Sugar has its health benefit and implication, which all depends on how we consume it and the total amount present in our body.
On the 1990, lots of infomercials focused on educating consumers best way possible to stay healthy.

Sugar is poisonous and toxic if taken in excess without moderation.
It’s clear in our modern age now that people eat too much processed food, and the people who are processing such food for us are putting an enormous amount of sugar into it, allowing us consume a lot of sugar than average.

There are lots of health consequences eating too much sugar such as;

Cardiovascular disease
Stroke
Higher Cholesterol and triglycerides
http://healthful.com.ng/the-sick-trait-of-sugar/