8 Reasons Excess Sugar is Bad for Your Health

Today, excessive sugar consumption has become a public health concern.

After all, we can find large amounts of added sugars in thousands of products we consume daily. From sugary drinks to processed foods, it’s surprising how much sugar we ingest each day without even being aware of it.

However, behind its sweet taste lie health risks that deserve our attention.

In this article, we’ll explore 8 evidence-based reasons why excess added sugars are harmful to our well-being. From weight gain to the risk of chronic diseases, you'll discover how excessive sugar intake can negatively impact various aspects of our health.

Join us on this journey to understand why it’s crucial to reduce sugar consumption and make more mindful choices in our diet.

💡 With Fitia app, you can find nutritional information for thousands of products and track your intake to see if you’re exceeding the suggested sugar limits. Download it for free here.

What is Added or Free Sugar?

Before we dive into our list, we want to clarify the type of sugars we're referring to in this article: added or free sugars.

What are these sugars? Added or free sugars include sugars that are added to foods during production or by ourselves at home.

These can be found in the form of cane sugar (table sugar), high-fructose corn syrup, molasses, unrefined sugar (such as panela), syrups, or naturally occurring in foods that concentrate large amounts of sugars, like honey or fruit juices (juice = squeezed fruit or extract).

Where Can These Sugars Be Found?

We usually associate these types of sugars with products like desserts, candy, and sodas, as they do contain them.

However, there are many other products that also contain high amounts of sugars which might go unnoticed, such as flavored yogurts, energy bars, sauces like ketchup or BBQ sauce, naturally sweetened soft drinks, and more.

Now that you understand what types of sugars we’re talking about and where to find them, let’s move on to the list of 8 potential health risks from consuming them in excess.

1. It Can Lead to Weight Gain

High intake of added sugars, found in processed foods and sugary drinks, can contribute to weight gain and obesity (1,2,3,4).

This is because sugar and products high in sugars, such as candy, sodas, and more, are often very easy to consume in large quantities and contain a high caloric density.

Additionally, they are usually low in other nutrients like fiber or protein that promote satiety. As a result, it's very easy to consume a large number of calories from these products without feeling significantly full.

As you know, weight gain occurs when your calorie intake exceeds the calories you burn throughout the day. In this regard, consuming excess sugar can easily add extra calories to your day and, consequently, lead to weight gain.

In fact, various systematic reviews and meta-analyses focusing on the effects of sugary beverages have found a strong positive association between sugar consumption levels and weight gain. In other words, higher sugar intake is linked to greater weight gain across different populations (5,6,7).

2. Increases the Risk of Type 2 Diabetes

Similarly, there is extensive and compelling scientific evidence indicating that excessive sugar intake is associated with an increased risk of developing type 2 diabetes mellitus and other related metabolic disorders, such as metabolic syndrome (7,8).

One of the main reasons for this effect is that long-term excess sugar consumption leads to insulin resistance.

When we consume large amounts of sugar, the body becomes less sensitive to the action of insulin (the hormone responsible for regulating blood sugar levels) (9).

This triggers a condition known as insulin resistance. As a result, your pancreas needs to produce more insulin to keep blood sugar levels under control, which eventually damages pancreatic function. At some point, the amount of insulin produced will no longer be sufficient to maintain blood sugar levels (9).

This leads to persistently high blood glucose levels and opens the door to type 2 diabetes mellitus (9,10).

Additionally, as seen in point 1, excess sugar is also related to overweight and obesity, both of which are risk factors for type 2 diabetes mellitus.

This is because excess body fat can interfere with how the body uses insulin and increase insulin resistance.

Moreover, excessive sugar consumption can trigger inflammatory processes and oxidative stress in the body. These factors can damage the pancreatic cells responsible for producing insulin and contribute to the development of type 2 diabetes.

3. Increases the Risk of Heart Disease

Another risk of excessive sugar consumption is that it can impact your heart health and overall cardiovascular system.

Evidence has confirmed that consuming too much sugar, especially through sugary drinks and ultra-processed foods, increases the likelihood of developing heart disease (2,11,12).

One of the most significant factors is the weight gain associated with high sugar intake:

Excessive sugar can contribute to weight gain and obesity, which in turn raises the risk of heart disease. Obesity is linked to high levels of LDL cholesterol (the "bad" cholesterol), elevated triglycerides, and high blood pressure—all factors that can harm your heart (12,13).

In fact, high triglyceride levels increase the risk of plaque buildup in the arteries, which can block blood flow to the heart and lead to a heart attack.

4. Can Increase the Risk of Fatty Liver Disease

When you consume sugars in amounts exceeding what your body needs, they are initially stored as glycogen. However, our glycogen reserves have a limit.

Once these reserves are full and there is still excess sugar available, it begins to be stored as fat.

The liver plays a crucial role in this process, especially when it comes to processing fructose.

As mentioned earlier in the article, one of the most common forms of sugar found in processed products (especially sodas) is high-fructose corn syrup.

This type of sugar is almost entirely processed in the liver, so excess sugars of this kind can lead to fat accumulation in the liver (hepatic steatosis), resulting in fatty liver disease.

