If there’s anyone who knows a thing or two about sustainable dieting, it’s Dr Xand van Tulleken – the Harvard and Oxford-educated doctor and scientist lost a whopping seven stone and has managed to maintain a healthy weight ever since. Dismissing clean eating and championing counting calories, his straight-forward approach is scientifically proven and hassle-free, cutting through various health claims to deliver simple, everyday tips. Here’s his advice for how to lose weight the healthy way…