A U.N. study says non-infectious diseases are responsible for nearly two-thirds of all deaths across the globe.

The study says over 36 million people die each year from noncommunicable diseases, the deadliest of which are lung and heart disease, cancer and diabetes.

The study cites lack of physical activity, abuse of tobacco and alcohol, and unhealthy diets as primary reasons for the increase. Nearly 80 percent of the deaths occurred in developing countries.

The report says that deaths resulting from noncommunicable diseases have gone relatively unnoticed because the international community has instead focused on preventing infectious diseases such as HIV/AIDS and malaria.

The U.N. will sponsor a summit in September that aims to formulate a global strategy to combat noncommunicable diseases.