While driving to dinner with my sister and her friend, we started talking about our summer fitness goals. My ever-busy sister said she’d be happy just to make it to yoga and go kickboxing with her boyfriend on the weekends. Her friend said she wanted to drop down to 145 lbs.

“Me too,” I said. “I’m currently at 155, down from 170 over the holidays, but since I’ve been doing a lot of strength training, my waist has dropped three sizes even though I’ve plateaued at 155. What are you doing to get down to 145?”

“Nothing. Just not eating a lot,” said the friend.

“But don’t you want to be toned and strong,” I asked.

“No, I just want to be skinny,” she said.

The concept of being “skinny” has confused me my entire life. I’m 5′ 8″ with broad shoulders, a short torso, long legs, and a giant rib cage. Skinny is not in the cards for me; sexy hourglass figure with muscle tone has always been more my style. I live an active life, enjoy eating most anything I want (though I’ve always avoided soda, too much sugar, high-fructose corn syrup, and ingredients I can’t pronounce), but even at 170 I never looked “fat” because I was fit.

I didn’t know the term “skinny-fat” existed until last year. I’ve met dozens of women who looked killer in a bikini—enviably so—but when it came time to actually do something physical, they tired easily, had poor coordination, and often felt lightheaded. I remember thinking that while they looked great, they couldn’t be healthy—and I was right.

Prone to diabetes, high cholesterol, high blood pressure, and sky-rocketing blood sugar levels, skinny-fat people are at a higher risk for stroke, heart attack, and heart disease, despite having what is considered a “healthy” body mass index (BMI). Some people have the genetics where they can eat whatever they want and remain thin, giving little thought to the quality of their food. Some people become skinny-fat by eating small amounts of unhealthy food as a way to lose weight.

Either way, skinny-fat people earned this title because while they look fit, they are actually risk for metabolic diseases due to the storage of fat around their organs. Someone whose BMI is a little high for their body type, but stays metabolically fit through exercise, will actually be less likely to encounter the aforementioned diseases despite looking more “chunky.”

As someone who was teased in the pre-internet era for being larger than other girls in grade school (i.e., I could do push-ups), I weep for today’s generation of women bombarded with media that “thin is still in.” And I’ve had discussions with women who think muscle is too mannish; they think it will make them look unattractive to men. (Personally, I’d rather look like Ronda Rousey than any threadbare, bony Hollywood actress—and I think it’s safe to say you’d have a hard time finding a guy who thinks Ronda isn’t sexy—but then again, I’ve always used fitness as a way to manage my weight. Not eating made me feel sick.)

But with summer blazing above our heads and the beach calling, I’ve watched as way too many women pound diet sodas as an alternative to water and exercise. They’ll eat a doughnut for breakfast, but skip lunch entirely to balance the calories. Some people can’t fit exercise into their busy schedules, which I understand, but many still think that lower calorie intake, regardless of what kind of calories they put into their bodies, equates healthy and beautiful. Those with stellar, thin-person genetics will live on cheeseburgers, never setting foot in a gym because they think they don’t have to. As long as it’s not on their hips, they don’t worry about the visceral fat collecting around their organs.

But maybe things are changing. A few weeks ago, I was surprised when three of my female friends came up to me and started petting my arms. We were at a wedding where I was wearing a sleeveless dress. One girl literally started caressing my right tricep and asked how I made the troublesome, saggy underarm fat that most women struggle with look so lean. “I exercise,” I said. “I take boxing classes, indoor rock climb, do bodyweight exercises at home, use kettle bells—it’s all interchangeable and really fun. And I eat foods that fuel me, not just fill me up.”

Inspired by my arms (and after punching me in the abs a few times), they all agreed they wanted to add some muscle tone to their bodies. This made me ridiculously happy for two reasons: 1) As you get older, your metabolism slows. Muscles helps raise resting metabolism, decreases the risk of osteoporosis and injury, and according to one Harvard study, the added confidence that comes from strength can help fight depression—and I want my friends to be happy and healthy; 2) More women touting tight triceps and punchable tummies means changing the standard of health and beauty in our culture. You don’t have to be a body builder to be strong (lifting weights once in awhile will not make you look like Arnold Schwarzenegger), but you will be able to open that peanut butter jar by yourself—and you’ll still look good in your bikini doing it.

To learn more about the dangers of being skinny-fat, check out this recent article in Time Magazine.