Actually, the number one cause of heart disease and hypertension is obesity, since fat deposits block the flow of blood to the heart, increasing the likelihood of a heart attack. Heart disease is the leading cause of death in American men.
Refined sugar is very unhealthy, but in terms of obesity and its attendant dangers, the real culprit is cholesterol and fat, particularly animal fats. Many doctors recommend that obese or hypertensive patients dramatically lower their consumption of red meat or switch to a vegetarian diet.