( Health.com ) -- New parents , particularly mothers , devote so much time and energy to their children that they often fail to adequately look after their own health , a new study in the journal Pediatrics suggests . The study , which followed about 1,500 high school students into their mid-20s , found that those who became parents got far less exercise than their childless peers . For moms , the news gets worse : Unlike fathers , mothers tended to have a higher body mass index ( BMI ) and less healthy diets than women of the same age without kids . The mothers in the study averaged about 400 calories more per day than other women . They also consumed more saturated fat , ate fewer green vegetables like broccoli and spinach , and drank nearly twice the amount of soda , sports drinks , and other sugary beverages . The researchers found no such differences among men . Health.com : 25 ways to cut 500 calories a day . Mothers , who are usually the primary caregivers in a household , may have little time to prepare healthy meals for themselves in addition to what they fix for their children , and so they may be apt to fall back on quick-and-easy processed foods such as macaroni and cheese , says Jerica Berge , Ph.D. , the lead author of the study and an assistant professor of family medicine and community health at the University of Minnesota , in Minneapolis . `` Moms might be having multiple time demands and have to sacrifice making healthier meals , '' she says . `` They cook high-fat , more palatable foods because they do n't have time to do otherwise . '' That 's not to say they 're dining only on junk food , Berge adds . Mothers ate just as much fruit , whole grains , calcium , and fiber as their childless counterparts . `` We found that they are trying [ to eat healthy ] , '' Berge says , `` but they are not able to do it all the time . '' Health.com : Easy meals for families . The study participants were an ethnically and socioeconomically diverse group who were 25 years old , on average . ( To further limit the influence of economic and cultural factors , the researchers controlled for income and race . ) Roughly 10 percent were parents , most with just one child who was a year old or younger . `` It 's a wide enough population to represent what is really happening , '' says Fran Biagioli , M.D. , a family physician at Oregon Health and Science University , in Portland . When it comes to exercise , raising kids appears to cut into workout time for both parents . Each week , moms and dads lost about 60 and 90 minutes of physical activity , respectively , compared to other young adults . For the mothers , less exercise and less-healthy diets added up to a higher BMI , a ratio of height to weight used to estimate body fat . The average BMI was one point higher among moms than among childless women , whereas fatherhood appeared to have no association with BMI . Health.com : 7 steps to instant calm . Biagioli , who was not involved with the research , says the findings reinforce what she tells the many young parents and parents-to-be whom she sees in her practice . `` I talk to them about cleaning up their act , '' she says . `` It 's a conversation that I have early and often . '' Getting through to them before the baby arrives is especially important , Biagioli says , because after that they 'll need all the stamina that a good diet and lots of exercise can give them . `` When they have a newborn , they are sleep deprived and no message will get through , '' she says . The months after becoming a parent are indeed a `` high-risk time '' for young adults , Berge adds . `` It 's a new phase of life , they 're learning to be parents , and there 's a trade-off between parenting and taking care of themselves that they need to be able to balance . '' Copyright Health Magazine 2011 .
New mothers tend to let their health improve while devoting all of their energy to the new baby . The mothers in the study consumed about 10 calories more per day than other women . For the mothers , less - and less - healthy diets add up to a higher BMI .