August 15, 2013 - 11:02 BST hellomagazine.com Gwyneth Paltrow is making the most of the summer, showing off her lean physique in a bikini designed by one of her best celebrity friends Stella McCartney Gwyneth Paltrow is making the most of the summer, showing off her lean physique in a bikini designed by one of her best celebrity friends. The 40-year-old actress flaunted her fabulous figure in the snake print two piece by Stella McCartney. Stella was proud to share the photo of gorgeous Gwyneth on her Instagram account. "Sexy lady in Stella swimwear! Summer never stop! x Stella," the caption accompanying the retro shot read. The makeup free mum-of-two looked carefree and happy as she jumped for joy in the picture. Gwyneth and Stella have been friends for years and are often pictured together at red carpet events with Gwyneth often sporting Stella's designs. It's clear from the snap that Gwyneth's healthy lifestyle works wonders for her. Her radiant skin and toned body are the result of her following a healthy diet and working with celebrity trainer Tracy Anderson. Chris Martin's wife is keen for others follow her healthy lifestyle too. She released her second cookbook earlier this year. It's All Good that promises to make you "look and feel great". Avoiding gluten is one of the central tenets of Gwyneth's healthy eating philosophy. Although the Sliding Doors actress devotes an entire chapter to grains, she remains deeply skeptical about them. "Every single nutritionist, doctor and health-conscious person I have ever come across… seems to concur that (gluten) is tough on the system and many of us are at best intolerant of it, and at worst allergic to it," she says. All of the recipes featured in the lifestyle guru's latest achievement are 'for the foods she eats when she wants to lose weight, look good, and feel more energetic', according to the blurb on Amazon. But the American actress admits to indulging in guilty pleasures from time to time. "I often have a glass of red wine in the evening and smoke a cigarette on a Saturday," she said "I love those moments because they are just the right amount of naughty. "That balance keeps you vibrant. You have to live your life, after all." Gwyneth started her own online lifestyle publication Goop in 2008 'to share all of life's positives', providing readers exclusive access to recipes and wellness tips as well as travel guides and fashion.