Sugar is evil, but until recently people said the same of all kinds of fat. Calories and BMI (body mass index) have fallen under suspicion as flawed measurements. Few of us do enough exercise or consume our five portion of fruit and vegetables every day. We don't always eat because we're hungry, but to satisfy other needs – and because we cave in to the sometimes subtle and sometimes strident temptations all around us. We are easy prey for the junk food companies, followed by the diet industry.

Whatever the reasons and regardless of all the finger-wagging, the human race is growing steadily bigger and bigger. It would not matter in the least, if our increasing weight were not seriously damaging our health.

My book, The Shape We're In, published on July 3, looks at the forces around us that have brought us to this pass and what needs to be done to change the world we live in so that we can lead healthier and happier lives. It aims, above all, to stimulate debate. I hope to continue the discussion with updates, new stories and comment in this blog. Warning: I may use the f-word. Or even the o-word. Ideas for a phraseology that offends nobody are welcome, if unlikely.

There have been some important developments recently - the Lancet paper on the scale of obesity around the world, which I wrote about here. My colleague Ami Sedghi also put together a Datablog from the figures.

And in some early posts on this blog, I have looked at the recommendation that everybody who is obese or overweight in England should be paid to go to a slimming club, and also at whether local politicians are more likely to call Big Food and Drink to account than national government seem prepared to do.