For most of human history, consumption of sugar, in refined form, was virtually zero. This slowly began to change about 2,000 years ago with the discovery of sugar cane. However it is only in the last couple of hundred years that there has been a profound change in this regard.
By 1700 average consumption of sugar in the developed world was approx 4 pounds per annum and this accounted for less than 1% of calorie intake. By 1800 this had risen to approx 18 pounds and by 1900 it was 60 pounds. It currently stands at over 100 pounds per annum. At this level it accounts for a staggering 20% or one fifth of all calories consumed. In some countries the consumption is even higher,with Brazil and Israel topping the chart at approx 130 pounds per annum.
Although the sales and use of granulated sugar has reduced somewhat in recent years (people are adding less sugar to their food and beverages) the actual consumption has gone up. This is because people are consuming more processed foods and sodas, and these can contain surprising amounts of hidden sugars. In addition new forms of sugar including glucose, dextrose and hfsc (high fructose corn syrup) are been added to foods and soda drinks.
Does this matter? Part of the problem is that our bodies are not designed to consume such large quantities of refined and pure carbohydrates. With the exception of honey the are rare in nature and most foods have a lower glycemic index. This means that the carbs are released more slowly into the bloodstream, and over a longer period of time. Releasing large quantities of sugar into the bloodstream creates a shock to the system, and the body reacts by producing insulin. This can put a strain on the pancreas and liver and over time lead to the development of diabetes.
Another problem is empty calories. If 20% of all calories consumed contain no minerals or vitamins, then the nutrients the body requires for health must come from the other 80%. And if large quantities of this are low quality processed foods it makes the situation even worse.
So a reduction in the consumption of sugar is desirable. How much? Well that is a personal decision. The USDA recommends no more than 10 spoons of added sugar per day. Most Americans are consuming double this amount of sugar as well as the same quantity again of hfcs. In other words 4 times the guideline!!
Despite the impression sometimes given, sugar is not poisonous, it will not rot your bones and if taken in sensible quantities it will likely do you no harm at all. But what is a sensible quantity?
It would be a good idea to limit consumption of sugar to no more than the equivalent of 20 spoons per day from all sources including honey and fruit juices. These too create a glycemic shock as they hit the bloodstream quickly. (Just because something is natural doesn't mean you can safely consume it in large quantities.)
In addition a diet rich in unrefinedcarbohydrates (whole grains, vegetables, unsqueezed fruit etc) has been proven to have many advantages and has been linked to a reduction in obesity, diabetes, heart disease, strokes, high blood pressure and even cancer.
Habits are formed over time. Even a small change can make a difference. Gradually replace an orange juice with a whole orange or a banana. Cut down on sugar in tea or coffee. Become aware of the amount of sugar added to common processed foods. Even small changes such as these can lead to a significant improvement in overall health in the longer term.
Some useful tips regarding diet and lifestyle are available at this websitewhich discusses blood sugar level and health.