In the days and weeks after giving birth, some new mothers immediately try to slim down on their body weight. They've seen Beyonce do it and Kate Hudson do it, instilling this idea that slimming down after giving birth is an easily achievable and necessary goal.

But the reality of post-pregnancy and losing weight doesn't always meet expectations. A 2014 study found that most women weigh more a year after giving birth, NY Daily News reported.

The study, which followed 774 women who had an average body mass index before giving birth, found that about 75 percent of women weighed more the year after giving birth than they did before getting pregnant, with many women even becoming obese.

"This unfortunately showed that pregnancy itself is leading to obesity or (being) overweight for a substantial number of women," Dr. Loraine Endres, an assistant professor at the University of Chicago, said, NY Daily News reported. "... The more you gain, the harder it is to ever lose that weight. From the moment women conceive, as health care providers we need to start talking with them about appropriate weight gain and remaining active."

But another celebrity says this debate shouldn't matter. Haylie Duff, sister of actress and singer Hillary Duff, recently spoke out against this concept, saying that it's important for new parents to understand that achieving the expectations set out by celebrities or dieting experts doesn't always meet the reality of being a new mother - and that's OK.

"There's this very intense pressure to look like you didn't have a baby two days after you had a baby," Duff told Fox News. "First of all, I didn't get offered that deal with the devil. I didn't get to look like I didn't have a baby two days later, so that just wasn't an option for me. It's great for people who can look like that, but it's so unrealistic for the majority of women in this country, and it also has the tendency to make you feel bad about yourself."

That's why Duff has created a new food blog, called "The Real Girl's Kitchen." Along with eventually becoming a Cooking Channel TV show of the same name, it helps real Americans learn ways to keep a healthy relationship with food.

Managing expectations is something that parents will have to deal with in more ways than just their weight, though. It also comes in to play when considering how they'll be as a parent, or how they'll carry out certain tasks with their children.

Many parents strive to have a perfect baby photo, for example, but that often doesn't meet the reality - mostly because children can sometimes be messy and disrupt what would be a perfect photo.

"Life with kids is rewarding, challenging, and a bit messy. Sometimes a massive cleanup effort or serious bath is required," BabyCenter reported.

To get a better look at the differences between a parent's expectations and the reality, click through our slideshow below.