Doctors, nutritionists and health experts provide a wealth of advice on things you can change to make your life happier- from losing weight to ditching one food, taking up exercise to quitting alcohol.
Now six leading experts have set out the one key change they believe is most important if you want to lead a healthier and happier life - with some interesting results.
The advice costs nothing, and many of their changes cost nothing - from simply stepping outside your door to making time for yourself.
The advice is designed to boost your health and happiness. Get outdoors Doctor Thomas Pontinen said: "As a physician, outdoors enthusiast, and mountaineer going for the seven summits, I'm convinced that the easiest way to live a healthier, longer, and happier life would be to increase time spent outdoors.