Is Sugar Bad For You?

It's been demonized and singled out as the cause of the obesity epidemic. But is sugar bad for you? Are all sugars equal? Here's what science has to say.

Sugar is not toxic. And, it’s not the primary cause of obesity.

Those are the first two things you need to know when considering if sugar is bad. After all, your body is perfectly designed to metabolize sugar. When you eat carbohydrates (any carbohydrates, vegetables included) your body eventually breaks them down into glucose (AKA sugar).

So, the idea that sugar is bad when your body is designed to use it and convert it into energy just doesn’t make sense.

Now, that’s not to say that too much sugar can’t be a problem. It can, but understanding your limits can make your diet a lot less stressful and a lot more delicious. Let’s dig in.

Is Sugar The Cause of Obesity and Diabetes?

If you’re going to stand up for sugar for anything (because, again, it has some downsides, which we’ll discuss), it’s the belief that sugar is the cause of diseases like obesity and diabetes.

person getting finger pricked

Yes, sugar can play an indirect role in both. But, data and research don’t align to suggest that both diseases are driven by sugar.

Over the last 40 years, our sugar consumption has shifted from 20.8 teaspoons of sugar per day in the 1970s to about 23 teaspoons of sugar per day. Both numbers are too high, but the ~2.2 teaspoons increase is only about 32 added extra calories. Again, too much sugar, but the increase in sugar is not what’s driving obesity.

After all, according to USDA data, calorie consumption has increased by anywhere from 600 to 700 calories over the same time period. For reference, the consumption of fats and oils jumped from 52 pounds per year (per person) in the 1970s to 82 pounds per year more recently.

The problem with obesity is too many calories. And that is a complicated problem that includes many factors such as food availability, hyper-palatable foods (think fat, salty, and sweet combined), psychological factors, social factors, and genetics.

Can sugar potentially make you desire to eat more? Yes. But, as you’ll find out, the poison is in the dose and the source. It’s not one or the other.

The same goes for diabetes. Many people believe that sugar causes diabetes. In reality, it’s excess body fat that triggers the disease. If you have too much body fat, then it creates insulin resistance, which means your body’s natural glucose control breaks and you start storing and processing sugar differently. That’s what leads to prediabetes and, ultimately, diabetes.

So Why Do People Think Sugar is Toxic?

The short answer: because it makes for a compelling narrative in a book or documentary.

Listen, sugar has its downsides, and limiting sugar is a good thing. But, the idea that you need to avoid all sugar isn’t supported by science.

If sugar is bad and “toxic,” then what should you think about fruit?

Before you buy into the easy-to-sell idea that sugar is the root of all evil, you might want to consider that over the last 50 years, different ingredients or macronutrients tend to be blamed for all health issues.

Despite science that suggests one food is not the reason for all health shortcomings, many are convinced that carbs and sugar are inherently bad.

Sugar’s real “toxicity” level is something like 6 pounds per day (test in rats). That’s not happening to even the biggest sweet tooth.

When people talk about toxicity, they usually are referring to the addictive nature of sugar. The anti-sugar crowd likes to compare it with addictive drugs.

But, if you were to eat a spoonful of sugar (cue Mary Poppins), how much would you want to shovel down a second, third, or fourth spoonful?

The answer is most people wouldn’t because sugar alone does not drive palatability. There are many factors, which include:

  • A combination of sweet, starch, and fat
  • Mouth-feel
  • Salt
  • Consistency

Even research suggests that sugar-alone isn’t driving food obsession. A comprehensive review found that sugar was not addictive, but that high-fat savory and high-fat sweet foods are much more likely to be overeaten than mostly sugary sweet foods.

Which Sugars Are Better and Healthier?

Sugar is far more than just the white stuff you spoon into your coffee. (That’s sucrose.)

In biochemistry, sugar is either a monosaccharide or a disaccharide (“saccharides” being another name for “carbohydrates”).

  • A monosaccharide is a simple sugar.
  • A disaccharide is a sugar composed of two simple sugars.
  • An oligosaccharide is composed of two to ten simple sugars.
  • A polysaccharide is composed of two or more simple sugars (300 to 1,000 glucose molecules in starch).

