There is science behind why you can’t resist the sweet stuff. While naturally occurring sugars, like those in fresh fruit, won’t do any harm, added sugars contribute additional calories and have no nutritional benefits. The American Heart Association recommends women consume no more than six teaspoons (100 calories) per day and men no more than 9 teaspoons (150 calories). Here is a breakdown of your body on sugar.

Brain: Too much added sugar reduces your brain’s ability to release signals of fullness, causing you to eat more. Your brain’s “pleasure center” is stimulated similar to a way your brain would be stimulated on drugs. It can be addicting.

Heart: Eating too much sugar can significantly increase your risk of dying from heart disease. A study published in JAMA found those who got 17 to 21 percent of calories from added sugar had a 38 percent higher risk of dying from cardiovascular disease compared to those who consumed 8 percent of their calories from added sugar.

Teeth: Sugar causes a build-up of plaque, which leads to tooth decay.

Weight: Sugar is high in calories—just one teaspoon is 16 calories. One Hershey’s milk chocolate bar has about 5 teaspoons of sugar. The calories add up and can lead to weight gain and other diseases like diabetes.

Skin: Excess sugar consumption can worsen skin conditions like acne. Added sugar also initiates an inflammatory process called glycation, which ages skin cells faster.

Joints: Sugar increases the levels of inflammatory messengers, called cytokines, which can cause inflammation and exacerbate the symptoms of arthritis.