People have to know that if they've wanted to lose weight, if they've wanted to get their diabetes better and get their cholesterol down, here is how it works. Beyond that point, you can't force people into changes, you have to guide them.

Overall, our population is in the worst shape it's ever been. Children are in terrible shape. We have absolutely unprecedented numbers of obese and overweight children - one in three now. A generation ago it was something like one in ten.

Not only are the studies themselves often lacking even face value, but they also drain badly needed funds away from patient care needs.

In my own life, I decided to leave meat off my plate in medical school, but was a bit slow to realise that dairy products and eggs are not health foods either.

While it's certainly true that many people think that dairy doesn't have a cost to the animal, it's because they never went to a dairy farm.

The important thing is that while heroin and cocaine and tobacco and every drug and junk food cause dopamine release, there are healthier ways that you can put this into your life. And the three big ones are intimacy ... physical activity ... and the third thing is music.

I think we have to do everything that's useful. We're doctors. Our job is to tell the truth. And it doesn't have to be embellished in any way.