In short, all carbohydrates are composed of single sugars. If we go back to the example of sucrose, or table sugar, that’s actually a disaccharide of the simple sugars glucose and fructose.

Meanwhile, starch, dietary fiber, and cellulose are polysaccharides. That’s an important distinction for those of you keeping score at home: fiber — something most people know as good — is also a form of sugar.

Of those three, we can only digest starch, which is composed of glucose. Starch is also what you’ve probably heard call “complex carbs” or “slow carbs” — slow because the body needs time to break them down into single sugars (notably glucose, the “blood sugar”).

So the idea of a true non-sugar diet means kicking out a lot of foods that are perfectly healthy. Sure, you can live without ingesting sugars, or even carbs … but only because your body can synthesize the glucose its needs out of fatty acids and amino acids.

This happens because your body needs sugar. Glucose is needed as fuel for important functions, like your nervous system and your brain. (Yes, your brain doesn’t only function on glucose, but it does need glucose; and glucose also helps cells interact.)

Maybe more importantly: there are many perfectly healthy foods that contain sugar (see below).

Any no-sugar diet that removes all of the following foods is likely flawed. And that’s the point: any diet that veers towards extremes oftentimes is misguided, and that includes the catch-all “don’t eat any sugar.”

A list of healthy foods that contain sugar.

When Does Sugar Become Bad For You?

Like most things in life, the poison is in the dose.

As we’ve seen, your body actually needs sugars, to the point that it’ll manufacture some even if you avoid all carbohydrates.

We already discussed that body fatness is the main driver of type-II diabetes and obesity. But sugar can contribute to overeating. And, too much sugar also results in an increase in advanced glycation end products, and so in skin damage and a greater risk of cancer and cardiovascular disease.

That’s why added sugar can be dangerous: not because it’s “as addictive as cocaine.”

The real danger with sugar is not that it’s inherently fattening. A gram of sugar is still just 4 calories. And 4 calories will not make you fat.

chocolate chip cookies

However, you can eat a lot of sugar and not feel full. And that’s the typical pattern. You eat some sugar (usually combined with other foods and hidden in beverages)…and then some more…and then some more…and next thing you know a box of cookies are gone, a can of soda, and sugary coffee drink are all gone…and you’re still feeling hungry.

Added sugars are too easy to over-consume. That’s true of every added sugar, no matter how healthy-sounding it may be.

Is Honey Better Than Cane Sugar?

Don’t be fooled into thinking honey or maple syrup or agave is better for you. Sugar is sugar. Even the much-vilified high-fructose corn syrup (55% fructose, 45% glucose, usually) isn’t a lot worse than sucrose (50% fructose, 50% glucose).


What are especially treacherous are sugars in liquid form. You can drink and drink and drink mass quantities of them—enough calories to account for a five-course meal—and yet still feel hungry.

Perhaps it’s unsurprising that soft drinks are linked to the current obesity epidemic. Sodas and colas are by far the main source of added sugar in the average American’s diet, accounting for 34.4% of the added sugar consumed by U.S. adults and children.

In that respect, fruit juices aren’t any healthier. In fact, they can be even worse.

Why? Because the sugar in fruit juice is fructose, which can stress the liver (only the liver can metabolize fructose in any large amounts).

There’s one “sugary” drink that doesn’t pose the same threat: milk.

While milk contains sugar (lactose, a disaccharide of glucose and galactose), it has far less than fruit juice, since milk also contains protein and fat. Back in the day when fats were the enemy, low-fat milk was considered healthier than whole milk; the same isn’t true today.

Now that fats have been (partially) redeemed, whole milk is back in fashion — and backed by lots of evidence.

Is The Sugar In Fruit Bad?

No, fruit is not bad for you. If we could scream it from the mountain tops and plaster over every Instagram feed, we would tell you:

There is no evidence that eating fruit, even in high amounts, will harm your health.

Unlike fruit juices, whole fruits are filling. Apples, though solid, are 10% sugar … and 85% water; that alone makes them very hard to overeat. In addition, recent studies show that whole fruits may help regulate blood sugar.

a bowl of fruit

How Much Added Sugar Is Safe?

