In a world that encourages inactivity, even our babies may be moving too little, according to an innovative new study of physical activity patterns during a child’s first year of life. The study, which used tiny activity trackers to monitor babies’ movements, found associations between infants’ squirming, kicking, crawling or stillness and the levels of fat around their middles, raising provocative questions about just how early any links between inactivity and obesity might begin.

We already have considerable evidence, of course, that children in the Western world tend to be sedentary. According to recent estimates, most school-age children in the United States sit for more than eight hours a day, while children as young as 2 or 3 years of age can be sedentary for 90 percent or more of their waking hours. These statistics are concerning, because other studies suggest that inactive children face much higher risks of becoming overweight or obese than children who move more often.

But little has been known about how much — or little — tiny babies move and if there might be correlations between their activities and their rotundity, and if such correlations matter.