By Franziska Spritzler, RD, CDE |

Added sugar is unhealthy when consumed in excess.

However, liquid sugar may be especially harmful.

Research shows that getting sugar in liquid form is much worse than getting it from solid food.

This is why high-sugar beverages like soda are among the worst things you can put into your body.

What Is “Liquid Sugar”?

Liquid sugar is the sugar you consume in liquid form, such as from beverages like sugar-sweetened soda.

The sugar in beverages is often highly concentrated and easy to consume in large amounts without feeling full.

Some examples of these drinks are fairly obvious, such as sodas and fruit punch. However, many other beverages are high in sugar as well.

For instance, although fruit juice is typically considered a healthier option, even varieties without added sugar can be as high in sugar and calories as sweetened drinks — sometimes even higher.

What’s more, a high intake of fruit juice may lead to the same health problems as drinking sugar-sweetened beverages (1).

Here are the calories and sugars in 12 ounces (355 ml) of some popular high-sugar beverages:

• Soda:148 calories and 34 grams of sugar (2).
• Sweetened iced tea:143 calories and 34 grams of sugar (3).
• Unsweetened orange juice:175 calories and 32 grams of sugar (4).
• Unsweetened grape juice:226 calories and 54 grams of sugar (5).
• Fruit punch:175 calories and 42 grams of sugar (6).
• Lemonade:148 calories and 37 grams of sugar (7).
• Sports beverage:118 calories and 23 grams of sugar (8).

 Bottom Line: Sweet beverages, including unsweetened fruit juice, are high in sugar calories. Frequently consuming liquid sugar calories may increase your risk of health problems.

Liquid Sugar Has Different Effects Than Sugar From Solid Food

A major problem with liquid sugar calories is that your brain doesn’t register them in the same way as the calories from solid food.

Studies show that drinking calories doesn’t elicit the same fullness signals as eating them. As a result, you don’t compensate by eating less of other foods later on (9, 10).

In one study, people who ate 450 calories in the form of jelly beans ended up eating less later.

When they drank 450 calories of soda, they ended up eating much more total calories later in the day (9).

Solid and liquid forms of fruit affect hunger levels differently as well.

People in a different study consumed a whole apple, applesauce or apple juice on six different days. Whether consumed as a meal or snack, apple juice was shown to be the least filling, while whole fruit satisfied appetite the most (10).

Bottom Line: Research shows that your body doesn’t register liquid sugar calories in the same way as sugar consumed in solid form. This can cause greater appetite and calorie intake later on.

Drinking Sugary Drinks Increases Calorie Intake and Leads to Weight Gain

Frequently consuming most types of sugar may promote excessive calorie intake and weight gain.

This may be because they contain a high amount of fructose, which is harmful when consumed in large amounts.

For example, table sugar contains 50% glucose and 50% fructose, while high fructose corn syrup contains about 45% glucose and 55% fructose.

Research shows that both affect appetite and calorie intake the same way (11).

A researcher in a recent review also pointed out that all fructose-containing sugars — including honey, agave nectar and fruit juice — have the same potential for causing weight gain (12).

What’s more, several studies link excess fructose to weight gain. A high intake seems to promote the storage of fat in the belly and around organs in the abdominal cavity, which increases disease risk (13, 14, 15, 16).

Sodas and other sweet drinks make it easy to consume large doses of sugar and fructose in a very short period of time. As stated above, these calories aren’t adequately compensated for later in the day.

However, even when calorie intake is controlled, a high intake of liquid sugars may lead to an increase in body fat.

In a 10-week study, overweight and obese people consumed 25% of calories as fructose-sweetened beverages at a calorie level that should have maintained their weight. Instead, insulin sensitivity decreased and belly fat increased (15).

In addition, a separate analysis found that fat burning and metabolic rate decreased in those who followed this fructose-rich diet for 10 weeks (16).

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Bottom Line: Several studies have linked liquid sugar calories to weight gain, which may be due to the effects of sugar and fructose on appetite and fat storage.

