Researchers claim that those who regularly get a good night's sleep enjoy an improvement in wellbeing greater than the impact of a four-fold increase in spending money. "Sleep was the strongest indicator of a broader sense of wellbeing," they said.
"The majority of those with the highest Living Well scores reported feeling well rested most of the time, while more than half of those in the bottom 20 per cent of the Index said that they rarely, or never, felt well rested."
Across the population, just over a third (35 per cent) said they were fairly or very satisfied with their sex lives. The study stated: "Once again, these individuals were disproportionately likely to be found at the top of the Living Well Index - with almost two thirds (63 per cent) of those at the top saying that they were satisfied with their sex life, twice the national average."
Researchers revealed job security ranked number three in a measure of wellbeing.
"Among working people, 43 per cent of those with the highest Index scores also experience a very high degree of job security, almost twice the national average," they explained.
The study found most people are more concerned about the health of close relatives, rather than their own ailments. And being part of a community can offer much more comfort than having money in the bank.
Typically, the study funded by Sainsbury's found that people speak to their neighbours once or twice a month. By contrast, those most happy with their lives chat to neighbours at least once or twice a week.
Director of Consulting at Oxford Economics Ian Mulheirn said: "The analysis within the Sainsbury's Living Well Index reveals that, in a world that's never been more connected, the richness of our relationships and support networks remains among the biggest determinants of how well we live..."
Sainsbury's chief Mike Coupe said the index would "help to inform how we run our business and will also help us uncover and engage more boldly on the issues that concern people most in their everyday lives."
