Most reputable health organizations (if not all) recommend keeping your daily intake of sugar to as low as possible. At the same time, these same organizations acknowledge that carbohydrates are an essential macronutrient that the body needs to properly function and that about 50% of our caloric intake should come from them.

Now, aren't these two recommendations completely contradictory? All carbohydrates that the body can absorb eventually get turned into glucose, a simple sugar like any other.

Why is it bad to consume a bunch of table sugar (sucrose), for example, which is already half glucose and its other fructose half will also get converted into glucose anyway, but perfectly fine to consume other more complex carbohydrates that just like sucrose, will also end up being converted into glucose?

If both, simple sugars and all other carbohydrates end up as glucose in the body, then why does one get a bad rep and not the other? What's the difference?

3 Answers 3


Correct me if I'm wrong but, the sort of sugar consumption that gets a bad rap is the consumption of simple sugars that result in empty calories. In other words, the consumption of sugar-laden, low-nutrient foods.

Sugary drinks form a fine example, from pops to fruit juices: In an 8 fl. oz. serving of cranberry juice, I might consume 35g sugar. I don't get any protein, or fiber, but I get a fine dose of vitamin C; you get your 100% recommended daily value of vitamin C from a variety of sources.

So I consumed 35g of sugar and I didn't consume anything else. If my lifestyle is sedentary, a lot of this sugar goes to the fat stores. However, 8 fl. oz. of cranberry juice never filled anyone up, either, and so it's quite easy to imagine that over time, as a percent of total nutrients for the day, multiple instances of "35g aqueous sugar" starts to become somewhat overwhelming.

This is also why health organizations make the recommendation to switch from enriched, bleached flour products to whole grain products. The flour refinement process ends up stripping the natural nutrients, which they attempt to add back at the end of the process (just an example).

Nutrient density should be a key consideration in the types of sugary foods you consume. But, keep in mind this depends entirely on each individual's diet plan, and so here I've made broad statements.

  • 1
    Then the problem is the "empty calories", not the sugar itself. If those same juices were full of complex carbs instead of simple sugars, you would still have the same problem of "empty calories". Then why do we keep focusing on the sugar?
    – user3113
    Commented Jun 2, 2017 at 19:13

It is all down to the type of carbohydrates you consume. There are 2 main types of carbohydrate and they are simple carbs (sugars) and complex carbs (polysaccharides).

Because of their structures, sugars are metabolised more quickly in the body compared to complex carbohydrates. Therefore, sugars get turned into glucose more quickly for energy use, hence the term "sugar rush" from the build up of energy in the body. Any unused glucose will end up as fat and stored in the body's fat reserves.

Sugars are found in a variety of natural food sources including fruit, vegetables and milk, and give food a sweet taste.

Sugars can be categorised as single sugars (monosaccharides), which include glucose, fructose and galactose, or double sugars (disaccharides), which include sucrose (table sugar), lactose and maltose.

What makes complex carbs different is that they are starches formed by longer saccharide chains, which means they take longer to break down.

Chemically, they usually comprise of three or more linked sugars.

When dietitians and nutritionists advise having complex carbohydrates, however, they are usually referring to whole grain foods and starchy vegetables which are more slowly absorbed than refined carbohydrate.

Whole grain starches include the wheat grain and kernel which provide the majority of fibre and nutrients to be found in starchy foods.

When it comes to picking starchy foods, such as rice, bread and any other products made from flour, it’s best to opt for whole grain versions of these products.

We should not rely too much on carbohydrate though. Whilst whole grain foods impact upon blood glucose levels more slowly than other forms of carbohydrate, higher levels of carbohydrate can still raise blood sugar levels substantially. So whilst aiming for complex carbohydrates rather than simple carbs, you still need to keep within the recommended daily calorie intake and ratios of carbs to other nutrients such as vitamins and fibre.


There are two problems with eating plain sugars. The first problem is that plain sugars are empty calories, causing you to miss out on essential nutrients as explained in detail in CMosychuk's answer. Another problem is that the insulin spike is different when eating plain sugar or the same amount of sugar found in fruits, see here and here. The higher insulin spike after eating plain sugars causes glucose levels to drop below ideal levels, triggering a release of fatty acids. It is this response that causes damage to the body. The same mechanism plays a role in the progression of pre-diabetes to full blown diabetes.

  • 3
    Is youtube really the only place you can find support for that? Most people, me included, hate having to watch a video just to get info we could read in 30 seconds.
    – Carey Gregory
    Commented Jun 2, 2017 at 5:52
  • 1
    @CareyGregory I'll add in the refs from the video later today. Commented Jun 2, 2017 at 20:33
  • @CountIblis It would be great if you could find the time to update your sources.
    – Narusan
    Commented Jun 20, 2017 at 20:09

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