Carbohydrates are one of the three macro-nutrients (sources of fuel).
There are 3 types of carbohydrates:
Simple sugars, like fructose, lactose and glucose. They are found in naturally occurring foods such as fruit, honey, maple syrup, milk (lactose) and vegetables. (See what is the difference between glucose and fructose here.)
1 gram of simple sugars = 4 Cal
Starch, which is made of chains of simple sugars bonded together. Cereal grains, rice and potatoes are considered starchy foods. In addition, foods made by processing the previously mentioned foods, such as pasta, bread, pizza base, biscuits, etc. are in the same group. Starch breaks down into simple sugars fairly rapidly in the body and then gets converted to energy just like simple sugars.
1 gram of sugars from starch = 4 Cal
Fiber, only found in plant foods. Fiber is not absorbed in the small intestine like other sugars. Instead, it passes to the colon where it is partially fermented, generating energy.
1 gram of fiber = 2 Cal
(This is an average estimation, since the exact figure depends on many factors, one of which is the proportion of fermentable fiber.)
The healthiest sources of carbohydrates
The best and the healthiest dietary sources of carbohydrates are those rich in a large variety of nutrients and fiber, with a low Glycemic Index and Glycemic Load. The reason is that we don’t need high amounts of carbohydrates. A small amount of carbohydrates is sufficient. This means that, taking this into consideration, the chosen diet must assume the most nutritious form. After all, we only have a limited capacity of how much to eat per day so we might as well make our choices carefully.
There are two main reasons why some carbs are considered bad:
- Bad carbs have a high Glycemic Index and are digested and absorbed quickly, having a negative impact on the insulin level. Bad carbs are the one of the reasons for the current obesity epidemic in developed countries, which has gotten out of control from the moment an “anti-saturated fat” and “pro-carbohydrate” campaign started in the late 70s in the U.S. It is believed that the rise in cardiovascular diseases and type 2 diabetes has resulted from the increased intake of carbohydrates over the last four decades.
- People normally tend to overeat foods containing bad carbs, since the body does not possess the ability to recognize in time when to stop. By contrast, the body is able to recognize in time when we had enough protein and fats.
Any products with added sugars or containing high contents of processed carbohydrates, such as white bread, pasta and white rice, contribute mostly with energy and have very few other nutrients. They also have a high Glycemic Index and Glycemic Load and are associated with the increased risk of cardiovascular disease, obesity and type 2 diabetes.
Please note, however, that sugars should not be treated like a poison. Once you have a balanced diet (especially controlling the use of carbohydrates), adding a teaspoon of sugar won’t do any harm. The Glycemic Load of the whole dish will still be low because of the other ingredients, posing no health issues.
Adding high Glycemic Index foods to your diet poses, however, a big problem. Unless you are used to a balanced diet and don’t rely on carbohydrates as your main source of energy, you may not know how much is too much.
Starchy vegetables, such as potatoes, also have other nutrients but their high content of starch and high Glycemic Index places them on the “no good” list.
For people who want to lose weight, the best way is to eliminate all processed carbohydrates and to eliminate or drastically reduce starchy foods, such as potatoes. Those who are currently on a high carbohydrate diet may see it as extreme, but when on a low carbohydrate diet people do tend to lose cravings for such foods.
For those whose diet is balanced and metabolism rate is high, having carbohydrates (preferably unprocessed) with protein and good fats won’t have an impact on the insulin level. This applies especially for athletes and physically active people who want to replenish their carbohydrate energy stores after a prolonged or intensive exercise. It has been shown that athletes may benefit from a high carbohydrate meal after an intensive workout with no negative impact on insulin sensitivity.
Whole grain products
In recent decades, whole grains (e.g. wholemeal bread, wholemeal pasta and brown rice) have been recommended as the best alternative to processed grains by most governments and health institutions. They are the largest recommended food group of the current food pyramid.
Being whole means that they are not stripped of the wide variety of nutrients held within the outside fibrous layer of the grains.
Nevertheless, being whole doesn’t make much difference in their high Glycemic Load, which is responsible for all sorts of health issues.
They are a better alternative when compared to processed carbs, but can still be substituted for much healthier alternatives, such as vegetables, fruit and legumes, which are not only nutrient dense but also tastier.
Please note that there are some studies showing the benefits of whole grain cereals but these studies are often misinterpreted. (read more..)
Tropical fruit and juices
Some tropical fruit are also high in simple sugars and may have a high Glycemic Load so need to be eaten in moderation. Fruit juices (even if natural) are very high in simple sugars and should be avoided.
Good carbs come in the form of high fiber vegetables and fruit, nuts, seeds, beans, lentils and peas.
These foods are loaded with a wide variety of nutrients and provide plenty of fiber.
By eating good carbs foods, you not only get energy but also the essential minerals and vitamins for the body to function properly.
These foods are also rich in phytochemicals which, although not essential for survival, contribute to optimal health.