Question

how does obesity and intake of alcohol and drugs affect the heart ?

Answer 1

Obesity is linked to increased fats in the body causing thickening of walls of blood vessels due to fat deposition. Thickening of blood vessel wall leads to high blood pressure, atherosclerosis which are the causes of heart attack.
Alcohol consumption in high amount leads to high blood pressure, obesity, strokes etc. All these affect heart.
Drugs such as cocaine are associated with increased heart beat, stroke, inflammation of heart muscles, increased blood pressure etc. affecting heart.