Why Is Sugar Bad For Your Health?

Sugar is bad for your health because it drives insulin resistance, weight gain and inflammation. These raise your risk of type 2 diabetes, heart disease, kidney disease and gout. Sugar also spikes and crashes your blood sugar. That drains your energy, feeds cravings and crowds out essential nutrients.

Chances are you already know that eating too much sugar isn’t good for you. Yet you’re probably still overdoing it. Sugary drinks, candy, baked goods, and sweetened dairy are the main sources of added sugar. Added sugars can be hard to spot on nutrition labels. That is because they can be listed under a number of names, such as corn syrup, agave nectar, palm sugar, cane juice, or sucrose. No matter the name, sugar is sugar, and it can negatively affect your body in many ways. Here’s a closer look at how sugar can affect your health negatively.

What are the negative effects of sugar?

How much sugar a person should eat varies, depending on their sex and age. Sugar appears in our food in many forms, including sucrose, lactose, and fructose. Sweet as it is, it sometimes has a negative impact on our health. Let’s look at some of these:

1. Can cause weight gain: Rates of obesity are rising worldwide. Added sugar, especially from sugar-sweetened drinks, is thought to be one of the main culprits. Sugar-sweetened drinks like sodas, juices and sweet teas are loaded with fructose, a type of simple sugar.
2. Can drain your energy: Your glucose levels spike and plummet. Because of this, the unstable blood sugar can leave you with mood swings, fatigue, and headaches. It also contributes to cravings, which begin the cycle of false hunger. By contrast, those who avoid sugar report fewer cravings and feel more emotionally balanced and energized.
3. Sugar affects cognition in children: Let’s not forget about our little ones! New York City public schools reduced the amount of sugar in their lunches and breakfasts. When they did, their academic ranking increased by 15.7% (before that, the greatest improvement ever seen had been 1.7%). The study also removed artificial colors, synthetic flavoring, and two preservatives, showing the importance of natural ingredients for children.
4. Increases Your Risk of Type 2 Diabetes: There is a clear link between eating too much sugar and diabetes risk. Obesity, which is often caused by eating too much sugar, is considered the strongest risk factor for diabetes. Also, prolonged high-sugar eating drives resistance to insulin. Insulin is a hormone made by the pancreas that regulates blood sugar levels. Insulin resistance causes blood sugar levels to rise and strongly increases your risk of diabetes.
5. Your immune function can be affected by sugar: As if being sick wasn’t bad enough, studies have shown that sugar can interfere with the way your body fights disease. Bacteria and yeast feed on sugar. So excess glucose in the body causes these organisms to build up and cause infections.
6. A high-sugar diet can lead to chromium deficiency: Chromium is a trace mineral that helps regulate blood sugar in the body. It can be found in meats, seafood, and plant foods. Yet 90% of Americans still don’t get enough chromium because of refining processes. Other carbohydrates can also rob foods of their chromium supplies. So limiting your carbs is your best bet for increasing those mineral levels.
7. Sugar accelerates aging: You probably know that sugars can affect your body composition. But they can also mess with your skin by contributing to wrinkles and sagging. After sugar hits your bloodstream, it attaches to proteins. The mix of these proteins with sugar causes the skin to lose elasticity and leads to premature aging.
8. Sugar causes tooth decay: With all of sugar’s other life-threatening effects, we sometimes forget the most basic cosmetic damage it does. When sugar sits on your teeth, it causes decay more efficiently than any other food. It’s important to brush your teeth at least twice a day to stop sugars from fueling plaque and bacteria.
9. Sugar can cause gum disease, which can lead to heart disease: Increasing evidence shows that chronic infections, like those that result from dental problems, play a role in the development of heart disease. The connection is believed to stem from the body’s inflammatory response to infection. Luckily, this works both ways. A healthy lifestyle will decrease your risk of common illnesses. That reduces the chance that they’ll become a more serious condition later on.
10. Sugar takes the place of important nutrients: According to USDA data, people who consume the most sugar have the lowest intakes of essential nutrients, especially vitamins A, C, B-12, and calcium. This is because the body needs these vitamins to process the sugar. The body uses up its reserves, and so “negative calories” and loss of vitamins occur. The trade-off is especially dangerous for children and teens. That is because they consume the most sugar and need the most nutrients at the same time.
11. May Increase Your Risk of Heart Disease: High-sugar diets have been associated with an increased risk of many diseases, including heart disease. Heart disease is the number one cause of death worldwide. Evidence suggests that high-sugar diets can lead to obesity, inflammation and high triglyceride, blood sugar, and blood pressure levels. These are all risk factors for heart disease. Also, consuming too much sugar, especially from sugar-sweetened drinks, has been linked to atherosclerosis. Atherosclerosis is a disease marked by fatty, artery-clogging deposits.
12. Can cause acne: Foods with a high glycemic index, such as processed sweets, raise your blood sugar faster than foods with a lower glycemic index. Sugary foods quickly spike blood sugar and insulin levels. This causes increased androgen secretion, oil production, and inflammation, all of which play a role in acne development.
13. May Increase Your Risk of Cancer: Eating excessive amounts of sugar may increase your risk of developing certain cancers. First, a diet rich in sugary foods and drinks can lead to obesity, which significantly raises your risk of cancer. Also, diets high in sugar increase inflammation in your body and may cause insulin resistance. Both of these increase cancer risk.
14. Can Accelerate the Skin Aging Process: Wrinkles are a natural sign of aging. They appear eventually, regardless of your health. However, poor food choices can worsen wrinkles and speed the skin aging process.
15. Increase kidney disease risk: Blood sugar levels that are consistently high can damage the delicate blood vessels in your kidneys. This can lead to an increased risk of kidney disease.
16. Increase the risk of developing gout: Gout is an inflammatory condition marked by pain in the joints. Added sugars raise uric acid levels in the blood. This increases the risk of developing or worsening gout.
17. Accelerate cognitive decline: High-sugar diets can lead to impaired memory. They have also been linked to an increased risk of dementia.

