Headlines from every corner of the internet have told us: We eat too much sugar. After all, this addicting sweet substance is added to just about everything we see on supermarket shelves.
If you’ve scrolled through dozens and dozens of tips about cutting down on sugar with glazed eyes—and then proceeded to order that glazed donut with your coffee the next morning—allow us to (gently) shake you out of your caramel macchiato-induced daydream. There’s no debating it: A diet loaded with sugar can lead to some serious health issues.
Here’s everything you need to know about how too much sugar affects your body long-term—along with expert advice for making sure your sweet tooth doesn’t derail your diet and health.
Weight gain is rampant in the U.S., with over a third (yes, a third) of Americans suffering from obesity. One of the epidemic’s major contributors? Too much sugar.
When you eat sugar, it enters your blood stream and signals your pancreas to produce the hormone insulin, which transports it to be used as energy or stored in your liver, muscles, or fat cells. However, when you consistently eat too much of the sweet stuff, it can’t all be utilized and begins to overwhelm your system—and ends up being stored as fat.
Simply put, this type of energy imbalance (along with other factors, like genetics, lack of sleep, and lack of exercise) leads to obesity. In fact, one 2013 BMJ review found that people with the highest intake of sweetened drinks were almost twice as likely to be obese than those with the lowest intake.
2. Type 2 Diabetes
Perhaps the most well-known of the conditions related to a sugar-laden diet is type 2 diabetes, a chronic illness marked by excess sugar in the blood.
Type 2 diabetes occurs when either the pancreas can no longer produce enough insulin (the hormone that transports sugar) to send sugar from the blood to the cells, or when so much insulin has been churned out over time that the cells themselves become resistant to its effects (called ‘insulin resistance’).
While consuming excess sugar alone doesn’t directly cause diabetes—activity level, family history, race, age, and other health conditions all contribute—it does seem to be a big part of the problem. For example, one study published in Diabetes Care found that people who drank one or two sweetened beverages (think soda, ice tea, energy drinks) per day were 26 percent more likely to develop diabetes than those who did not.
People with type 2 diabetes often experience weight gain, fatigue, and excessive hunger and cravings. Type 2 diabetics are also at greater risk for kidney damage, nerve damage, bladder problems, heart disease, and stroke—which leads us to…
3. Heart Disease + Heart Attacks
Coronary heart disease (CHD), a condition in which plaque builds up in your coronary arteries (which supply your heart with blood), potentially leading to blood clots, heart attacks, and heart failure, is responsible for one in every six deaths in the United States. Though saturated fat was long thought to drive CHD, a paper recently published in Open Heart suggests that eating too much added sugar is in fact a primary nutritional factor.
High blood sugar and insulin resistance both increase risk of CHD, as excess sugar that’s stored as fat can enter the blood stream and begin to clog arteries, says Vanessa Rissetto, R.D.
According to that Open Heart paper, sugar’s impact is significant. In fact, those who get more than 25 percent of their total calories from added sugar are three times more likely to die from a cardiovascular disease-related issue than people who eat fewer than 10 percent of their calories from added sugar.
4. Nonalcoholic Fatty Liver Disease
Like its name suggests, nonalcoholic fatty liver disease (NAFLD) occurs when excess fat builds up in liver cells for reasons other than heavy alcohol use. In its severe form, it can involve inflammation and permanent damage to the liver, and even lead to liver failure. According to the University of California San Francisco, over 31 percent of American adults suffer from the disease.
Though NAFLD isn’t fully understood, it has been linked to being overweight or obese and having high blood sugar or type 2 diabetes, according to The Mayo Clinic. Fructose, a type of sugar that occurs naturally in fruit and is added to many processed foods, seems to be particularly problematic. Unlike other sugars, fructose is processed in the liver, and when consumed in large amounts, appears to be toxic to the liver, just like alcohol.
People with NAFLD may feel fatigued and experience pain in the upper right abdomen—but often don’t have symptoms at all. Experts recommend a plant-based diet, plenty of exercise, and weight control for preventing this condition.
5. Cognitive Decline And Alzheimer’s
In recent years, a growing amount of evidence has linked blood sugar issues to dementia and Alzheimer’s disease.
Studies have identified that those following high-sugar diets performed worse on cognitive tests, with one Neuroscience study finding that a diet high in refined sugar can reduce levels of a protein called BDNF in the hippocampus, which is the part of the brain associated with memory.
What’s more, type 2 diabetes has been linked with greater risk of Alzheimer’s, a progressive disease that affects memory, thinking, and behavior, in which people eventually lose the ability to converse or respond to their environment.
Though the origins of Alzheimer’s are not completely understood, one 2017 Scientific Reports study found that sugar can damage an enzyme called MIF, which plays a key role in the immune response necessary for us to ward off the disease.
Cut Sugar, Cut Your Risk
This is scary stuff—but it doesn’t mean you can never enjoy something sweet again. Like everything else, just enjoy the sweetness in moderation, eat as many whole foods as possible, and try to avoid pre-packaged processed foods and snacks, which are often loaded with refined sugars, says Rissetto.
The American Heart Association, recommends a max of 100 calories (or 25 grams) of added sugar per day for women and 150 calories (or about 37 grams) per day for men. (For reference, your average glazed donut from Dunkin’ contains 12 grams.)
Of course, the occasional treat is okay, but when sugar cravings strike, try reaching for fruit or dark chocolate, and swapping table sugar out for maple syrup or honey, which contain antioxidant compounds called polyphenols, suggests Jackie Ballou, R.D., owner of Balancing Act Nutrition.