From marinara sauce to peanut butter, added sugar can be found in even the most unexpected products. Many people rely on quick, processed foods for meals and snacks. Since these products often contain added sugar, it makes up a large proportion of their daily calorie intake.
In the US, added sugars account for up to 17% of the total calorie intake of adults and up to 14% for children (1). Dietary guidelines suggest limiting calories from added sugar to less than 10% per day (2). Experts believe that sugar consumption is a major cause of obesity and many chronic diseases, such as type 2 diabetes.
Here are 11 reasons why eating too much sugar is bad for your health.
1. Can Cause Weight Gain
Rates of obesity are rising worldwide and added sugar, especially from sugar-sweetened beverages, 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.
Consuming fructose increases your hunger and desire for food more than glucose, the main type of sugar found in starchy foods (3). Additionally, excessive fructose consumption may cause resistance to leptin, an important hormone that regulates hunger and tells your body to stop eating (4).
In other words, sugary beverages don’t curb your hunger, making it easy to quickly consume a high number of liquid calories. This can lead to weight gain. Research has consistently shown that people who drink sugary beverages, such as soda and juice, weigh more than people who don’t (5).
Also, drinking a lot of sugar-sweetened beverages is linked to an increased amount of visceral fat, a kind of deep belly fat associated with conditions like diabetes and heart disease (6).
SUMMARY: Consuming too much added sugar, especially from sugary beverages, increases your risk of weight gain and can lead to visceral fat accumulation.
2. May Increase Your Risk of Heart Disease
High-sugar diets have been associated with an increased risk of many diseases, including heart disease, the number one cause of death worldwide (7). Evidence suggests that high-sugar diets can lead to obesity, inflammation and high triglyceride, blood sugar and blood pressure levels — all risk factors for heart disease (8).
Additionally, consuming too much sugar, especially from sugar-sweetened drinks, has been linked to atherosclerosis, a disease characterized by fatty, artery-clogging deposits (9). A study in over 30,000 people found that those who consumed 17–21% of calories from added sugar had a 38% greater risk of dying from heart disease, compared to those consuming only 8% of calories from added sugar (10).
Just one 16-ounce (473-ml) can of soda contains 52 grams of sugar, which equates to more than 10% of your daily calorie consumption, based on a 2,000-calorie diet (11). This means that one sugary drink a day can already put you over the recommended daily limit for added sugar.
SUMMARY: Consuming too much added sugar increases heart disease risk factors such as obesity, high blood pressure and inflammation. High-sugar diets have been linked to an increased risk of dying from heart disease.
3. Has Been Linked to Acne
A diet high in refined carbs, including sugary foods and drinks, has been associated with a higher risk of developing acne. Foods with a high glycemic index, such as processed sweets, raise your blood sugar more rapidly than foods with a lower glycemic index.
Sugary foods quickly spike blood sugar and insulin levels, causing increased androgen secretion, oil production and inflammation, all of which play a role in acne development (12). Studies have shown that low-glycemic diets are associated with a reduced acne risk, while high-glycemic diets are linked to a greater risk (13).
For example, a study in 2,300 teens demonstrated that those who frequently consumed added sugar had a 30% greater risk of developing acne (14). Also, many population studies have shown that rural communities that consume traditional, non-processed foods have almost non-existent rates of acne, compared to more urban, high-income areas (15).
These findings coincide with the theory that diets high in processed, sugar-laden foods contribute to the development of acne.
SUMMARY: High-sugar diets can increase androgen secretion, oil production and inflammation, all of which can raise your risk of developing acne.
4. Increases Your Risk of Type 2 Diabetes
The worldwide prevalence of diabetes has more than doubled over the past 30 years (16). Though there are many reasons for this, there is a clear link between excessive sugar consumption and diabetes risk.
Obesity, which is often caused by consuming too much sugar, is considered the strongest risk factor for diabetes (17). What’s more, prolonged high-sugar consumption drives resistance to insulin, a hormone produced by the pancreas that regulates blood sugar levels.
