The key risk factors are tobacco use, alcohol consumption, salt intake, blood pressure, blood sugar levels and obesity.
By reducing each of these to globally-agreed targets, more than 37m early deaths around the world could be avoided over 15 years, according to the study published in The Lancet medical journal.
Scientists estimated the number of deaths that could be prevented between 2010 and 2025 by reducing tobacco use by at least 30%, alcohol use by 10%, salt intake by 30%, high blood pressure by 25% and halting the rise rates of obesity and diabetes.
Meeting the targets would reduce the risk of dying prematurely from heart disease, chronic lung disease, cancer and diabetes, by 22% for men and 19% for women.
Over the 15-year period, this was equivalent to delaying or preventing at least 16m deaths of people aged 30 to 70 and 21m among those aged 70 or older.
The aim was to look at the impact of lifestyle changes on the United Nations' "25 times 25" target to reduce premature deaths from non-communicable diseases by 25% relative to 2010 levels by 2025.
Professor Majid Ezzati, from Imperial College London, who led the study, said: "Our findings show that achieving risk factor targets will make an essential contribution to achieving the 25 times 25 mortality target. Most of the benefits will be seen in low-income and middle-income countries where as many as 31m deaths could be prevented."