Before: 165

After: 140

Puberty hit me at age 10, and suddenly I felt like the fat one in my class. Then, during the summer between fifth and sixth grade, I got boobs and hips and couldn't fit into my usual size in the juniors department.

Though I was never statistically overweight in high school or college, a running injury that hit me during my second half-marathon when I was 25 kept me off the road. My physical therapist told me to stop running and build strength in other ways, and well, I was pretty damn devastated. After not working out for several months, I went from 145 pounds to 165. And those annoying boobs became the biggest they’d ever been: size E. Even if I couldn’t admit it, I was uncomfortable, unhappy, and something had to change.

The Change

When I returned to my hometown in North Carolina over the holidays, I wondered if my parents would say anything about how I looked. I don’t see them that often, since I live in New York City, but they knew I was going through a rough time.

On the way from the airport, we stopped by my favorite Southern fast-food chain, where I ordered something fried and flaky, and popped an antacid. My mom raised her eyebrow (as all moms do) and asked if my stomach was upset. I admitted that I’d been taking a Tums with every single meal because I was getting heartburn.

She suggested that maybe changing my diet would help me feel better. It was a subtle comment, but it make me realize that if I kept on the road I was on, I would damage my long-term health. I looked back at my dad, who had survived colon cancer, and knew I had to get back in shape.

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The Food

As soon as my flight touched down in New York after the holidays, I made a get-in-shape game plan with my roommate, who also wanted to get back on track. We decided to try the Whole30, a clean-eating program that helps you identify food sensitivities.

My roommate and I planned our meals, shopped together, and were each other’s moral support when the cravings got out of control. And it wasn’t easy. The Whole30 eliminates dairy, gluten, refined sugar, alcohol (RIP wine), legumes, and basically anything processed. Instead, we ate meat, veggies, fruit, and some nuts, all in moderation. The first week felt like a perpetual hangover: I wanted sugary everything, I missed cheese something fierce, and I felt lethargic all the time. But once I got over the seven-day hump, my energy levels picked up. The desire for bad food subsided, and I started to notice my pants fitting more comfortably. By the end of those 30 days, I was down 18 inches and 11 pounds. (Enhance your weight-loss goals with Women's Guide to Strength Training.)

The Workouts

A few months before I started the Whole30, I began working full-time as the editorial director for ClassPass. I was never into fitness classes, since running was my thing, but I figured that I might find something I enjoyed in a studio.

However, it wasn’t really until I started eating healthier that I found my groove. I felt more at ease and confident in classes as the weight began to fall off. It was mid-way through January when I went to my first ever boxing class, and I felt like I found my fitness calling. Though I was actually terrible at first, the class was empowering, engaging, and, well, one hell of a workout. I started mixing boxing, boot camp classes, high-intensity interval training, and hot yoga. I quickly became a fitness junkie. I went from working out maybe twice a week to exercising almost every day.

Bored with long runs for cardio? Try interval running instead:

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Sticking With It

I'll be honest, I was a little anxious after the first round of Whole30 was over and I was officially allowed to eat whatever I pleased. But what surprised me was how little I craved the food I used to devour. I'll never forget the time I went out with one of my friends to celebrate this 30-day feat and it didn't even occur to me to reach for the bread basket on our table. While there are stressful or busy times where I eat more refined carbohydrates or fried food than normal, I actually enjoy the Whole30 dishes that I learned to make.

As for working out, it helps that I work at ClassPass. The culture is very healthy and encourages employees to work out on the daily. And when I look forward to my favorite workouts or trying a new one, it never feels hard to book a class.

The Reward

I’d argue that the best parts of Whole30 are the lasting effects. After I completed the healthy eating program, I gradually added back dairy, gluten, refined sugar, alcohol, legumes, and processed foods to see how my body responded.

I realized that I’m very sensitive to dairy. In fact, when I drank milk for the first time post-Whole30, I threw up. These days, I rarely eat dairy and am almost never bloated. Plus, those antacids are a thing of the past.

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After changing my diet, I also didn’t have the same cravings as before. Today, I probably eat clean 80 percent of the time (a girl has to have margaritas and guac!). During the course of the year, I dropped a total of 25 pounds, and I hit the lowest weight I’ve ever been. And now, I’ve maintained that weight for more than a year. I went from a size 10 to a size 4, from an E cup to a C, and I have abs for the first time in my life.

On top of all that, I could defend myself pretty easily thanks to all those boxing classes. But none of that matters quite as much as the confidence and happiness I have found since making my health a priority.

Lindsay's Number One Tip

I don't guilt myself over giving into a pizza craving one night or punish myself with a week's worth of boring salads. If I do that, I'll never teach my body healthy habits. I'm never going to have a body like Emily Ratajkowski, and that's okay. I'm strong, I can kick it in intermediate boxing, nail a yoga headstand, and still have some dairy-free ice cream every once in a while. You have to be your own super fan, and that means letting yourself live a full life.