was inspired by a 2014 study showing that the brain consumes a lifetime peak of two-thirds of the body's resting energy expenditure, and almost half of total expenditure, when kids are five years old.
The study also showed that the ages when the brain's energy needs increase during early childhood are also ages of declining weight gain. As the energy needed for brain development declines in older children and adolescents, the rate of weight gain increases in parallel.
"This finding helped confirm a long-standing hypothesis in anthropology that human children evolved a much slower rate of childhood growth compared to other mammals and primates in part because their brains required more energy to develop," said co-author Christopher Kuzawa, a professor of anthropology in the Weinberg College of Arts and Sciences and a faculty fellow with the Institute for Policy Research at NU.
"A major aim of our paper is to bring attention to this gap in understanding and to encourage researchers to measure the brain's energy use in future studies of child development, especially those focused on understanding weight gain and obesity risk," Kuzawa said.
"We believe it plausible that increased energy expenditure by the brain could be an unanticipated benefit to early child development programs, which, of course, have many other demonstrated benefits," he added. "That would be a great win-win."