Carbohydrates or good carbs, bad carbs… What’s so bad about them? Why low carbs diets are so popular? What are the benefits (or maybe dangers) of low carbs intake? How much carbs should I take what carbs should I choose and what should I avoid? What do they have with sugar? – If same questions have ever crossed your mind – join me on my research!
What are carbohydrates?
Carbohydrates are one of the three macro nutrients (proteins, fat and carbohydrates), technically – hydrates of carbon also called – saccharides.
Simply speaking, carbohydrates are sugars, starches and fibers found in fruits, grains, vegetables and milk products. They are one of the three main ways the body obtains energy, or calories. Carbohydrates provide fuel for the brain, central nervous system and energy for working muscles.
In our body carbohydrates are broken down by enzymes into smaller units of sugar. The liver converts all of these sugars into glucose, which is carried through the bloodstream accompanied by insulin and converted into energy for basic body functioning and physical activity. If the glucose is not immediately needed for energy, the body can store up to 2,000 calories of it in the liver and skeletal muscles in the form of glycogen. Once glycogen stores are full, body stores carbs as fat.
Starch is a type of complex carbohydrate and is found in a wide range of foods, including potatoes and whole grains. Starch breaks down into glucose in our body, providing more gradual energy source for our body.
It is divided into two types according to its chemical structure: amylose and aminopectin. Amylose is more difficult to absorb than amylopectin, which means that it is more beneficial to us.
Scientists have found that there is a Resistant starch, which is not digested in the small intestine and unchanged, reaches the colon, where realizes its excellent health properties – stabilizes blood sugar, reduces resistance to insulin, increases the absorption of minerals (especially calcium and magnesium), has properties of prebiotics, forms friendly flora.
Fiber is essential to digestion. It promotes healthy bowel movements and decreases the risk of chronic diseases such as coronary heart disease and diabetes. Unlike sugars and starches, fibers are not converted to glucose, but to hydrogen, carbon dioxide and fatty acids.*
Types of the resistant starch *:
- Resistant starch found inside the indigestible cell walls of plants – uncooked grains, seeds, legumes
- Granulated natural amylose – considered indigestible unless it is heated, found in maize, uncooked potatoes, unripe bananas
- Retrograded starch, which has a special, restored amylose form in heat-treated food, such as bread, boiled potatoes, rice, pasta. When the products cool down, the starch takes its crystalline form, which is not broken down by enzymes.
- Chemically modified starch – unnatural and not advised.
Resistant starch is found in raw potatoes, unripe bananas, oats, cooked and cooled potatoes and rice and legumes.
Are all carbohydrates equal?
Carbohydrates are our body’s primary energy source and should never be avoided. But not all carbs are alike.
Complex carbohydrates, such as whole grains and legumes, are longer chain molecules of sugar. The body needs more time to break it, ensuring even energy supply over a longer period of time.
Simple carbohydrates, such as white flour, sugar, break down much faster which gives us the energy bursts by causing blood sugar spikes. ***
Time needed to digest carbs is determined by:
- Carbohydrate chemical properties
- With which other macronutrients carbohydrates were consumed
- How the food was prepared
- Person’s metabolism ****
Good carbs, bad carbs
There is a reason why we hear about good and bad carbohydrates. Our body gets the most from the good (complex) carbohydrates – it ensures even energy supply, well-being and good mood. The fiber in good carbs keeps the gastrointestinal tract healthy, slows the supply of glucose to the bloodstream.
Complex carbohydrates generally have less calories, are naturally rich in nutrients and fiber and low in trans fat. The good carbohydrates are: whole grains, vegetables, brown rice, legumes.
Meanwhile, bad (simple) carbohydrates, also called empty calories, increase the risk of overweight and diabetes, cause heart diseases, mood swings, and sugar cravings.
Simple carbohydrates cause a spikes in blood sugar and at the same time bursts of the energy, but this won’t last long. Soon the sugar curve drops down drastically – we feel tired, sleepy, overwhelmed, the feeling of hunger returns very fast and we also want to eat something sweet.