Liquid Sugar Raises Blood Sugar and Insulin Levels, While Harming Your Metabolic Health

In addition to promoting weight gain, liquid sugar calories can lead to elevated blood sugar levels and insulin resistance.

Several studies link a high fructose intake to a decrease in insulin sensitivity and increased risk of type 2 diabetes (17, 18, 19).

Sugary beverages seem to further increase this risk by delivering a large amount of fructose in a short amount of time.

In a detailed analysis of 11 studies including over 300,000 people, those consuming 1–2 sugar-sweetened beverages per day were 26% more likely to develop type 2 diabetes than those who drank one or fewer sweetened beverages per month (19).

In addition to insulin resistance and diabetes, frequent sugary beverage consumption has been linked to non-alcoholic fatty liver disease (NAFLD).

When you consume more fructose than your liver can store as glycogen, the extra fructose is converted into fat. Part of this fat can get stored in the liver, which may drive inflammation, insulin resistance and fatty liver disease (20, 21).

Unfortunately, insulin resistance and other health problems related to a high intake of liquid sugars often start as early as childhood and adolescence (22, 23).

Bottom Line: Consuming liquid sugar calories can lead to insulin resistance, metabolic syndrome, type 2 diabetes and fatty liver disease.

Liquid Sugar Raises Your Risk of Heart Disease

Liquid sugars also have negative effects on heart health.

When you consume a lot of fructose, triglycerides and other fat molecules are released into the bloodstream. High amounts of these fats in the blood increase heart disease risk (13, 15, 24, 25).

What’s more, this doesn’t occur exclusively in people who are insulin resistant, obese or have diabetes.

One two-week study reports that several heart health markers worsened in both overweight and normal-weight young men who drank large amounts of beverages sweetened with high fructose corn syrup (25).

Another study in healthy adults found that even small-to-moderate doses of sugar-sweetened beverages led to unhealthy changes in LDL particle size and an increase in the inflammatory marker CRP (26).

However, liquid sugars may be particularly harmful to people who are already insulin resistant or overweight.

In the 10-week study that provided 25% of calories as high-fructose beverages, overweight and obese people experienced increases in small, dense LDL particles and oxidized cholesterol. These are considered major heart disease risk factors (15).

Bottom Line: Consuming liquid sugar calories may lead to inflammation, high blood triglycerides and changes in LDL particles that increase heart disease risk.

How Much Is Too Much?

The more sugar-sweetened beverages you consume, the more problems you’re likely to cause.

In a study that provided between 0–25% of calories from sugar-sweetened beverages, those in the 25% group had a greater increase in disease risk factors than the 10% group (25).

Only the 0% group experienced no adverse effects (25).

Another study found that consuming 6.5% of calories as sugar-sweetened beverages for 3 weeks negatively affected health markers and body composition in healthy men (26).

On a 2,200-calorie diet, this would be about 143 calories, or one soda per day.

The amount of liquid sugar that can be consumed without causing health problems varies from person to person. However, limiting fruit juice to 2 ounces (59 ml) per day and completely avoiding other beverages with added sugars is your best bet.

Bottom Line: A high intake of liquid sugar is bad for your health. Limit your fruit juice consumption to 2 ounces (59 ml) per day and avoid beverages with added sugar.

What to Drink Instead

Plain water is the healthiest beverage you can drink. However, alternating plain waterwith beverages that provide a little flavor is more realistic for many people.

Here are a few healthy alternatives to sugar-sweetened beverages and fruit juice:

• Plain orsparkling water with a slice of lemon or lime.
• Iced black or green tea with lemon.
• Iced herbal tea.
• Hot or iced coffee with milk or cream.

Most of these beverages are delicious without any added sweetener.

However, if you’re transitioning from sugar-sweetened beverages, you may find it helpful to use one of these natural sweeteners.

Overall, there are many healthy and delicious alternatives to sugary beverages.