Simple Vs. Complex Carbs

Carbohydrates are a tricky issue in nutrition. On the one hand, most healthy eating food pyramids like the Standard American Diet are based on eating a lot of carbs – 60% or more of calories coming from carbohydrates and fat being kept very low.

Standard American Diet food pyramid

Image Source: wikipedia

On the other hand, some diet and weight loss experts believe that consuming fewer carbs is not only best for weight loss but is healthier too. Very low carb diets only recommend 10% or even less of calories coming from carbohydrates with the rest coming from fat and protein.

Arguments for and against carbs aside, it’s important to understand that labeling all carbs as good or bad is very shortsighted as there are several different types of carbs, the main division being simple vs. complex. All carbohydrates contain four calories per gram and are used by your body for energy. While some carbs digest quickly, others digest slowly but they all contain the same number of calories. However, all carbs should not be grouped together.

In this article I’m going to explain the difference between simple and complex carbs so you can decide which type is best for you and then choose whether you should eat more or less carbs to lose weight. I’ll try and keep this simple to understand but this is a big subject!

Simple carbohydrates 

Simple carbohydrates, also known as sugars, have a simple molecular structure, hence their name, and are made of one or two sugar molecules. Simple carbs made up from one sugar molecule are called monosaccharides:

  • Glucose – the most common sugar
  • Fructose – found in fruit
  • Galactose – found in dairy

Simple carbs made up from two sugar molecules are called disaccharides:

  • Sucrose – glucose plus fructose together
  • Lactose – glucose plus galactose together
  • Maltose – glucose bound to glucose

The fact that simple carbs are also known as sugars make some people think that they are unhealthy but this is not always the truth. For example, while white table sugar (sucrose) is definitely unhealthy, the sugar found in fruit (fructose) is actually pretty good for you as it comes with lots of vitamins, minerals, trace amino acids and fiber.

Of course, there is a big difference between naturally occurring simple carbs and refined simple carbs. To know the difference, all you need to do is think “does this food grow in nature?” If the answer is yes, even though it’s a simple carb, it’ll probably be good for you. However, if it’s manmade, it probably isn’t.

Here’s a chart to help clarify this point:

“Good” simple carbs“Bad” simple carbs
BananasCakes and cookies
MilkJuice made from concentrate
Freshly squeezed juiceFoods with added sugar

Simple carbs often get a bad name but, as you can see, some of them are actually pretty good for you. Of course, if you want to lose weight and be healthy, you need to eat much less of the bad ones.

Complex Carbohydrates

This type of carbohydrate made up from complicated chains of sugar molecules called polysaccharides – poly meaning many. Because of their more complex structure, they are called complex carbohydrates but another name for them is starches.

Starches are often thought of as more healthy than simple carbs but this is not always the case, as you will see in a moment.

Complex carbs include foods like bread, rice, pasta, potatoes, and other vegetables as well as grains and cereals. Low in fat, many people eat a lot of complex carbs and, in fact, they are the backbone of many diets.

The thing is, despite their healthy reputation, complex carbs can be good or bad. For example, white bread is a complex carb but most people understand that too much white bread is unhealthy. Potato chips are also a complex carb and everyone knows they aren’t healthy!

So what makes a complex carb good or bad? It’s usually down to the amount of processing it has been through. Carbs that are in a very natural state are called unrefined carbohydrates whereas those that have been processed are called unrefined carbohydrates.

As a rule, unrefined carbohydrates are much healthier than refined carbs.

Here is a chart to help clarify the difference:

“Good” unrefined carbs“Bad” refined carbs
Wholemeal pastaWhite pasta
Brown riceWhite rice
Unrefined grains e.g. quinoa, buckwheat, speltFrench fries
PotatoesMost “readymade” meals
VegetablesWhite bread

Turning an unrefined carbohydrate into a refined carbohydrate normally involves removing important nutrients such as vitamins, minerals, and amino acids but the most important thing processing removes is fiber…


Fiber is a form of carbohydrate. It’s found in both simple and complex carbs. It is indigestible and so it essentially contains no calories. However, just because fiber is calorie-free, doesn’t mean you don’t need it!

The proper name for fiber is non-starch polysaccharide or NSP for short and it comes in two types – soluble and insoluble.

Soluble fiber dissolves in water and can be found in the flesh of plants and grains. As it passes through your body, it helps soak up excess bile acid and cholesterol which means it’s very good for your health.

Insoluble fiber does not dissolve in water and is found in the tough skins of fruit and vegetables and the outer husks of grains. It passes through your digestive tract acting a bit like a scouring brush and helps keep your intestines clean and healthy.

You need both types of fiber and the recommended daily allowance is 14 grams for every 1000 calories you eat. Therefore, if you eat 2000 calories per day, you should try and get 28 grams of fiber, split evenly between soluble and insoluble.

The easiest way to get more fiber is to eat a reasonable amount of healthy, unrefined carbohydrates in the form of vegetables, fruits, and whole grains.

Going Low Carb

the easy low carb diet by days to fitnessSo will cutting carbs help you lose weight? Yes – it can! Cutting carbs means you will consume fewer calories overall and also eliminate any competition for fuel that happens in your body. If you cut carbs, your body is more likely to use fat for energy.

But, you need some carbs to fuel activity and also provide the vitamins, minerals, and fiber your body requires to stay healthy.

You can cut carbs and still get all the nutrients you need by eating more fruit and vegetables while eating fewer grains and little or no refined carbs.

There are very low carb diets, called ketogenic diets, that virtually ban all carbs but you don’t need to go this far unless you really want to. Ketogenic diets are a topic best left to another article! Simple eating more vegetables and less bread, rice, pasta, and potatoes can often lead to weight loss without having to cut carbs entirely. Check my Easy Low Carb Diet.


So, now you know the main differences between simple and complex carbs, refined and unrefined carbs, and also know a little more about fiber. This should all help you choose which types of carbs to eat (unrefined) and which carbs to avoid (refined) to lose weight and stay healthy.

what are carbs my carbs guide

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Hi, my name is Sarah and I’m so happy that you’re here! I've shared my story here

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