Because it has nothing to do with sleepless nights, sick kids, and lack of time and money.
"The study authors conclude that pediatricians should talk with new parents about eating better and not neglecting exercise after kids come along."
If pediatricians start telling new parents to eat well and exercise, more pediatricians will be beaten by new parents at well-baby visits :-)
I remember having a newborn and not even being able to spoon the food into my mouth because I couldn't let go of him while he was latched on eating. My husband had to spoon-feed me. Never mind cooking something healthy and exercising.
Okay, so just to review, the things that make you fat are:
1) Having kids (the above study)
2) Having fat friends (also a study done within the last year)
So all I have to do is be childless, have only conventionally attractive friends and be independently wealthy enough to not work. Well shit, sign me up!
So, my anecdotal evidence to counter this is that I totally did start eating better once pregnant and having had the kid. It was one thing to feed myself crap, I do a double-take before feeding it to the kid. Not saying it doesn't have plenty of "bad" food, just that it is more of a conscious decision for a treat. Before I had him every meal was crap and a "treat" for me.
We are pretty much huge health food eaters around here, but I defy anyone who says that it isn't work. It is a shitload of work. And exercise? Ha. I'm a stay at home, so I theoretically have "time." (But I sometimes dream of back to work and trying to workout during lunch.) And once he was 2, I joined a gym but between days that I'm sick, he's sick, we are infrequent attenders. But the gym with good childcare is expensive. And even good "childcare" isn't always a good fit for all kids--I have a very social kid happy to make new friends every time he arrives at the gym. And many other suggestions were always laughable to me. Baby yoga? My kid wouldn't sit still from the moment he was born. Oh, and can I mention the taxing the baby and pregnancy did to me? Spare time goes to physical therapy.
Maybe I'm misreading. Totally possible, given the sleep deprivation. But it sounds like men didn't notice an increase in BMI after having children? Maybe that's because women gain large amounts of weight and change their body composition totally while being pregnant? That we biologically have to gain weight and increase fat stores to provide energy after birth for nursing? You mean it might just be one of those things and not because we're horrible lazy slobs? Huh. Go figure!
I'm wondering how they define exercise. I've never been much on "working out" in a gym or hopping around in front of some guy telling me what to do on TV, but I move a lot more than I used to. I'm constantly picking up a 25 lb. toddler or chasing him up and down the playground equipment or going on walks with him. I tote around a heavy diaper bag and carry laundry. When he was littler, I wore him in a sling or mei tai. I guess it's only exercise if I'm walking with weights in my hands instead of a kid?
On the bright side, I do eat healthier now than I did pre-kid. That has an awful lot to do with his allergies not leaving room for any processed or convenience food and with me being one of the lucky ones who has a spouse earning enough for me to be able to stay home. I spend hours a day in the kitchen. I'm healthier now than I ever have been in my life, but I pay for it in time spent prepping and cooking meals.
Not sure what I'd say if my kid's doc tried to tell me this. Considering that none of the group's many doctors we saw over the first year were willing to listen to me and figure out why he was so freaking sick all the time, I'd probably have used my angry voice on them. Don't want to figure out what's wrong with my suffering child, but are willing to tell me I'm letting myself go and need to sleep a few hours less per night to make time for cooking and exercise? Screw you, Dr. Evil.