Complex carbohydrates, in contrast to simple ones, give up their energy gradually during digestion - this is why they are also called "slow." Essentially, complex carbohydrates are made up of long chains of compound molecules, while simple carbohydrates are short and easily digestible structures.
Most diets for weight loss (just like the rules of a healthy diet) involve the maximum rejection of foods with simple carbohydrates and their replacement with complex ones. The main reason is an attempt to normalize blood sugar to create a feeling of long satiety.
// What are complex carbohydrates?
Complex carbohydrates are polysaccharides that contain long chains of molecules. If typical examples of simple carbohydrates are glucose and fructose, then complex carbohydrates include starch (the main carbohydrate of plants), glycogen (the main source of muscle energy), as well as water-soluble and water-insoluble dietary fiber - cellulose, pectin, and so on.
Since complex carbohydrates are composed of many structural elements, the body needs time (and effort) to break down and assimilate them, while simple carbohydrates are absorbed as quickly as possible. The role played by the fact that fiber is such a complex structure that it is not digested in the human stomach - however, plays an important role in the digestion process.
Also, some products with complex carbohydrates have the properties of prebiotics - that is, they provoke an increase in the population of beneficial intestinal microflora. This has a positive effect on both improving digestion and increasing immunity, as well as lowering blood cholesterol. In contrast, sugar and other fast carbohydrates inhibit bowel function.
// What about complex carbohydrates?
Healthy and harmful carbohydrates
Despite the fact that complex carbohydrates alone cannot affect the process of losing weight, any diet for weight loss implies the maximum rejection of simple carbohydrates and their replacement with complex ones. The main reason is the desire to normalize blood sugar. It is the sudden changes in sugar levels that fuel your appetite and make you eat more.
In fact, complex carbohydrates guarantee long-term saturation and a gradual increase (and further smooth decrease) in blood insulin and glucose levels - in simple words, complex carbohydrates are low-glycemic carbohydrates. The use of such carbohydrates is more beneficial for the body than the use of refined sugars.
Cereals - Sources of Complex Carbohydrates
Most cereals (including buckwheat and quinoa) are an example of complex carbohydrates. They contain both starch and fiber - while the presence of simple carbohydrates (sugars) is minimal. The unique difference of oatmeal is that the fiber contained in it is water-soluble and can absorb liquid - thanks to which it provides long saturation and normalizes the work of the stomach.
In addition to the above, complex carbohydrates are found in nuts, all kinds of seeds, legumes (peas, lentils, soybeans) and in the shell of grain (bran). Also, a lot of carbohydrates with a long assimilation time is a part of vegetables and fruits - however, in sweet fruits (bananas, peaches, grapes), a significant part of carbohydrates falls on digestible fructose.
// List of complex carbohydrates:
- Vegetables and some fruits
- Beans, Lentils
- Nuts and seeds of plants
- Cereals, flour
Carbohydrates: simple or complex?
We make a reservation that complex carbohydrates are not always extremely useful. For example, starch contained in wheat and white rice is a complex carbohydrate in its structure - however, the body is able to quickly absorb it. Maltodextrin is similarly composed of long structural elements, but in the stomach it behaves like a simple carbohydrate.
The most difficult products to categorize are wheat pasta. Depending on the wheat variety, cooking method, portion size and the amount of the additional side dish, pasta can have both a high glycemic index (i.e., are simple carbohydrates), and medium and even low (formally referring to a useful carbohydrate of long absorption).
The more fiber, the better.
The more fiber is contained in a particular carbohydrate product, the lower its glycemic index and the more confident it can be considered a useful complex carbohydrate. For example, one hundred grams of dry beans consist of 60 g of carbohydrates (a quarter of which is fiber) and 20-25 g of protein - this product definitely refers to healthy carbohydrates.
On the other hand, in potatoes, which formally refers to complex carbohydrates, there is practically no fiber - most of its weight falls on starch. Boiled potatoes have a high glycemic index and should be used with caution when following a diet for weight loss. The role is played by the fact that the content of vitamins and minerals in potatoes is minimal.
Where are complex carbohydrates?
A certain amount of simple and complex carbohydrates is contained in any plant product - only a few of them consist exclusively of carbohydrates of the same type. However, if fruits contain more fructose than fiber (thus referring to simple carbohydrates), then any cereals and grains are complex carbohydrates. Even if they contain exclusively starch.
Ultimately, it’s more accurate to take into account the glycemic or insulin index of a particular food product, and not just rank it as useful or harmful carbohydrates. In addition, the degree of processing also affects the role - brown rice is much healthier than white rice with a removed shell. Although in both cases, rice is a complex carbohydrate, but the presence of fiber balances the effects of starch.
Complex carbohydrates = heavy carbohydrates?
It is sometimes believed that foods with complex carbohydrates must be consumed before lunch - they say, when consumed in the evening they create heaviness in the stomach and interfere with normal sleep. This opinion is erroneous. Fiber contained in such products not only does not create heaviness in the stomach, but also helps digestion. Complex carbohydrates are especially beneficial at night.
However, as before, we are talking about complex carbohydrates with a low glycemic index - starch or maltodextrin are acceptable only in the morning, or as an energy source after strength training. Those who want to lose weight are advised to refuse starchy foods, replacing them with fiber-rich vegetables or whole grains.
Complex carbohydrates are a type of polysaccharide with a long chain of molecules. Examples of such carbohydrates are starch, glycogen and fiber. The benefit of a particular carbohydrate is determined by its glycemic index and how quickly the energy contained in it is absorbed by the body. Maltodextrin and starch, formally considered complex structures, behave like simple carbohydrates.