Where is the root of happiness located in the brain?

A study conducted at the University of Kyoto, Japan found that happy people have a larger precuneus, which is grey matter located in the back of the brain between the two cerebral hemispheres. 

The precuneus is also linked to thoughts about self, memory, and the experience of consciousness.

Several studies show that meditation increases the grey matter in the precuneus.

In the study, researchers looked at two components of happiness:
1) the moment by moment experience of happiness.
2) overall feeling of satisfaction with life.

Does unhappiness cause poor health?

People tend to think that unhappiness causes disease or illness, but a recent study shows that this is not true.

Dr Bette Liu from the University of New South Wales in Australia looked at over a million women (aged 55-63) over a 10 year span.

The researcher found that only after becoming sick did rates of happiness decrease, not the other way around.  The conclusion of this study is that poor health causes unhappiness. Dr Lie says: "We found no direct effect of unhappiness or stress on mortality".

Therefore, it makes very good sense to focus on being healthy, as a way to stay happy.

It's almost obvious that if focused on health ( good nutrition, exercise, sleep hygiene, hydration),  that happiness would follow.