High salt intake - which averaged 5.4 grams daily in 2011 - was blamed for 20 percent of cardiovascular disease cases in China.

The increases in hypertension and BMI were more prevalent among younger people and rural residents, the authors said.

"Our estimates suggest that the continued rise in high blood pressure, an increasingly sedentary lifestyle, increasing obesity and worsening dietary trends will add millions of new cases of heart attacks and stroke over the next two decades," said Yanping Li, research scientist in the Department of Nutrition at Harvard Chan School and the study's lead author.

The researchers analyzed data collected from 1991 to 2011, from 26,000 people in nine provinces, as part of the China Health and Nutrition Survey.

They looked at 17 dietary and lifestyle risk factors, including high systolic blood pressure, high cholesterol, high blood sugar, high BMI, low physical activity and smoking, along with 11 dietary factors, and analyzed data from the China Health Statistical Yearbook and the National Population Census.

The study found that high blood pressure, high cholesterol and high blood glucose accounted for most cardiovascular disease cases in China in 2011. The three risk factors were associated with 3.1 million, 1.4 million and 0.9 million new cases, respectively, of heart attack or stroke.

Of the 6.8 million Chinese over age 35 who died in 2011, about 3 million - 44 percent - were related to cardiovascular disease.

The researchers contend that high blood pressure was responsible for roughly 40 percent of heart attacks or stroke. In 1979, high blood pressure, or hypertension, was found in 7.7 percent of the population; by 2010, it was 33.5 percent - comparable to the rate among US adults.

"Prevention of chronic diseases through promoting healthy diet and lifestyle should be elevated to a national public policy priority," said senior author Frank Hu, professor of nutrition and epidemiology.