Hello and welcome to the intelligence on Economist Radio. I'm your host, Jason Palmer.

Every weekday, we provide a fresh perspective on the events shaping your world.

The dictum is simple. If you want to lose weight, eat fewer calories.

But experience and increasingly science show that it's just not as simple as that.

We take a look at what might be the most misleading measure in human health.

And today, Uber is going public.

The taxi industry is an old one,

and each time it's been disrupted, ruthless competition draws in the regulators.

We journey back to 17th century London to draw lessons for modern-day ride-hailing firms.

But first... Just as it seemed China and America were on the verge of striking a deal, the trade war has deepened.

At midnight in Washington, Friday at noon in Beijing, America announced an increase

in tariffs on billions of dollars worth of Chinese goods. Earlier in the week, President Donald Trump

had appeared sanguine. By the way, you see the tariffs we're doing? Because they broke the deal.

They broke the deal. And look, President Xi is a friend of mine.

Great guy, but he's for China.

I'm for the USA.

I'm for the USA.

So we're going to see.

They come in tomorrow and whatever happens, don't worry about it.

It'll all work out. You know why? It always does, don't worry about it. It'll all work out.

You know why?

It always does.

...