Making love boosts our happiness more than anything else, a study using iPhones has revealed.

Research involving 45,000 Apple smart phone users shows having sex is the best way to feel good.

Respondents taking part posted regular updates on their level of contentedness via an app.

It showed Christmas Day is easily the happiest day of the year and people are at their most content at 1.50pm on December 25.

There was also a spike in Britain’s happiness on the day of the Duke and Duchess of Cambridge's wedding on April 29.

January 31, at 8pm, is when people are at their lowest ebb, according to the research.

The 'Mappiness' project was run by researcher George MacKerron in conjunction with the London School of Economics.

It received more than three million responses over more than a year.

The app asked users to record their activity, location and happiness up to five times a day.

The results were fed into a so-called hedonimeter that tracked the nation’s mood minute by minute.

The study confirmed a commonly held belief that the population’s mood darkens during weekdays when most are at work before improving at weekends.

Mr MacKerron told the Sunday Times: 'Through April we see a series of spikes due to the bank holidays.

'Then, on the royal wedding day itself, there was a spike at around 11am during the service and again at 1pm when William and Kate went out on the balcony.'

(Read by Emily Cheng. Emily Cheng is a journalist at the China Daily Website.)