There is no question that none of us, not just pediatricians, is doing a very good job of dealing with the obesity problem this nation faces. We can agree that a more active lifestyle that includes spells of vigorous activity is important for weight management. We know that in general overweight people sleep less than do those whose basal metabolic rate is normal. And, of course, we know that a diet high in calorie-dense foods is associated with unhealthy weight gain.
Dr. William G. Wilkoff
Not surprisingly, overweight individuals are usually struggling with all three of these challenges. They are less active, get too little sleep, and are ingesting a diet that is too calorie dense. In other words, they would benefit from a total lifestyle reboot. But you know as well as I do a change of that magnitude is much easier said than done. Few families can afford nor would they have the appetite for sending their children to a “fat camp” for 6 months with no guarantee of success.
Instead of throwing up our hands in the face of this monumental task or attacking it at close range, maybe we should aim our efforts at the risk associations that will yield the best results for our efforts. A group of researchers at the University of South Australia has just published a study in Pediatrics in which they provide some data that may help us target our interventions with obese and overweight children. The researchers did not investigate diet, but used accelerometers to determine how much time each child spent sleeping and a variety of activity levels. They then determined what effect changes in the child’s allocation of activity had on their adiposity.
The investigators found on a minute-to-minute basis that an increase in a child’s moderate-to-vigorous physical activity (MVPA) was up to six times more effective at influencing adiposity than was a decrease in sedentary time or an increase in sleep duration. For example, 17 minutes of MVPA had the same beneficial effect as 52 minutes more sleep or 56 minutes less sedentary time. Interestingly and somewhat surprisingly, the researchers found that light activity was positively associated with adiposity.
For those of us in primary care, this study from Australia suggests that our time (and the parents’ time) would be best spent figuring out how to include more MVPA in the child’s day and not focus so much on sleep duration and sedentary intervals.
However, before one can make any recommendation one must first have a clear understanding of how the child and his family spend the day. This process can be done in the office by interviewing the family. I have found that this is not as time consuming as one might think and often yields some valuable additional insight into the family’s dynamics. Sending the family home with an hourly log to be filled in or asking them to use a smartphone to record information will also work.
I must admit that at first I found the results of this study ran counter to my intuition. I have always felt that sleep is the linchpin to the solution of a variety of health style related problems. In my construct, more sleep has always been the first and easy answer and decreasing screen time the second. But, it turns out that increasing MVPA may give us the biggest bang for the buck. Which is fine with me.
The problem facing us is how we can be creative in adding that 20 minutes of vigorous activity. In most communities, we have allowed the school system to drop the ball. We can hope that this study will be confirmed or at least widely publicized. It feels like it is time to guarantee that every child gets a robust gym class every school day.
Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Other than a Littman stethoscope he accepted as a first-year medical student in 1966, Dr. Wilkoff reports having nothing to disclose. Email him at pdnews@mdedge.com.