Health and Wellness Body What Is Kourtney Kardashian's Breakfast Obsession? By Kelsey Glein Kelsey Glein Twitter Kelsey Glein is a Seattle-based writer and editor who covers all things fashion, beauty, and pop culture. She was previously the Digital Editor of InStyle and is currently a Social Media Manager at a cosmetics company. InStyle's editorial guidelines Published on April 24, 2015 @ 03:47PM Pin Share Tweet Email Photo: John Sciulli/Getty Images As the mother of three young children, Kourtney Kardashian has a lot on her plate. The star was on-hand to celebrate her sister Kendall Jenner’s campaign for the #mycalvins Denim Series at the Chateau Marmont in West Hollywood last night, and she dished on her realistic approach to fitness and health as a new mom. "Right now I'm working out and eating as healthy and as clean as possible because I am nursing," Kourtney tells InStyle. "It's a fine balance between exercising and making sure that I eat enough. I have oatmeal every morning with whole milk, bananas, and cinnamon, and it's just the best thing ever. I also work with my trainer DB Donmatrix, and it's been helpful to book a time and go with a Khloe or another friend to work out. That helps me to commit to working out and stops me from skipping out." Kourtney Kardashian Explains How Baby Reign Aston’s Name Came to Be Kardashian also revealed that adding a little Balmain also helps---especially with the right pose. "The other night I was in Vegas for my birthday, and I wore a Balmain skirt that made my waist look really tiny. But I kept my hands at my sides and you couldn’t even event tell," she shares. "Afterwards I thought, 'Why did I do that?' I'm probably the least harsh on myself, and I try not to scrutinize everything about my body. As a new mom it is what it is, and we just have to do our best." PHOTOS: Kourtney Kardashian’s Best Maternity Style Moments