What Happens to Your Body When You Stop Eating Sugar, According to Nutrition Experts

When it comes to nutrition, it's easy to focus on the foods you should eat more of. Think fruits, vegetables, lean proteins, healthy fats, and whole grains. However, it's just as important to consider the things you should eat less of, like added sugar. Added sugars can have a place in a healthy diet; the key is to enjoy them in moderation and mindfully. This approach will benefit short-term and long-term health, especially if you already eat added sugars often. How, exactly? We asked dietitians to share what happens when you limit or cut out added sugars, plus tips for doing so.

Natural Sugar vs. Added Sugar

On a molecular level, sugar is sugar, whether it's natural or added. But as with many aspects of nutrition, it's worth looking at the bigger picture—or in this case, the specific source of sugar.

"The difference lies in the typical amount of sugar per serving as well as the additional nutrients the food provides," says Destinee Uffer, RDN, LD. Foods with natural sugars (like fruit) do contain sugar, but they also provide beneficial micronutrients, such as vitamins, minerals, fiber, and even a bit of hydration. "These foods offer substantial nutrition, along with serving as a quick source of energy for the body."

In contrast, foods with added sugar contain sugar and often not much else. They may also contain fat (in the form of saturated or "bad" fat) and a significant amount of calories per serving. Examples include sweetened lattes, packaged baked goods, and some bottled salad dressings. "These foods are considered more energy-dense, meaning they provide more calories in a smaller amount of food while offering less nutritional value," says Uffer.

"Put simply, natural sugar options offer more nutritional value for the calories consumed," notes Uffer. So, when experts discuss the benefits of reducing sugar, it's important to know they're referring to the added type.

What Happens Right After You Reduce Added Sugar

When you first reduce your intake of added sugars, you might experience lower energy levels, fatigue, increased cravings for foods high in sugar, and irritability, says Uffer. You might also have headaches, notes Isabel Balady, RDN, CDN. "This can happen as your body adjusts to having less blood sugar spikes and less serotonin from carbohydrate intake," Uffer says.

The exact symptoms also vary by person, as it depends on how much sugar you usually eat, your overall diet quality, stress levels, and whether your decrease in sugar intake is gradual or abrupt, says Uffer. For most people, these symptoms will stop after a few days to a few weeks.

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What Happens When You Eat Less Added Sugar Over Time

If you continue limiting your intake of added sugar, you'll experience these long-term benefits.

More Stable Energy

As mentioned, added sugar is often absorbed rapidly, leading to blood sugar spikes. "In response, the body releases a large amount of insulin to help reduce blood sugar. The rapid spike in blood sugar, followed by a quick drop, can leave [you] feeling fatigued, shaky, and craving more sugar shortly after eating," says Balady. "Over time, these blood sugar fluctuations can contribute to inconsistent energy levels and mood throughout the day," she notes.

But when you reduce your intake of added sugar, you're likely to experience more stable energy throughout the day and fewer afternoon crashes, says Balady.

Improved Sleep

The blood sugar fluctuations associated with high added sugar intake can interfere with your body's circadian rhythm, or sleep-wake cycle, says Balady. In fact, research has found that poor sleep quality is linked to high added sugar intake. "Reducing added sugars can help balance blood sugar levels to support steadier energy throughout the day and more restorative sleep at night," she says.

Better Mood

Though you might feel irritable at first, consistently reducing added sugar can support your long-term mental wellness. Why? "Sugar may influence mood by promoting inflammation in the body and disrupting the gut's microbiome, the community of beneficial bacteria that plays a role in mental health," says Natalie Allen, RD. While research is still evolving, studies show associations between high added sugar intake and an increased risk of depression and anxiety, notes Allen.

Improved Digestion

Added sugar can weaken the gut's protective lining, disrupt the balance of good vs. bad intestinal bacteria, and increase gut inflammation, says Allen. A high-sugar diet is also linked to a greater risk of inflammatory bowel conditions like Crohn's disease and ulcerative colitis, partly because sugary foods tend to crowd out fiber-rich foods that nourish healthy gut bacteria, Allen says. However, these issues may be prevented by scaling back on added sugars.

Less Unwanted Weight Gain

"Foods with added sugar tend to be high in calories but low in protein and fiber, meaning they don't keep you full, making it easy to overeat," Allen says. This can lead to unwanted weight gain, potentially increasing the risk of chronic disease over time. But when you eat less added sugars (along with a balanced diet), you're more likely to experience better weight management.

Lower Heart Disease Risk

"People who get more than 25 percent of their daily calories from added sugar are up to three times more likely to develop heart problems," says Allen. The risk is especially significant with sugar-sweetened beverages and juices, she notes. Therefore, consuming less added sugar can protect your heart, especially over time. 

Lower Type 2 Diabetes Risk

As mentioned, frequent consumption of large amounts of added sugar can cause constant blood sugar spikes. But if you reduce your intake, the influx of sugar entering the bloodstream becomes more manageable, says Uffer. Over time, this can help lower the risk of prediabetes and type 2 diabetes, especially when paired with a balanced diet and lifestyle.

Less Inflammation

Consuming less added sugars helps manage inflammation. "A high intake of added sugar and repeated spikes in blood sugar put stress on numerous areas of the body, including the pancreas, cardiovascular system, and the liver, all of which can contribute to inflammatory processes," says Uffer. In contrast, eating fewer added sugars can reduce inflammation, thereby supporting overall health.

Tips to Help You Eat Less Added Sugar

"It's important to note that you can reduce added sugar intake and maintain a balanced diet while continuing to enjoy the foods you like," says Uffer. Balady thinks similarly, noting that the goal is to create a more balanced, sustainable eating pattern, not to eliminate all enjoyable foods.

Consider these healthy, practical ways to help you curb added sugars.

• Read nutrition labels: Added sugars often appear in unexpected foods. Examples include sauces, dressings, condiments, and flavored yogurts, says Balady.
• Know the names of different sugars: Added sugar goes by many names, such as corn syrup, dextrose, and maltose, says Allen.
• Limit sugary drinks: "Swap sugary drinks for sparkling water, infused water, or unsweetened tea or coffee," says Allen. This single change can make a big difference, she says.
• Consider the bigger picture: "If breakfast is on the sweeter side, simply scale back added sugar at lunch and dinner," says Allen. The whole day, as well as the long-term pattern, is what matters most, she says. Likewise, Balady recommends focusing on nourishing foods vs. restriction, which often naturally leads to reduced added sugar intake.