Heidi Klum Weight Loss & Workout Secrets: 42-year-old Supermodel Shows Off Sexy Butt For Her Latest Swimwear Line

Heidi Klum is no stranger in going public clad only in her sexy bikinis. But carrying it out at 42 and still pulling it off, it seems like there is no stopping her from doing what she does best.

The German supermodel and TV personality posed for some photos recently where she flaunts her sexy butt cheeks for some promotional campaign. And, we could say that some good things really last.

"Big things to come... Heidi Klum Swim launching this summer," she captioned on one of her Instagram posts where she revealed of her plans of launching her swimwear line, in partnership with New Zealand brand Bendon this coming summer.

"When you're in a swimsuit you are as close to naked as you can get, so I want to make sure women feel good and not vulnerable," she said via the Hollywood Life. "The line also has to perform really well. I go to water parks a lot with my kids and you want things that look good but that also hold up when they are wet."

According to the Celebrity Health and Fitness, Klum's secrets to looking fit and young despite her age include a low-carb diet and rigorous workouts, such as circuit-training, cardio exercise and weightlifting.

"I'm pretty good about not eating too many carbs," she said. "I love vegetables. I don't eat bagels-no way! A bagel is basically a cardboard box. Usually I'll have a smoothie in the morning."

Her diet also includes a lot of fresh vegetables and fruits, while she tries to keep herself away from consuming processed foods. She also likes incorporating foods packed with lean proteins. And, of course, she is also into home-cooked German meals.

And, it seems like Klum is right on point when it comes to getting fit. According to some experts, gaining weight is not so much about calorie intake as it is about consuming foods high in refined carbs and sugars. When you take in too much sugar and processed grains in your body, it tends to store more fats because of the insulin spikes.

For her workouts, Klum does a combination of circuit-training workouts, strength-training, lunges, step-ups and rows every day. She also does some ab exercises to keep her flat tummy and do some running on the treadmill for half an hour at the convenience of her home. She also makes it a point to do some hiking with her children whenever they are in Los Angeles.