An apple contains sugar.

So does a candy bar.

A glass of milk contains sugar.

So does a can of soda.

That can lead to a perfectly reasonable question:

If they all contain sugar, does the body really know the difference?

The answer is both yes and no.

Once sugars are digested and absorbed, the body deals with individual sugar molecules through the same basic metabolic pathways. Glucose is glucose whether some of it ultimately came from an apple, a cookie, or a slice of bread.

But that doesn’t mean those foods have the same effect on the body.

Because we don’t eat glucose molecules in isolation.

We eat food.

And everything that comes along with that food matters.

What Do We Mean by Natural Sugar?

Naturally occurring sugars are sugars that are already present in a food rather than being added during preparation or manufacturing.

Fruit contains naturally occurring sugars.

Milk contains lactose, a naturally occurring sugar.

Some vegetables contain sugars as well.

But when you eat a piece of whole fruit, you aren’t eating sugar alone.

You’re also eating varying amounts of fiber, water, vitamins, minerals, and other compounds.

Milk provides protein, calcium, phosphorus, and other nutrients along with its naturally occurring lactose.

That surrounding nutritional package is important.

What Is Added Sugar?

Added sugars are sugars added to foods or beverages during manufacturing, cooking, or preparation.

Table sugar is an obvious example.

But added sugar has many names and appears in many places.

It can be found in soda, candy, cookies, cakes, sweetened cereals, flavored yogurts, coffee drinks, sauces, condiments, granola bars, and many packaged foods.

Honey, syrups, and other sweeteners may sound more natural, but when they’re added to foods, they still contribute added sugars.

This doesn’t make a food poisonous.

It simply helps explain where some of the sugar in our diets comes from.

Your Body Doesn’t Read the Package

Your digestive system doesn’t look at a food and decide:

“This is an apple, so this sugar is healthy.”

Or:

“This is a cookie, so this sugar is bad.”

The body responds to what actually arrives.

How much carbohydrate is present?

What kinds?

How quickly is it digested?

Is there fiber?

Is there protein or fat in the meal?

How much was eaten?

What else was eaten with it?

How active is the person?

How effectively is their body responding to insulin?

All of those things can influence what happens after eating.

That’s why reducing nutrition to sugar equals bad doesn’t tell us very much.

Consider an Orange

Take a whole orange.

It contains sugar.

It also contains water and fiber, and you have to chew it.

Now compare that with orange juice.

Several oranges may be used to produce one glass of juice, much of the fiber from the whole fruit is absent, and it’s easy to drink the juice quickly.

Both came from oranges.

Both contain naturally occurring sugars.

But they aren’t necessarily handled in exactly the same way because the form of the food has changed.

That doesn’t mean orange juice is forbidden.

It means form matters.

Fiber Changes the Conversation

Fiber is one of the reasons whole foods containing sugar can behave differently from highly refined foods or sugary beverages.

Fiber isn’t completely broken down and absorbed in the same way as digestible carbohydrates.

Among its many roles, fiber can slow digestion and influence how quickly glucose enters the bloodstream.

Fiber can also contribute to fullness and has important roles in bowel and cardiovascular health.

This is why looking only at grams of sugar can miss part of the story.

Two foods can contain sugar while providing very different amounts of fiber and other nutrients.

Liquid Sugar Is Easy to Consume

Sugar-sweetened beverages deserve particular attention because drinking sugar is different from sitting down and eating a meal.

A large sweetened drink can contain a considerable amount of added sugar and can be consumed quickly.

It may also be less filling than solid food providing a similar amount of energy.

That doesn’t mean having a soda occasionally determines someone’s health.

It means that when sugar-sweetened beverages become a frequent part of someone’s overall eating pattern, the amount of added sugar can accumulate without being particularly obvious.

Patterns matter more than one drink.

“Natural” Doesn’t Automatically Mean Better

Food marketing can make this especially confusing.

A package may advertise:

Made with honey.

Sweetened with agave.

No refined sugar.

All natural.

Those phrases can make a product sound metabolically different from something made with ordinary table sugar.

But the body doesn’t assign moral value to a sweetener because it came from a plant or has a more appealing name.

Honey and syrups still contain sugars.

That doesn’t mean they should never be eaten.

It simply means “natural” isn’t the same thing as “doesn’t count.”

And “Processed” Doesn’t Automatically Mean Bad

The same caution applies in the other direction.

Almost everything we eat has been processed in some way.

Frozen vegetables are processed.

Canned beans are processed.

Yogurt is processed.

Bread is processed.

The word itself doesn’t tell us whether a food is nutritious or appropriate for a particular person.

Healthcare conversations become much more useful when we stop sorting every food into two boxes labeled good and bad.

Aging Can Change the Context

As we get older, nutrition can become more complicated—not less.

One person may be trying to manage elevated blood glucose.

Another may be struggling to maintain weight.

Someone else may have difficulty chewing or swallowing.

A person recovering from surgery may have very little appetite.

An older adult living alone may depend on foods that are inexpensive, convenient, easy to prepare, or simply appealing enough that they will actually eat them.

That matters.

Telling someone to remove foods from their diet without understanding the rest of their situation can create problems of its own.

Sometimes the more important question isn’t:

“Does this contain sugar?”

It is:

“What does this person need right now?”

One Food Doesn’t Tell Us How Someone Eats

Seeing someone eat a doughnut tells us almost nothing about their overall health.

We don’t know what they ate yesterday.

We don’t know their laboratory values.

We don’t know their medical history.

We don’t know whether they’re losing weight.

We don’t know whether they have diabetes.

We don’t know whether that doughnut is an occasional pleasure or something they eat every morning.

And frankly, we don’t know whether they simply decided they wanted a doughnut.

Food choices exist within a much larger life.

Understanding Instead of Judging

Naturally occurring and added sugars aren’t identical from a nutritional perspective because the foods containing them can be very different.

But the lesson isn’t:

Fruit good. Candy bad.

The more useful lesson is to understand what else comes with the food, how much and how often we consume it, and what is happening in our individual bodies.

Sometimes a piece of fruit makes sense.

Sometimes dessert makes sense.

Sometimes someone’s medical condition makes blood glucose particularly important.

And sometimes enjoying the dessert is important too.

Knowing the difference between natural and added sugars gives us information.

It doesn’t give us permission to judge someone else’s plate.

Next, we’ll look at something that becomes especially important over time:

Why can the body begin handling glucose differently as we age—even when we haven’t dramatically changed the way we eat?