High fructose corn syrup is a common ingredient in the modern American diet, found in everything from breakfast cereals to yogurt.

Previous studies have linked this sweetener to the current obesity epidemic. Now, new research shows how consuming a high amount of fructose may affect the way the body responds to an appetite-controlling hormone known as leptin.

Leptin resistance – when combined with an unhealthy diet – can lead to weight gain.

Scientists at the University of Florida College of Medicine carried out a study on rats in which they fed the animals large amounts of fructose for six months.

They tested the rats’ response to leptin and found that those consuming more fructose had become resistant to the hormone, which balances food intake with energy expenditure.

Following this observation, the team began feeding the mice a diet that was high in calories and fat, meant to resemble a typical American diet. They found that the animals tended to gain weight.

“This study may explain how the global increase in fructose consumption is related to the current obesity epidemic,” commented lead researcher Alexandra Shapiro.

People who are looking to lower their blood sugar naturally often choose foods that are low in sugar and other sweeteners.