It’s fun to fit into sexy jeans or a little black dress. But here’s the biggest reason to slim your waistline: It can help you live longer.

Admit it, ladies. We all want to whittle our waists so we can totally rock a little black dress. We want the other women in yoga class to hate us for flaunting sexy abs. And we want to slide into our jeans instead of lying on the floor gasping for breath as we battle that zipper. (Yeah, I’ve been there.)

But now there’s an even more important reason for you to make a slim waist a top priority: It can save your life.

This week, a shocking finding by British researchers made headlines around the world. The researchers studied nearly 93,000 women, using a simple metric: skirt size. Here’s what they found.

• Women who gain a skirt size every decade between their 20s and 60s have a 33% greater risk of developing breast cancer after menopause.
• Women who gain two skirt sizes every ten years have a 77% greater risk.

And breast cancer isn’t the only disease linked to a thickening waist. It also puts you at higher risk for pancreatic, ovarian, and endometrial cancer.

Scary? Yes. But don’t be scared. Instead, take action. If you’re fighting the battle against belly fat right now, here’s a simple strategy for victory:

• Cut sugar, flour, and grains out of your life. And that includes so-called “healthy” grains. These foods make your insulin levels skyrocket, and insulin promotes fat—especially belly fat.
• Ditch your low-fat diet and instead eat a smart-fat diet rich in foods like avocados, salmon, pastured beef, and coconut oil. Studies show, over and over again, that people lose more weight on a low-carb diet than on a low-fat diet.
• Center your diet around high-quality proteins and nutrient-dense veggies. These foods encourage your body to form lean muscle mass and burn off fat.
• Do strength training. Unlike cardio, strength training can sculpt your stomach muscles and turn ”jelly” into lean muscle.
• An optimal vitamin D level is critically important in minimizing your cancer risk; a study of post-menopausal women showed that maintaining vitamin D serum levels of 40ng/ml cut overall cancer risk by 77 percent.

Just by following these simple steps, hundreds of my female patients are transforming their bodies. Within weeks, they lose inches off their bellies. Within months, many go from “apple” to “hourglass” figures.

So if you’re on the verge of surrendering to a bigger skirt size, just say no. Better yet, say, “Hell, no.” Instead, commit to following my belly-fat-blasting battle plan for two months. I’m betting you’ll lose a skirt size instead of gaining one.

So what have you got to lose? A skirt size. What have you got to gain? A longer life.

Oh, yeah. And you can totally rock that little black dress.

Keep thinking big and living bold!

-Dr.Kellyann