Here’s something we can all celebrate: you don’t need to feel guilty each time you eat added sugar. But, you should stay aware of your consumption and do your best not to exceed these limits:

  • 100 calories/day if you’re a woman (about six teaspoons, or 25 g);
  • 150 calories/day if you’re a man (about nine teaspoons, or 36 g)

What does that mean in real food?

That’s the equivalent of about 1 full-sized Snickers bar or about 7-8 Oreo cookies.

snickers bar and oreos

That’s not to say you should add Snickers or Oreos to your daily eating plan. The example simply illustrates the safe, maximum amount you can have each day.

The reason it’s not so simple is that added sugar winds up in a lot of unexpected places, like soup, pizza, and granola.

While the average consumption of sugar in the United States may be decreasing, it’s still way too high.

If you want an easier way to keep your sugar consumption in check, use the guide below. It’s based on the model of the old school Food Guide Pyramid, which was released in 1992 and replaced in 2005 by MyPyramid—before that was eventually replaced by whatever this thing is that the government is using nowadays.

The Sugar Pyramid is a new spin on dietary sanity.

Two pyramids compare healthy vs. unhealthy intakes of added sugar. Healthy has more natural sugars than added, while the reverse is true for unhealthy.

The base of a healthy sugar pyramid is made of vegetables and fruits: Not only are they filling, but they also provide you with fiber, vitamins, minerals, and phytochemicals (biologically active compounds found in plants, some of which are beneficial to our health).

Whole milk also fits into the base of the Sugar Pyramid. The little sugar naturally occurring in bread doesn’t count as added sugar, either—but the sugar that’s often added during manufacturing in the U.S. does.

As for fruit juices, honey, and maple syrup, they all count as added sugar, as does high-fructose corn syrup.

If the base of your personal sugar pyramid is wide, then sprinkling a little added sugar at the top won’t make it collapse. It’s only when most of the sugar in your diet comes from soft drinks, sweets, cookies, and breakfast cereals that your pyramid is likely to topple, and your health along with it.


Do Carbs Actually Make You Fat?

Winning the War on Hunger: Practical Solutions to Overeating

Healthy Fat: Which Foods Should You Really Be Eating?

Kamal Patel is director of, an education company he cofounded in 2011. Since that time,’s growing team of researchers has reviewed thousands of studies on supplementation and nutrition. Today, over a million visitors each month rely on to separate marketing hyperbole from scientific evidence.



  1. Awesome article. It’s good to see you pushing the benefits of fruits, seeing that those usually get demonized in the sugar argument. Also it is very interesting to see the chemical make up between HFCS and table sugar is virtually the same (I didn’t know that before). I definitely will change up my approach on that subject (that is not crucify HFCS in comparison to table sugar).

    One last question: Why didn’t you include blueberries in your fruit list? Nutritionally speaking, they have a high “bang per buck” quota.

    1. Dang, did we miss that? Our bad. Yes, by all means, blueberries are great.

  2. High fructose sugar surely has been demonized in today’s media. I’m curious to know why as it is not being crucified in the article. As a certified trainer, I never stop learning. I spoke to a vegan who said that you should eat your fruits in the morning and afternoon. He also said that you should eat a lot of it. On the other hand some nutritionists say the excess sugar from them can cause you to put on weight. I just consume them in moderation and add them to my smoothies or shakes as a post-workout drink. I believe in balance and using good judgment. One thing I know is that I’ve never met someone who became overweight from eating whole foods (fruits and vegetables).

  3. I have been listening to research that discusses how the brain, while it needs glucose to function, can also use (and prefers?) ketones.

    What are your thoughts on this?

    I can understand how new research can bring about new ideas but I struggle with the topic that ketosis, specifically, in that I don’t understand the science behind how we function without glucose – and if our bodies are smart enough to create it own its own – how does that relate to the presence of ketones?

  4. Great article with an up to date nutritional information. The article is written from an American food pyramid point of view which is different to the Australia guide to healthy eating. However, the remaining content is relevant, easy to understand and well lay out.

  5. nicely explained article related to sugar. we all had misconception about sugar.
    actually it the daily calorie intake that matters,

  6. Very helpful. The way you have broken down everything we need to know about sugar is really good. I love sugarcane juice. I have to cut down drinking it.

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.