In fact, evidence shows that these types of sugars are strongly associated with an increased risk of non-alcoholic fatty liver disease (14,15).

For example, one study found that those with higher consumption of sugary sodas (more than one serving per day) had a 61% higher risk of developing fatty liver compared to those who did not consume sugary sodas (16).

Fatty liver can cause various health problems. It can interfere with the liver's ability to function properly and may lead to more severe liver or even cardiovascular diseases.

Remember that taking care of your liver is essential for your overall health, as the liver plays a vital role in metabolism and detoxification of your body.

5. Deteriorates Oral Health

This point might not surprise you: excessive sugar consumption can negatively impact your oral health—even if you maintain good oral hygiene (17,18,19).

When you consume large amounts of sugar, especially through sugary foods and drinks, it creates an environment conducive to the growth of harmful bacteria in your mouth (affecting your oral microbiota).

These bacteria feed on the sugars in your mouth and produce acids as a byproduct. These acids can damage the tooth enamel, which is the outermost protective layer of your teeth. Over time, this can lead to the formation of dental cavities (17,18,19).

Additionally, excessive sugar intake can contribute to the development of periodontitis or gum disease. Bacteria in your mouth form a sticky film called dental plaque on your teeth and gums. Sugar provides an ideal substrate for these bacteria to grow and multiply, which can lead to inflammation of the gums or periodontitis (20).

In fact, untreated periodontitis (which might not cause significant discomfort) can progress and affect the tissues and bones that support your teeth, potentially leading to tooth loss.

Moreover, evidence shows that there is an interrelation between chronic gum inflammation due to excess sugar and an increased risk of type 2 diabetes, both related to excessive sugar intake (21,22).

While good oral hygiene is a key factor in maintaining oral health, remember that your diet also has a significant impact.

6. Adds Calories Without Nutritional Value

If your sugar intake is very high, it’s likely that your consumption of ultra-processed foods is also high.

These types of foods, which are rich in added sugars, often lack essential nutrients like proteins, healthy fats, vitamins, minerals, fiber, and antioxidants.

They might provide quick energy but do not significantly contribute to a balanced and healthy diet.

So, if you prioritize foods that are high in added sugars and low in important nutrients, you’re likely to fall short on the nutrients you really need, which could lead to deficiencies and various health issues.

At this point, it’s worth noting that maintaining a balanced diet that meets your nutritional needs doesn’t mean you can’t enjoy less nutritious foods like cakes or candy.

However, it does mean that less nutritious foods should play a secondary role in your diet; they shouldn’t make up the majority of what you consume daily.

👉 You might be interested in: 7 Benefits of Protein Backed by Science

7. Can Have a Negative Impact on Mental Health

Some studies suggest that a high-sugar diet may be linked to an increased risk of depression and mood disorders (23,24,25).

While further research is needed, it is currently believed that excessive sugar consumption may affect the production of neurotransmitters, particularly serotonin, which is associated with feelings of happiness and well-being.

8. Can Worsen Acne and Deteriorate Skin Health

Consuming excessive amounts of sugar can negatively impact your skin health and contribute to the development of acne.

When you consume large quantities of sugar frequently, especially refined sugars and processed foods high in sugar, it can cause hormonal changes in your body that may promote acne (26,27).

For example, consistently high insulin levels (as seen with insulin resistance) can stimulate the release of hormones called androgens, which can increase oil production in the skin. Excess oil can clog pores and contribute to acne development and interfere with its treatment (28,29).

Additionally, a range of inflammatory responses can be triggered in the body, including inflammation in the skin. Chronic inflammation can worsen existing acne and hinder the healing of skin lesions (26,28).

Moreover, excessive sugar consumption can compromise overall skin health by damaging collagen and elastin, two key proteins that keep the skin firm and elastic.

Sugar can contribute to the process of glycation, which is the non-enzymatic binding of sugar molecules to proteins like collagen. This can lead to the formation of advanced glycation end products (AGEs), which can damage the structure and function of the skin (30,31).

So, How Much Added or Free Sugar Can You Consume?

The recommendation is to reduce the intake of added or free sugars to less than 10% of your total calorie intake, and ideally, reduce it to less than 5%.

This means that in a 2,000 kcal diet, you should not exceed 25 grams of free sugar per day, which is about 5 to 6 teaspoons.

This recommendation varies depending on your total energy requirements. If you don’t yet know your requirements, you can calculate them for free and automatically with Fitia app. Download it for free here.

However, keep in mind that the official recommendation says "less than," meaning it could ideally be zero, and it’s better if it is.

In reality, the goal is to minimize the consumption of these types of sugars as much as possible.

Ideally, you would get used to the natural taste of foods and not need any sweeteners, but we know this is not the easiest to implement right from the start.

So, if you’re just starting to reduce your sugar intake, we recommend taking gradual steps:

• Start by reducing the number of teaspoons you add to your beverages or choose natural sweeteners like stevia or monk fruit as replacements.
• Opt for sugar-free versions of products like yogurts, sodas, cereals, sauces, etc.
• If you want something sweet, choose fruits or foods that naturally have a sweet taste.