It's called "dad bod", and it's not hard to figure out exactly what the problem is.
It's hard to keep up with your exercise routine when you're so exhausted you can barely lift your eyelids, let alone weights. And healthy eating naturally takes a back seat to the idea of eating whatever you can, whenever you can.
Take-away menus become trusted friends, and you find yourself on a first-name basis with pizza delivery drivers.
But it doesn't need to be that way. You don't need a full hour to exercise effectively, and you don't need to spend ages in the kitchen to make healthier meals.
The trick is to keep things simple, scoring small wins where you can that will eventually add up to something much bigger
So here's three simple ways to help ward off the dreaded dad bod.
1: DO WHAT YOU CAN, WHEN YOU CAN
Sure, you're about as likely to find a winning lottery ticket as you are the time to go for 10km run, but that just means you need to sneak in a little exercise whenever you can.
Walk to the shops, or the park, or even around the block. Treat pushing a pram as a potential workout, and seek out hills and tackle them at a run. Use that public workout equipment when you're in the park. And ditch the elevator in place of stairs whenever you can.
All those little things add up, and will go along way to helping ward off those extra kilograms.
2: PLAN YOUR MEALS
In the months after a new baby comes home, your meals are usually dictated by eating whatever you can find in the all-too-brief moments that your child is sleeping, but by planning ahead you can make sure those meals are nutritious and healthy, rather than full of fat and empty of goodness.
Dedicate an hour on Saturday or Sunday to whipping up simple, healthy meals that are easily frozen and reheated (think pastas and soups). That way, you'll find yourself reaching for something healthy, rather than a pizza menu, when you finally sit down to eat. Or consider a meal-replacement for a quick, filling and nutritious meal that won't hurt your waistline.
3: JUST DO IT
The first step is always the hardest, but never has that been more true than when it comes to exercise. Despite feeling like you might never want to move again, training - even a little bit - actually gives you more energy, not less.
Same with eating nutritious food, which will have you feeling sharper in no time.
Adam MacDougall is a former professional rugby League player and the creator of The Man Shake and The Man Challenge.