It is the dreaded thing to do as a child when you have a lot of energy, but a new study shows not getting your "Z's" can lead to childhood obesity.  The study, released by the Massachusetts’s General Hospital for Children (MGHfC) reports that any child who consistently receives less than the recommended hours of sleep during infancy and early childhood will increase their risk of being obese at 7 years old.

"Contrary to some published studies, we did not find a particular 'critical period' for the influence of sleep duration on weight gain. Instead, insufficient sleep at any time in early childhood had adverse effects,” Dr. Elsie Taveras, chief of General Pediatrics at MGHfC and lead author of the paper, said in a press release.

The study analyzed the long-term effects of lack of sleep from birth to age 7. Mothers were interviewed in person about how much their children slept at 6 months, 3 years, and finally, 7 years, and completed questionnaires when their children were 1, 2, 3, 4, 5, and 6. They were asked how much their child slept at night as well as during daytime naps.  After seven years, measurements were taken to record height, weight, body mass, total body fat, abdominal fat, lean body mass, and waist and hip circumferences.

Sleeping less than 12 hours per day from ages 6 months to 2 years, less than 10 hours per day from 3 to 4, and less than 9 hours per day from ages 5 to 7 was considered inadequate. Children were individually scored from 0 to 13 to rate the highest level of sleep deficiency.

Results showed that children with the lowest amount of sleep had higher levels of body fat including abdominal fat, which is considered more dangerous. Income and ethnicity also affected the outcome of the data.  Less sleep was reported in lower income homes and among minorities.

There is still more research to be done to help understand the correlation between sleep and obesity.  In the meantime, Dr. Taveras said there are measures that can be taken to help ensure children get the proper sleep.

“...Right now we can recommend that clinicians teach young patients and their parent’s ways to get a better night's sleep — including setting a consistent bedtime, limiting caffeinated beverages late in the day, and cutting out high-tech distractions in the bedroom. All of these help promote good sleep habits, which also may boost alertness for school or work, improve mood, and enhance the overall quality of life,” she said.