This Is What Happens to Your Body When You Eat Sugar

Your body needs fuel and a treat won't hurt, but too much sugar can have downsides.

Most of us enjoy the way sugar makes food taste and us feel. It adds flavor to a wide variety of foods and drinks: not just desserts and candies but also sodas, pasta sauces, and any number of prepared foods. It's so enjoyable that most men take in about 19 teaspoons of added sugar daily, and women eat or drink about 15.

There are two types of sugar: natural and added. Natural sugars, as the name implies, occur naturally in foods, such as fruit, which has fructose, and milk, which has lactose. Added sugars are combined with other ingredients in prepared foods and come from high fructose corn syrup, table sugar, and many other sugar-containing ingredients.

Your body needs glucose, a form of sugar, to survive. But you don't need to eat glucose or other sugars because your body makes it from the food you eat.

Here's what happens to your body when you eat too much added sugar.

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Why Does Your Body Need Sugar?

Every cell in your body uses glucose for energy. In fact, that's what your body makes when it breaks down proteins, fats, and carbohydrates. Your body uses the glucose it makes from food to fuel your brain and your organs.

What Happens When You Eat Sugar?

When you eat sugar, your body breaks it down via saliva, even before it leaves your mouth. It then travels through your digestive tract, where it's absorbed into your bloodstream as glucose. This raises your blood sugar level, causing your pancreas to release insulin. Insulin is a hormone that tells your cells to absorb glucose.

Sugars tend to be absorbed into your bloodstream quickly, causing spikes in your insulin levels which can be problematic over time. Your body stores the extra glucose in your liver and muscle tissues until you need it. It's also converted to fatty tissue.

How Much Sugar Should You Eat?

The Dietary Guidelines for Americans—suggestions to help you meet your nutrient needs, promote health, and avoid preventable chronic conditions—call for no added sugars for children younger than 2 and less than 50 grams, or 10 percent of daily calories, for adults eating 2,000 calories a day.

To put 50 grams in perspective, here are some examples of how much added sugar some foods contain:

  • One piece of chocolate cake that you'd find in a grocery store bakery contains about 55 grams.
  • A 16-ounce glass of apple juice contains 48 grams.
  • A cup of Bush's sweet heat-baked beans has 26 grams.
  • Fage honey split cup yogurt has 25 grams.

The guidelines for added sugar are recommended for the maximum you should eat or drink per day, not a recommendation that you eat that much (or even any) added sugar. (There aren't any guidelines for how much natural sugar you should get.)

Most Americans' primary sources of added sugars are sugar-sweetened beverages, baked goods, desserts, and sweets.

There are different names for added sugar, which comes from other sugar-containing ingredients. Types of added sugars include:

  • Cane juice
  • Concentrated fruit or vegetable juice
  • Dextrose
  • Fructose
  • Glucose
  • High fructose corn syrup
  • Honey
  • Malt syrup
  • Maple syrup
  • Molasses
  • Sucrose
  • Sugar
  • Sugar cane

Downsides of Too Much Sugar

Eating too much added sugar regularly is also associated with unpleasant side effects, such as noticeable changes in your thinking, energy, and stress levels. Here are a few to consider.

It Can Impact Brain Function

Too much added sugar changes how your brain functions and has been linked to cognitive decline and degenerative disorders such as Alzheimer's disease and dementia.

A 2019 study of more than 1,200 Malaysian adults older than 60 found excessive sugar consumption was associated with poorer cognitive function. However, more research is needed to understand why that is.

A 2015 review of the literature also concluded that eating diets high in saturated fat and sugar led to a range of memory and cognitive impairments regardless of age.

The authors suggested that this may be due to the inflammatory effects of fat and sugar on the central nervous system and hippocampus. That's the brain region that, among other things, controls certain types of memory and our response to hunger cues.

It Can Lead to Increased Sugar Cravings

Eating large amounts of sugar revs up the brain's reward and appetite center. Over time that can interfere with feelings of fullness and satisfaction so that you are less content with the same amount of sugar.

That, in turn, could lead to an almost addictive pattern of sugar cravings and overeating, leading to becoming overweight or developing obesity.

Your Skin Might Age Faster

Consuming a lot of added sugar can hinder collagen repair. Collagen is a protein that keeps skin looking plump, and the lack of it leads to thinner skin and skin aging. A steady diet of sugary treats can also result in reduced elasticity, poor wound healing, and premature wrinkles because of the way the body breaks down excessive sugar.

One strategy to protect your skin is to indulge your sweet tooth with fruit instead. Fruit also contains antioxidants, which protect your body from the damaging inflammation that leads to aging and the development of chronic diseases.

The Dietary Guidelines for Americans 2020-2025 recommend two cups of fruit daily.

It Could Lead to a Blood Sugar Crash

Refined carbs in foods and drinks like sodas, cookies, cakes, or pies can quickly cause a rise in glucose in the bloodstream, so you might feel extra energized—for a while. But this short-term fix can make you more sluggish later (when you eventually crash).

Instead, opt for protein-rich snacks between meals, such as Greek yogurt with fresh berries or fresh veggies and hummus. Protein helps stabilize blood sugar and keeps you going longer.

You Might Not Use All The Calories

While added sugar can provide your body with energy in the form of calories, it offers little nutritional value.

Sugary products, especially beverages, don't leave you feeling full, and sugar spikes and crashes from them can make you hungrier later. Increased hunger can lead you to eat more than you need, causing a pattern of overeating that can lead to weight gain.

It Can Increase the Risk of Chronic Disease

Too much added sugar can accelerate the usual oxidation process in our cells. Put simply, it creates oxidative stress in our body that can damage proteins, tissues, and organs. That can increase our risk of health conditions, including cancer, heart disease, diabetes, and metabolic disorders.

Too much added sugar has also been linked to other conditions, including:

  • Cardiovascular disease
  • Diabetes
  • Non-alcoholic fatty liver disease
  • Cognitive decline
  • Some cancers

It Can Increase Stress Levels

While research shows that sweets can lower levels of the stress hormone cortisol in the short term, they may cause problems in the long term. A small 2015 study found that some people under stress may be more vulnerable to becoming hooked on sweets because it releases soothing brain chemicals.

However, the effect is temporary, and the stressed feeling can return, only a little worse than before, leading to more sugar consumption.

A 2019 review of more than 300 studies also highlighted the relationship between sugar consumption and self-medication for states like stress, anxiety, and depression. In some people, this can lead to self-medication with more sweets.

Here are some stress-relieving foods you could try instead:

  • Leafy green vegetables
  • Avocado
  • Beets
  • Dark chocolate
  • Turkey
  • Green tea

A Quick Review

A few things can happen in your body when you eat sugar. Consuming it in moderation will likely have little impact, and there's nothing wrong with enjoying a sweet treat when you feel like it.

But consuming too much added sugar over a long period can have some downsides, including blood sugar crashes, faster aging, and an increased risk of obesity and other chronic conditions such as heart disease, diabetes, or cognitive decline.

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