The combined effect of improving sleep, exercise and diet simultaneously is greater than the sum of making each change in isolation, according to new research tracking nearly 60,000 people over eight years.
The study, published in the journal eClinicalMedicine, found that those with the unhealthiest habits would need five times as much additional sleep per day — 25 minutes — to achieve the same benefit as making modest improvements across all three behaviours together.
Researchers analysed data from participants in the UK Biobank cohort recruited between 2006 and 2010, then used statistical modelling to estimate lifespans and years of good health across different combinations of behaviour.
The findings suggest that people with the poorest habits could add a year to their life through minimal adjustments: an extra five minutes of sleep, two minutes of moderate to vigorous activity such as brisk walking or taking the stairs, and an additional half serving of vegetables daily.
More substantial combined improvements — 24 additional minutes of sleep, 3.7 minutes of moderate to vigorous physical activity and a 23-point increase in diet quality score — were associated with four extra years of life.
The optimal combination of behaviours, comprising seven to eight hours of sleep, more than 40 minutes of daily moderate to vigorous activity and a healthy diet, was linked to more than nine additional years of lifespan.
Diet quality was measured using a scoring system based on intake of vegetables, fruits, grains, meats, fish, dairy, oils and sugar-sweetened beverages.
While previous research has established links between individual lifestyle factors and longevity, these have typically been studied separately. The new research assessed the minimum combined improvements needed to achieve clinically meaningful gains.
The researchers noted that additional studies would be required to determine how these findings might translate into clinical practice and public health interventions.
