Personal training at your door step

Book NOW Free initial consultation with body analysis


Back to all posts

The Truth About Sugar

April 26, 2016 Diet and nutritional guidance dragana

sugar is not bad

In the world of the fitness industry there is no greater villain than sugar.
It is accused of being toxic, addictive and single handedly responsible for driving the obesity epidemic.

In this article we will go through most common claims about sugar, clearing the misconceptions about what sugar really is and what it isn’t.

What is Sugar?

In the simplest term the sugar is carbohydrate or the simplest form of carbohydrate.
It is along with the fats, the body’s primary energy source and the main fuel for the brain.
The simplest form of sugars are called monosaccharides and they can be divided into:

– Glucose
– Fructose
– Galactose

The glucose is the name for the blood sugar, which comes from the sugary food we eat but one that the body also has the ability to make in the liver from the other nutrients.

The fructose or fruit sugar is another simple sugar that can mostly be found in fruit or honey.

The galactose is the type of the simple sugar that can be found in milk.

Where sugar can be found?

Here are several food or food groups that can be classified under the term “sugar”:

  • Granulated sugar, powdered sugar
  • Honey
  • Agave syrup
  • Maple syrup
  • Jams
  • Fruit
  • Chocolates
  • Cakes
  • Pudding
  • High fructose corn syrup
  • Sodas
  • Fruit juices- both packaged and fresh
  • Ice creams

Most of the above mentioned sugar sources will have some different ratios of glucose and fructose in them but will basically be metabolized in the same way once they enter the body after digestion.

So although the pure fructose will be processed differently than pure glucose, the point is that fructose from fruit is going to act completely the same as fructose from high fructose corn syrup once it enters the body.

The only reason why it is better to eat fruit over the high fructose corn syrup is because the fruit apart from sugar contains other valuable nutrients and fiber that can have a lot of benefits for human health.

Is sugar really bad for us?

The simplest answer would be that it depends.
The “evilness” of the sugar cannot be examined in isolation independent of overall context of someone’s diet, level of physical activity and overall lifestyle.

Imagine two different scenarios:

Person A: overweight, sedentary, without any physical activity, eating excess calories from mostly processed food.
Person B: Lean, physically active, regular physical activity, eating in moderation mostly whole minimally processed food.

Do you think that same amount of added sugar in their diets will have the same effect on their health and body composition?
Definitely not.

Now, let’s dig deeper at the most common claims that follow sugar intake.

1. “Sugar is toxic for human body”

The often claim is that sugar in any amount acts as a toxin in the human body and that therefore should be completely avoided.

First of all we need to define the term toxin.
This word is so often used these days that is almost lost its meaning.

By definition, toxins are small molecules, peptides, or proteins capable of causing disease on contact with (or absorption by) body tissues.
They can vary from relatively minor to immediately deadly in some cases.

But what is very important to understand is that everything can be toxic AT SOME LEVEL.
In biology, the popular phrase used is “the dose makes the poison”.

Let’s take an example of Vitamin B.
If you take it too much, the neurological and liver function of your body will suffer. In normal amounts, vitamin B helps us convert food into energy.

It is the same thing with sugar as well.
Although very high level of blood sugar can be toxic for a human body especially if someone is already overweight (diabetic) and eating excess calories, there is no evidence that sugar has the same effects when it’s taken in moderation, especially in the context of already healthy diet and high level of physical activity.

When it comes to toxicity and harmful effect of certain nutrients it’s all about the dose and about the context.
Saying that sugar in any amount and in any situation will damage people’s health is not only inaccurate but scientifically irresponsible as well.

2. “The sugar is responsible for the obesity epidemic”

The claim is that increased sugar consumption is the driving force behind obesity epidemic.

But the actual research does not support the claims that the reason behind obesity epidemic is a single food group even less a food subgroup like sugar.
The weight gain is a matter of total caloric intake which means that the fat to be gained the chronic excess of calories needs to be maintained over some period of time.
In the case of obesity epidemic this excess of calories didn’t come from sugar only, it came from the combination of different food groups that have different ratio of carbohydrates, fats and proteins.

That means that main drivers behind obesity epidemic over the world are increased overall caloric intake and reduce energy expenditure. (Source)

The point is that the sugar is just a small part of a bigger picture, and while it can contribute to caloric excess it’s certainly not the main cause that drives the obesity epidemic.

We already saw that blaming the fat for obesity epidemic during the 80’s was not such a wise claim after all, so how can we rationally just blame sugar as well?

