our internal nagging, and that of society as a whole. Instead, we need to put back the activity that modern life has removed into our daily routines. Making up our half an hour of not being sedentary does take an effort, but at least it can be achieved in manageable 10-minute blocks, can be made part of life without having to find fresh hours in the day -- and above all has the merit of being in our control. A positive goal is always going to be far more attractive than nagging people about their eating habits, or pointing out the excess flesh. The narrow focus on obesity for government, for campaigners and for individuals needs to change, and if we just can't quite get over our obsession, at least stepping on and off the scales still counts as activity if you do it enough. Physical activity is almost always a secondary consideration, and then only because of its power to help us lose weight. But is there any hard evidence that exercise has a significant effect on weight loss? Scientists such as Gary Taubes have challenged the weight loss-exercise linkage, claiming that, counter-intuitive though it may sound, exercise doesn't actually have much to do with losing weight. He claims that the American department of health (or whatever they're called), have quietly acknowledged that exercise won't help people lose weight. However, they don't publicise this because they know that, whatever they might claim, many people only exercise because they believe