It isn't big news—it's harder to shed off the pounds once you reach the big 3-0. We list down the culprits behind the challenge and what you can do about each of them.

1. Your metabolism has betrayed you.
It's true. Your metabolism becomes slower as you age. Remember when you gave up rice for a week in your 20s and your skinny jeans immediately fit amazing again? Well, now you'll need more elbow grease and time to achieve that. Your body undergoes bone and muscle loss when you reach the third decade of your life, which leads to your metabolism running slower, but you can get your it active again by incorporating slow reps of weight-lifting exercises. Do not rely on cardio alone. You need to build stronger muscles to transform your body into a fat-fighting machine.

2. You're not getting enough sleep.
According to a study spearheaded by Matthew P. Walker, a psychology and neuroscience professor at the University of California, Berkeley, the brain instructs your body to crave junk food when you stay up late. Another study made by sleep researchers from the University of Colorado revealed that people gained an average of two pounds after being sleep-deprived for a few consecutive nights. Kenneth Wrightdirector of the university’s sleep and chronobiology laboratory explains, "We found that when people weren’t getting enough sleep they overate carbohydrates."

It was also discovered that sleep-deprived people gained more calories from midnight snacks compared to any meal they ate during the day. So if you have to burn the midnight oil, surround yourslef with healthy foods like nuts and fruits, or practice portion control if you really want that bag of chips.

3. You're not focused on getting fit.
We understand that with so much going on in your 30-something life, having a balanced diet seems impossible. It's likely that there aren't enough healthy choices during lunch break or maybe you like having sumptuous dinners and cocktails with your friends regularly either. And with road congestion getting worse every day, you'd rather wake up to get dibs on EDSA's traffic-free state before rush hour than squeeze in a 15-minute workout in the morning.

There is no shortcut to being toned and trim, so there's no other way to achieve that body you've always wanted than to get yourself to make wiser and healthier choices. Begin with baby steps like choosing whole wheat bread over white bread or slowly reducing your alcohol intake. Whether you prefer gym time or sports, devote your weekends to an activity that will get your ass moving. If your willpower is great, you'll get to your goal.

PHOTO: Flickr Creative Commons/Martin Cooper