3. “The sugar is more fattening than complex carbohydrates and can stop your fat loss while on a diet”

There is a common believe that to lose fat you need to substitute all simple carbohydrates with the complex one.
So, instead of table sugar, honey, cookies and ice creams you need eat only complex, non-refined carbohydrate sources like brown rice, potatoes, quinoa etc. The moment you have some simple sugar the fat loss is blocked and your diet is ruined.

But is there any truth to that?
Are the calories from sugar more fattening than calories from quinoa?
If we have the same amount of caloric deficit is the fat lost going to be the different dependent of the carbohydrate content?

This study shows that when the caloric deficit is the same people who ate more sugar lose the same amount of fat like the people who it less sugar in their diets.

Another study that lasted 6 month and included 390 participants showed that the group that ate more sugar throughout the study lost the same amount of body weight as the group eating the more complex carbohydrate sources.
This study explicitly showed that as long as the amount of total calories remains the same the added sugar in the diet did not stop the actual fat loss.

That doesn’t mean that you should eat only sugar to lose fat.
There are other reasons why limiting the sugar intake to a certain degree is beneficial.
It just means that you don’t have to panic if you have that cookie while being on a diet.
You can still have some treats and lose the excess weight at the same time.

4. “Sugar is addictive”

One of the most sensationalizing claims is that apparently sugar is more addictive than most drugs, alcohol and nicotine as well.
The reason for that claim is because eating sugar activates the same reward centres in the brain as drugs do.
The independent researcher Anthony Colpo summed this issue very well:

“Well it is true that sugar does that, but it is also true for plenty of other activities like getting a pleasant surprise, receiving money after successfully completing the task, winning a game or even learning a new language.
Just because different activities activate similar pathways and the areas of the brain, it does not even begin to mean that they exert similar physiological effects.
By the way, eating dietary fat also lights up our brain’s “pleasure centers”, as does consuming chocolate and high-calorie foods (both high in fat and sugar)
It is not a big secret that fat and sugar together make a particularly tasty combination, and many of our most notable calorie-rich treats therefore contain both”.

Eating palatable food does trigger the same areas in the brain like the other addictive substances that make us feel good.
But so does almost every pleasurable activity that we can do in our everyday life.
Almost all highly palatable food that we have cravings for have some combination of added fats, sugar and salt.
This combination has power to overwhelm our reward centers in the brain making us crave for more intake even in the presence of constantly high caloric consumption.
So while refined sugar by itself isn’t especially addictive or rewarding (people actually very rarely crave for table sugar in isolation), it is very often used as part of products that contain a combination of several rewarding components such as fat, starch, sugar. (Source)
So only in that combination with other rewarding ingredients the sugar can drive the behaviors that can show the certain signs of addictive elements.

But in isolation, sugar as a substance does not CAUSE addiction in the scientific definition of addiction.

5. “Sugar will make you hungry”

Well, this one is only partially true and again depends on the context in which the sugar is eaten.
If you replace most of your calories with high sugary food you will probably be hungry most of the time because sugar scores very low on a satiety index.
This means that you are not going to be very full after eating even a large amount of sugar.

But if you already eat a diet composed of whole and minimally processed food that is high in protein, fiber and healthy fats, than adding some sugar on a top of already filling diet is probably not going to make you additionally hungry between the meals.


  1. The sugar is not bad or good, it is a source of energy that can impose negative or positive effects on human health and body composition depending on the context of the overall diet someone practices.
  2. Sugar has empty calories, it is not filling and basing your diet around sugary foods will probably lead to some level of nutrient deficiency and long term health problems.
    Plus you would be constantly hungry which would drive additional food intake that will in the long run lead to excess weight gain.
    But as a small part of an already healthy diet, sugar is harmless and even beneficial in some cases.
  3. So if you are overweight, lack the physical activity, and already eating excess calories, than yes, limiting and even totally avoiding extra sugar intake will probably be a very good idea.
  4. But if you are already physically active and lean, watching on your overall caloric intake and you are eating mostly whole and minimally processed food than you can definitely have that ice cream or a favourite chocolate bar as a part of your diet without fear that your health and body composition will dramatically go to ruin.
  5. Our general recommendation is that 80-90% of your diet should be centred on whole and minimally processed food like vegetables and fruits, lean meats, fish, nuts, legume, non-refined grains and dairy products.
    The rest of your diet can be filled in with whatever you like to eat for that particular day as long as your total calories are in check.

So stop worrying and feeling guilty if you had that cookie after the lunch.
In the big scheme of things it literally doesn’t mean anything if the rest of the time you are doing a good job with your food and exercise.

Milos Rankovic, personal trainer