How can you reduce your sugar intake?

Eating small amounts now and then is perfectly healthy. But excessive added sugar has many negative health effects, so you should try to cut back on sugar whenever possible. Simply focusing on eating whole, unprocessed foods automatically lowers the amount of sugar in your diet, which has huge gains.

What are easy swaps to cut added sugar?

• Swap sodas, energy drinks, juices and sweetened teas for water or unsweetened seltzer.
• Drink your coffee black or use Stevia for a zero-calorie, natural sweetener.
• Sweeten plain yogurt with fresh or frozen berries instead of buying flavored, sugar-loaded yogurt.
• Consume whole fruits instead of sugar-sweetened fruit smoothies.
• Replace candy with a homemade trail mix of fruit, nuts and a few dark chocolate chips.
• Use real olive oil and vinegar in place of sweet salad dressings like honey mustard.
• Choose marinades, nut butter, ketchup and marinara sauce with zero added sugars.
• Skip cereals, granolas and granola bars. Most are refined grains with added sugar.
• Swap your morning cereal for eggs, or an omelet made with fresh greens.
• Instead of a jelly sandwich, spread peanut butter on apple or banana slices.
• Use natural nut butter in place of sweet spreads like Nutella.
• Avoid alcoholic beverages that are sweetened with soda, juice, honey, sugar or agave.
• Shop the perimeter of the grocery store, focusing on fresh, whole ingredients.
• Eating fruit can help ensure a person gets enough fiber, vitamins, and minerals. However, many fruits are high in natural sugars. They may not suit those looking to lower their sugar intake. Some low-sugar fruits include strawberries, peaches, blackberries, lemons, limes, honeydew melon, oranges, and grapefruit.

Is it better to never eat sugar?

Sugar is not unhealthful in itself. However, having excess sugar in the diet can cause a range of conditions, including heart disease, weight gain, and diabetes. To be aware of added sugars in food products, it is important to read labels carefully. Also, eliminating sugar from the diet can help prevent weight gain, diabetes, heart disease, and other problems. For these reasons, keep added sugar to a minimum whenever possible. That is easy when you follow a healthy diet based on whole foods. If you need to cut added sugar from your diet, try some of the small changes listed above. You will slowly realize that you don’t need as much sugar as you once did.

Frequently asked questions

What are signs of too much sugar?

When blood sugar spikes and then plummets, the swing shows up as mood swings, fatigue, headaches and cravings that start a cycle of false hunger. Over time, a high-sugar diet shows on the outside too. Signs include acne from the insulin and androgen surge, tooth decay and gum disease, and skin that loses elasticity and wrinkles early. Steady weight gain, especially from sweet drinks, is another sign.

What will happen if I cut sugar out of my diet?

People who avoid sugar report fewer cravings and feel more emotionally balanced and energized. That is because their blood sugar stops swinging up and down. Cutting added sugar also helps prevent weight gain, type 2 diabetes and heart disease. Start with the small swaps above, such as water instead of soda and berries instead of flavored yogurt. You will slowly realize you don’t need as much sugar as you once did.

What kills the urge for sugar?

Cutting back is what quiets the urge. Sugar spikes and crashes your blood sugar, and each crash sets off cravings and false hunger. People who avoid sugar report fewer cravings. Build meals from whole, unprocessed foods. Drink your coffee black or sweeten it with stevia. And keep a homemade trail mix of fruit, nuts and a few dark chocolate chips on hand instead of candy.

Is the natural sugar in fruit bad for you?

Whole fruit is not the problem that added sugar is. Eating fruit helps you get enough fiber, vitamins and minerals, so choose whole fruit over sugar-sweetened smoothies. Many fruits are still high in natural sugar. So if you are lowering your sugar intake, lean on low-sugar choices such as strawberries, blackberries, peaches, lemons, limes, honeydew melon, oranges and grapefruit.

Related reading

• Essential Oils and Heart Health
• Using Insulin in Type 2 Diabetes
• What Is Metabolic Inflammation?
• The Problem With Refined Grains
• What Is Diabesity? How to Reverse It

References

• Healthline (2018): 11 Reasons Why Too Much Sugar Is Bad for You. Retrieved from https://www.healthline.com/nutrition/too-much-sugar#section2
• Atkins (2019): 10 Reasons Why Sugar Is Bad for Your Health. Retrieved from https://www.atkins.com/how-it-works/library/articles/10-ways-sugar-harms-your-health
• WebMD: How Does Too Much Sugar Affect Your Body? Retrieved from https://www.webmd.com/diabetes/features/how-sugar-affects-your-body
• Medical News Today (2019): 5 reasons why sugar is bad for you. Retrieved from https://www.medicalnewstoday.com/articles/324854.php

Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP
Interventional pain physician, addiction medicine specialist and obesity medicine diplomate.
Licensed in Missouri and Illinois.
Last reviewed June 18, 2026