Insulin resistance causes blood sugar levels to rise and strongly increases your risk of diabetes. A population study comprising over 175 countries found that the risk of developing diabetes grew by 1.1% for every 150 calories of sugar, or about one can of soda, consumed per day (18).
SUMMARY: A high-sugar diet may lead to obesity and insulin resistance, both of which are risk factors for type 2 diabetes.
5. 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 beverages can lead to obesity, which significantly raises your risk of cancer (21). Furthermore, diets high in sugar increase inflammation in your body and may cause insulin resistance, both of which increase cancer risk (22).
A study in over 430,000 people found that added sugar consumption was positively associated with an increased risk of esophageal cancer, pleural cancer and cancer of the small intestine (23). Another study showed that women who consumed sweet buns and cookies more than three times per week were 1.42 times more likely to develop endometrial cancer than women who consumed these foods less than 0.5 times per week (24).
Research on the link between added sugar intake and cancer is ongoing, and more studies are needed to fully understand this complex relationship.
SUMMARY: Too much sugar can lead to obesity, insulin resistance and inflammation, all of which are risk factors for cancer.
6. May Increase Your Risk of Depression
While a healthy diet can help improve your mood, a diet high in added sugar and processed foods may increase your chances of developing depression. Consuming a lot of processed foods, including high-sugar products such as cakes and sugary drinks, has been associated with a higher risk of depression (25, 26).
Researchers believe that blood sugar swings, neurotransmitter dysregulation and inflammation may all be reasons for sugar’s detrimental impact on mental health (27). A study following 8,000 people for 22 years showed that men who consumed 67 grams or more of sugar per day were 23% more likely to develop depression than men who ate less than 40 grams per day (28).
Another study in over 69,000 women demonstrated that those with the highest intakes of added sugars had a significantly greater risk of depression, compared to those with the lowest intakes (29).
SUMMARY: A diet rich in added sugar and processed foods may increase depression risk in both men and women.
7. May 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. Advanced glycation end products (AGEs) are compounds formed by reactions between sugar and protein in your body. They are suspected to play a key role in skin aging (30).
Consuming a diet high in refined carbs and sugar leads to the production of AGEs, which may cause your skin to age prematurely (31). AGEs damage collagen and elastin, which are proteins that help the skin stretch and keep its youthful appearance.
When collagen and elastin become damaged, the skin loses its firmness and begins to sag. In one study, women who consumed more carbs, including added sugars, had a more wrinkled appearance than women on a high-protein, lower-carb diet (32). The researchers concluded that a lower intake of carbs was associated with better skin-aging appearance (32).
SUMMARY: Sugary foods can increase the production of AGEs, which can accelerate skin aging and wrinkle formation.
8. Can Increase Cellular Aging
Telomeres are structures found at the end of chromosomes, which are molecules that hold part or all of your genetic information. Telomeres act as protective caps, preventing chromosomes from deteriorating or fusing together.
As you grow older, telomeres naturally shorten, which causes cells to age and malfunction (33). Although the shortening of telomeres is a normal part of aging, unhealthy lifestyle choices can speed up the process.
Consuming high amounts of sugar has been shown to accelerate telomere shortening, which increases cellular aging (34). A study in 5,309 adults showed that regularly drinking sugar-sweetened beverages was associated with shorter telomere length and premature cellular aging (35).
In fact, each daily 20-ounce (591-ml) serving of sugar-sweetened soda equated to 4.6 additional years of aging, independent of other variables (35).
SUMMARY: Eating too much sugar can accelerate the shortening of telomeres, which increases cellular aging.
9. Drains Your Energy
Foods high in added sugar quickly spike blood sugar and insulin levels, leading to increased energy. However, this rise in energy levels is fleeting. Products that are loaded with sugar but lacking in protein, fiber or fat lead to a brief energy boost that’s quickly followed by a sharp drop in blood sugar, often referred to as a crash (36).
