What simple sugar in large quantities have been shown?

The simple sugar that, when consumed in large quantities, has been shown to be detrimental to health is fructose. Fructose is a monosaccharide, the simplest form of sugar, which occurs naturally in fruits and vegetables. It is also used as a sweetener in many processed foods and beverages.

Consuming large amounts of fructose has been associated with various adverse health effects, including:

1. Metabolic syndrome: High intakes of fructose have been linked to metabolic syndrome, a cluster of conditions that increase the risk of chronic diseases like heart disease, stroke, and type 2 diabetes.

2. Insulin resistance: Excessive fructose consumption can impair glucose metabolism and lead to insulin resistance, a condition where cells do not respond properly to the hormone insulin. This can increase the risk of developing type 2 diabetes.

3. Increased triglyceride levels: High levels of fructose can elevate blood triglyceride levels, which are a type of fat that can increase the risk of cardiovascular disease.

4. Weight gain and obesity: Fructose is often found in sugary drinks and foods high in calories. Excessive consumption of these foods can lead to weight gain and obesity, contributing to several health problems.

5. Non-alcoholic fatty liver disease: Excessive fructose intake has been associated with the development of non-alcoholic fatty liver disease (NAFLD), a condition where fat accumulates in the liver.

It's important to note that while fructose can be harmful when consumed in excess, moderate intake of fruits and vegetables that naturally contain fructose is generally considered safe and can provide numerous health benefits due to other essential nutrients they offer. The primary concern lies with the excessive consumption of added sugars, particularly in processed foods and sugary drinks, which contribute significantly to the various health risks associated with high fructose intake.