How Does High Sugar Diet Affect the Digestive System?

If you love consuming a high sugar diet, then you must explore this article because your habit may jeopardize your health.

We all know that a diet high in sugars can be detrimental to your health. Heart disease, diabetes, high cholesterol, elevated blood pressure … they can all be linked to a high sugar diet. But eating too much sugar can also play havoc with your digestive system.

How Does High Sugar Diet Affect the Digestive System?
What effect, exactly, does sugar have on our body as a whole? Shutterstock Images

What is Sugar?

When you think of sugar, you probably think of white granules in a sugar bowl. But it’s a lot more complex than that.

Sugar comes in many forms depending on its source and degree of processing. There’s raw sugar, brown sugar, fruit sugar, corn sugar, milk sugar, beet sugar.

Then there are sugar alcohols, and the components of sugar – monosaccharides, disaccharides, and polysaccharides.

  • Natural Sugars: Found in varying amounts in fruits, vegetables, dairy and grains.
  • Refined Sugars (Table Sugar, Sucrose): The main type of refined sugar, usually in the form of crystals, syrups or powders. They are no longer ‘natural’ because they have been altered or processed in some way.

How Much Sugar SHOULD You Be Eating?

Sugar intake is typically high in the Western diet. High sugar consumption has been linked to many chronic diseases, including obesity, type II diabetes, cardiovascular disease, certain cancers, fatty liver disease and more.

The American Heart Association (AHA) recommends a maximum amount of added sugar[1] as:

  • Men: 150 calories per day (37.5 grams or 9 teaspoons)
  • Women: 100 calories per day (25 grams or 6 teaspoons)

In the UK, the NHS recommends a sugar intake of less than 5% of the energy you get from food and drink each day, which equates to 30g of sugar a day for those aged 11 and over. However, research suggests that added sugars currently 10% of the calories in the average American’s diet[2].

Excess Sugar and Your Body

Excess Sugar

The pancreas produces insulin which converts glucose into energy, but when the body is resistant to its effects, then it can lead to the high glucose level.

When we eat foods containing added sugar, both glucose and fructose are released into the bloodstream. The pancreas then releases insulin, a hormone which helps to “unlock” the body’s cells to allow glucose to be used by the cells for energy.

Insulin works to regulate the flow of glucose to and from the blood. It also allows the muscles to get the glucose they need from the blood supply.


*All individuals are unique. Your results can and will vary.

Insulin resistance occurs when the cells in muscles, fat and the liver do not respond properly to insulin and thus cannot easily absorb glucose from the bloodstream.

As a result, the body needs higher levels of insulin to help glucose enter cells. This, in turn, causes the pancreas to produce more and more insulin. But when this is no longer possible, excess sugar builds up in the bloodstream. This leads to type II diabetes or prediabetes.

There is also evidence that excess sugar can affect the balance of your gut flora[3], leading to conditions like SIBO or yeast overgrowth.

Related: Sugar And Weight Loss – Losing Weight Faster By Curbing Hidden Sugar Intake

How Excess Sugar Affects Your Digestion?

  • Diarrhea: Studies have shown a link between diarrhea and the poor digestion of certain sugars[4]. People with celiac disease, Crohn’s disease and chronic diarrhea produce an abnormally high amount of mucous in the intestines, which hinders digestion prevents the absorption of these starches and disaccharides.
  • Gastroparesis: In people with chronically high blood sugar, gastroparesis may be caused by damage to the vagus nerve[5].

This means that food entering the stomach is not mechanically broken down, and ends up sitting in the stomach for a longer period of time. This causes gas, bloating, indigestion and heartburn.


Overconsumption of Sugar causes a Gastric problem. Shutterstock Images

  • Gas: Excess sugar that cannot be broken down and absorbed by the body will be left to sit in the bowels, where it ferments. This sugar moves more slowly through the large intestine, feeding bad bacteria and yeast, and causing a build-up of gas. This gas can cause cramping, spasms and pain.
  • Sugar Intolerances: Lactose is the sugar found in milk. Lactose intolerance occurs when your body doesn’t produce the enzyme required to break down lactose, resulting in gas, bloating and other digestive discomforts. In a similar way, high fructose corn syrup can inhibit digestion because the body can’t break it down either. The fructose stays in the intestines, causing gastrointestinal bloating and discomfort.
  • Bloating: Although absorbing water is the main job of the large intestine, sugar can draw water into the large intestine or at least prevent it from being absorbed properly. This can lead to bloating or heaviness in the gut.
  • Liver damage: Digestion is stimulated by the liver. Fructose can only be processed by the liver, so all the fructose ingested is sent to the liver at once, overloading it and causing potential damage, which in turn impairs digestion.
  • Metabolic Dysfunction: Fructose fails to stimulate insulin, which in turn fails to suppress the ‘hunger hormone’ ghrelin. As a result, the satiety hormone leptin isn’t stimulated either, which causes you to eat more.

This leads to weight gain, abdominal obesity, decreased HDL and increased LDL, elevated blood sugar, elevated triglycerides, and high blood pressure.

Cut the Sugar With these Alternatives

Cut The Sugar

You can control your sugar by using natural sweetener like Stevia. Shutterstock Images

Reducing sugar intake doesn’t have to mean going without sweet things altogether.

Here are some alternatives to the big, bad, sweet stuff.

  • Erythritol: Erythritol is 60-70 percent as sweet as table sugar – and yet it’s almost calorie-free. It doesn’t affect blood sugar levels, doesn’t cause tooth decay, and doesn’t contribute to weight gain.
  • Xylitol: The alcohol form of xylose, xylitol has 40% fewer calories than sugar and 75% less carbohydrates.
  • Stevia: Stevia is a natural sweetener derived from the leaves of the stevia plant. The steviol glycosides in stevia are 250-300 times sweeter than table sugar but contain no calories.

Read NextTips For Testing Your Blood Sugar At Home


*All individuals are unique. Your results can and will vary.

Give your digestive system a break by cutting your sugar intake. The benefits of reducing the amount of sugar in your diet far outweigh the enjoyment of sugar itself. And if you can’t ignore your sweet tooth, choose an alternative!

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