Is mono unsaturated fat healthier than polyunsaturated fats? which one will affect our diet more? and why is that so?

Tough to say: According to recent research studies, there is no conclusive evidence that mono unsaturated fat is healthier than poly unsaturated fat. They are both healthier than saturated fat, which is found mostly in animal fat. Unsaturated fat tends to lower bad cholesterol and makes less cholesterol plaques which cause blockages in the arteries.