Happiness, Dr Rangan Chatterjee, believes can transform our health - and is the missing piece of the puzzle around public health. But too many of us, he says, mistake success for happiness. You can also work towards it, as he outlines in his book, Happy Mind, Happy Life, and in an interview in the Herald magazine. Here are some of his key tips:

“I see happiness or what I call core happiness as a three legged stool. Each of the legs are separate, but they're each essential. And if any one of those legs starts to weaken, your feelings of happiness will start to diminish and ultimately start to collapse. And the three legs are alignment, contentment and control.”

"Feeling aligned means that the person you want to be, the person you are actually being out there are one and the same. You're aligned when your inner values and your day-to-day actions match up."

READ THE FULL INTERVIEW: Why Rangan Chatterjee believes happiness is the key to making us healthier

“I was reluctant to use the word control. We can't control the world. The last two years has shown us that. Things are gonna happen whether we like them or not. It's about what can you do it gives you a sense of control over your life. And for me, that's the key thing you know, whether it's a little routine or journaling or saying hi to the barista at the coffee shop, which gives your brain a sense of control that your external world is safe.”

“Work happiness habits into your life. One way of working out what these might be is to imagine yourself on your deathbed and looking back on your life. What are three things I will want to have done in my life? Once you know that, you can go and figure out what whatever happiness habits you need to do regularly to give yourself that happy ending you've just defined that you want."

“When I did these myself I found I would like to have spent a lot of time with friends and family, done something that contributes to the wellbeing of other people in the wider world and spent time on things I am passionate about like playing my guitar or playing snooker or going for a run, so I developed weekly habits that would help me do this. One of these was having five meals a week with my wife and kids where I am fully present."

Dr Rangan Chatterjee will be speaking at The Queen’s Hall, Edinburgh on May 16 at 7.30pm. His new book, Happy Mind, Happy Life: 10 Simple Ways to Feel Great Every Day, is out now.