7 Reasons Why Eating Too Much Processed Sugar Is Harming Your Health

From marinara sauce to peanut butter, added sugar hides in more foods than most people expect. In the United States, the average adult consumes about 17 teaspoons every day, which is roughly 14 percent of total daily calories. That is far above the recommendation from both the American Heart Association and the U.S. Dietary Guidelines to keep added sugar under 10 percent. Consistently going over that limit does not just cause weight gain, it can have wide-reaching effects on almost every part of the body.

1. It Contributes to Weight Gain

Sugary drinks and processed snacks pack in a lot of calories but do not do much to make you feel full. One reason for this is fructose, a type of sugar found in many sweetened drinks and desserts, which seems to blunt the effect of leptin, the hormone that signals to your brain that you have eaten enough. When your brain is not getting that “I’m full” message, it is easy to keep eating and drinking past what your body needs. Over time, the extra calories encourage weight gain and the buildup of visceral fat, the deeper abdominal fat linked to heart disease and type 2 diabetes. An easy way to make a difference is to replace one sugary beverage a day with water, sparkling water, or unsweetened tea, cutting out hundreds of empty calories a week without feeling deprived.

2. Increases Risk of Heart Disease

Too much added sugar also affects the heart in ways that go far beyond weight. Diets high in sugar are linked to higher triglyceride levels, lower “good” HDL cholesterol, increased blood pressure, and more inflammation in the arteries. Each of these factors raises the risk of heart disease and stroke. In a study involving more than 25,000 adults, people who consumed the most added sugar were significantly more likely to develop heart problems than those who consumed the least, even when weight differences were accounted for. This shows that it is not only about calorie control, sugar itself is affecting the heart and blood vessels directly.

3. Raises Your Risk of Type 2 Diabetes

Over time, too much sugar can push your body toward insulin resistance, which is when your cells do not respond well to insulin, the hormone that helps move sugar from your bloodstream into your cells to be used for energy. As blood sugar levels stay higher for longer, your pancreas has to work harder to produce more insulin, and eventually this process can lead to type 2 diabetes. Long-term research shows that people who drink at least one sugary beverage a day have a 20 to 26 percent greater risk of developing diabetes compared to those who rarely drink them. Cutting back on sweetened drinks is one of the most effective ways to lower that risk.

4. Promotes Fatty Liver Disease

Fructose is processed almost entirely in the liver, and when there is too much coming in, the liver begins converting it into fat. Some of that fat stays in the liver itself, leading to a condition known as non-alcoholic fatty liver disease, or NAFLD. This condition often develops with no obvious symptoms, but in some cases, it can progress to liver inflammation, scarring, or even serious liver damage. Studies have found that people who drink sugary beverages every day have more than a 50 percent higher risk of developing NAFLD. Scaling back on sodas, sweet teas, and other high-fructose processed foods gives your liver the breathing room it needs to function properly.

5. Negatively Impacts Mental Health and Mood

A high-sugar diet does not only affect your body, it can also influence your mood and mental wellbeing. Researchers have linked excessive sugar intake to higher rates of anxiety, depression, and poorer mental clarity. Part of this may be due to inflammation in the brain and changes in how neurotransmitters like dopamine work, but the rapid spikes and drops in blood sugar also play a role in leaving you irritable or fatigued. In a long-term study of more than 8,000 people, men who consumed the most sugar were significantly more likely to develop depression within five years. Reducing sugar can help keep your mood and energy levels more stable throughout the day.

6. Accelerates Skin Aging

Consistently high blood sugar levels lead to the formation of compounds called advanced glycation end products, or AGEs. These compounds damage collagen and elastin, which are the proteins that keep skin firm, smooth, and elastic. As these proteins weaken, the skin loses structure and becomes more prone to wrinkles and sagging. While everyone’s skin ages over time, high sugar intake can make that process happen faster. Keeping sugar consumption in check, along with eating antioxidant-rich fruits and vegetables, can help slow these effects and protect skin health.

7. Causes Energy Spikes and Crashes

Eating or drinking something high in sugar causes a rapid rise in blood sugar, giving you a short boost of energy. The body often responds by producing extra insulin to bring the levels back down, sometimes overshooting and leaving blood sugar lower than before you ate. This “sugar crash” leaves you feeling tired, irritable, and craving more sweets. Choosing snacks that combine carbohydrates with protein or healthy fats, such as an apple with nut butter or whole grain toast with avocado, slows the release of sugar into your bloodstream and helps your energy levels stay steady for longer.

The Bottom Line

Too much added sugar affects multiple systems in the body, from the heart and liver to the skin and brain. The good news is that even small steps to cut back, such as replacing a daily soda with water or skipping syrup in coffee, can quickly begin to improve your health. Sticking closer to the recommended limit of less than 10 percent of daily calories from added sugar helps protect against chronic disease, supports steadier energy, and can keep you feeling and looking your best for years to come.

References

1. CNN, "Study finds 45 negative health effects of added sugar" (2023)
2. NIH PMC5133084, "Relationship between Added Sugars Consumption and Chronic Diseases" (2016)
3. The BMJ, "Dietary sugar consumption and health: umbrella review" (2023)
4. Harvard Health Publishing, "The sweet danger of sugar" (2022)
5. Nature, "The time has come to reconsider the quantitative sugar guidelines" (2024)
6. ScienceDirect, "Intake of Added Sugar from Different Sources and Risk of All-Cause Mortality"
7. NIH PMC9966020, "The Impact of Free Sugar on Human Health" (2023)
8. CDC, "Get the Facts: Added Sugars" (2024)
9. Harvard Health, "The bitter truth about added sugar" (2023)
10. ScienceDirect, "Added sugar intake is associated with weight gain and risk of obesity"