Hitting those goals! Adele has undergone a major weight loss transformation and she’s not shy about sharing her story, opening up to a fan about how many pounds she’s shed.

The “Hello” songstress, 31, was spotted looking much slimmer while on vacation in Anguilla with Harry Styles and James Corden on January 3.

Meredith Noonan was also vacationing in Anguilla with her family when she unexpectedly ran into Adele and Styles, 25. The Fordham University School of Business student told Us Weekly exclusively that the Grammy winner told her how much weight she has dropped.

“When she introduced herself and began asking us about ourselves and our vacation in Anguilla, I apologized for not recognizing her right away and she said, ‘Don’t worry, I’ve lost around 100 pounds,” Noonan recalled. “We told her how great she looks. She seemed very happy and relaxed, totally enjoying her vacation! We didn’t talk about how she lost it.”

Noonan added that Adele looked “really comfortable in her own skin” and was “so down-to-earth and outgoing.” The college student said that the singer was enjoying her getaway with friends, who included her good pal Styles.

“The most unexpected part was Adele walking over and sitting down with us, and then asking Harry to come over,” she said. “Both Adele and Harry were so genuine and it’s nice to get a glimpse of who they really are.”

Adele has gotten plenty of attention for her slender frame over the past few months. She first showed off her new body when posing for a picture with the Spice Girls in June. A few months later, she arrived at Drake‘s birthday party looking a few pounds thinner in a cinched black dress.

Adele’s former Pilates instructor, Camila Goodis, told Us on Friday that it appears the “Rolling in the Deep” singer lost the weight mainly through a change in diet.

Goodis, who trained Adele after she gave birth to her now 7-year-old son Angelo, said she did not contribute to Adele’s current weight loss but it appeared Adele shed the pounds in a healthy way.

“Do I think that she exercised crazy? I don’t,” Goodis said. “I think she did change her lifestyle, like eating better, exercising moderately. The path to lose weight is not really a lot of exercise. It’s actually your mouth. And I tell all my clients, ‘You can exercise 10 hours a day, if your diet is poor, you’re not going to see success.’ That’s the real truth.”

Registered dietitian and physician assistant Heather Struhl, who estimated Adele lost approximately 70 pounds, echoed a similar view in an interview with Us on Wednesday, January 8.

“Initially, if several pounds of weight loss occur rapidly, this can be a loss of water weight. For Adele, this appears to have been a gradual weight loss over the past several months, which is optimal for health,” she said.

With reporting by Marc Lupo