Having constant blood sugar swings can lead to major fluctuations in energy levels (37). To avoid this energy-draining cycle, choose carb sources that are low in added sugar and rich in fiber. Pairing carbs with protein or fat is another great way to keep your blood sugar and energy levels stable.
For example, eating an apple along with a small handful of almonds is an excellent snack for prolonged, consistent energy levels.
SUMMARY: High-sugar foods can negatively impact your energy levels by causing a spike in blood sugar followed by a crash.
10. Can Lead to Fatty Liver
A high intake of fructose has been consistently linked to an increased risk of fatty liver. Unlike glucose and other types of sugar, which are taken up by many cells throughout the body, fructose is almost exclusively broken down by the liver.
In the liver, fructose is converted into energy or stored as glycogen. However, the liver can only store so much glycogen before excess amounts are turned into fat. Large amounts of added sugar in the form of fructose overload your liver, leading to non-alcoholic fatty liver disease (NAFLD), a condition characterized by excessive fat buildup in the liver (38).
A study in over 5,900 adults showed that people who drank sugar-sweetened beverages daily had a 56% higher risk of developing NAFLD, compared to people who did not (39).
SUMMARY: Eating too much sugar may lead to NAFLD, a condition in which excessive fat builds up in the liver.
11. Other Health Risks
Aside from the risks listed above, sugar can harm your body in countless other ways. Research shows that too much added sugar can:
- Increase kidney disease risk: Having consistently high blood sugar levels can cause damage to the delicate blood vessels in your kidneys. This can lead to an increased risk of kidney disease (40).
- Negatively impact dental health: Eating too much sugar can cause cavities. Bacteria in your mouth feed on sugar and release acid byproducts, which cause tooth demineralization (41).
- Increase the risk of developing gout: Gout is an inflammatory condition characterized by pain in the joints. Added sugars raise uric acid levels in the blood, increasing the risk of developing or worsening gout (42).
- Accelerate cognitive decline: High-sugar diets can lead to impaired memory and have been linked to an increased risk of dementia (43).
Research on the impact of added sugar on health is ongoing, and new discoveries are constantly being made.
SUMMARY: Consuming too much sugar may worsen cognitive decline, increase gout risk, harm your kidneys and cause cavities.
How to Reduce Your Sugar Intake
Excessive added sugar has many negative health effects. Although consuming small amounts now and then is perfectly healthy, you should try to cut back on sugar whenever possible. Fortunately, simply focusing on eating whole, unprocessed foods automatically decreases the amount of sugar in your diet.
Here are some tips on how to reduce your intake of added sugars:
- 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 olive oil and vinegar in place of sweet salad dressings like honey mustard.
- Choose marinades, nut butters, ketchup and marinara sauce with zero added sugars.
- Look for cereals, granolas and granola bars with under 4 grams of sugar per serving.
- Swap your morning cereal for a bowl of rolled oats topped with nut butter and fresh berries, or an omelet made with fresh greens.
- Instead of jelly, slice fresh bananas onto your peanut butter sandwich.
- Use natural nut butters 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.
In addition, keeping a food diary is an excellent way of becoming more aware of the main sources of sugar in your diet. The best way to limit your added sugar intake is to prepare your own healthy meals at home and avoid buying foods and drinks that are high in added sugar.
SUMMARY: Focusing on preparing healthy meals and limiting your intake of foods that contain added sweeteners can help you cut back on the amount of sugar in your diet.
The Bottom Line
Eating too much added sugar can have many negative health effects. An excess of sweetened foods and beverages can lead to weight gain, blood sugar problems and an increased risk of heart disease, among other dangerous conditions.
For these reasons, added sugar should be kept to a minimum whenever possible, which 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.
Before you know it, your sugar habit will be a thing of the past.