Over a long period of time, regular consumption of simple carbohydrates causes sugar cravings, frequent hunger, energy and mood jumps, weight gain, health problems such as fatty liver, hormonal disorders, stomach flora imbalance, cardiovascular diseases, diabetes and many others. Permanent high blood glucose levels contribute to the development of insulin resistance, which leads to diabetes.
Simple carbohydrates often are higher in calories, refined sugars, white flour, low in nutrients and fiber, often rich in trans fats.
Bad carbohydrates include: white flour pastries, sweet drinks, processed food, white rice, white bread, sugar and its products.
Fruits and vegetables are actually simple carbohydrates — still composed of basic sugars, although they are drastically different from cookies and cakes. Why? The fiber in fruits and vegetables changes the way that the body processes their sugars and slows down their digestion, making them a bit more like complex carbohydrates.
Glycemic index and glycemic load
The glycemic index (GI) is used to describe food behavior during digestion and their potential to raise blood sugar level.
So basically, glycemic index shows how quickly food glucose is absorbed – slower is better. Low GI foods tend to help weight loss, while foods high on the GI scale help with energy recovery after exercise. Slow release of glucose in low – glycemic foods is helpful in keeping blood glucose under control.
But the glycemic index of foods tells only part of the story. What it doesn’t tell you – how high your blood sugar could go when you actually eat the food, which depends on the size of the portion. To understand a food’s complete effect on blood sugar, you need to know how quickly the food makes glucose enter the bloodstream, and how much glucose it will deliver. Glycemic load describes that. It gives more accurate picture of a food’s impact on blood sugar.
For example, watermelon GI = 72 – very high (avoidable). However, there is not much sugar in the watermelon in general – up to 10% (or 10 grams in one hundred grams of watermelon), so its actual sugar effect is less harmful than most products with significantly lower GI. Potato chips may turn out to be innocent under the glycemic index, but their real impact is much worste. ***
A glycemic load of 10 or below is considered low; 20 or above is considered high.***
Glycemic index may change
That number is a starting point on paper. It could be different on your plate, depending on several things:
- Fat, fiber, and acid (such as lemon juice or vinegar) lower the glycemic index. The longer you cook starches like pasta, the higher their glycemic index will be
- The glycemic index of fruits like bananas goes up as they ripen
- Other foods eaten at the same time. Bring down the overall glycemic index of a meal by combining a high-glycemic index food with foods that have lower ones
- Your age, how active you are, and how fast you digest food**
How much carbs do we need? Ketonic diet
According to the recommendations, carbohydrates should make up 45-65 percent of our daily calorie intake. If we consume 2000 cal per day, we would need to eat between 900-1300 cal or 225-325 grams of carbs. Obviously, these carbohydrates should be complex. The daily sugar intake should not exceed 50 g, but according to many experts – only 25 g.
Low carb and ketogenic diets are becoming more popular.
Low-carbohydrate (60-130g, 240-520kcal) diets are often offered to lose weight. Carbohydrates are replaced by protein and fat.
Ketogenic diet helps not only to lose weight, but also heal certain diseases, such as cancer, diabetes. The cancer cells mainly feed on glucose. Ketogenic diet limits carbohydrates to 50g per day or completely eliminates them. The body, without getting carbohydrates and unable to make glucose, starts to produce energy from fats and to release ketones – the end-products of fat metabolism. Energy is produced from fat which comes from food and if you limit the number of calories – from the body fat.
A ketogenic diet also lowers blood glucose, which also means lower insulin levels. High insulin is a risk factor for cancer, as it stimulates cancer cell growth. Lower insulin also helps in losing weight, because insulin stops burning processes.
Dietitians disagree whether proteins and fats fully replace carbs. Studies have proven its benefits in weight loss and disease control, but what about long-term health impact? Some say that body needs protein to make muscles and using protein instead of carbohydrates for fuel also puts stress on the kidneys. Proteins are also much more difficult to digest due to lower acidity of the stomach, and also with age.
Other specialists say that people can stay on ketonic diet all the time. It is our decision to make what is best for us. Just to mention that there are essential proteins (to be more precise, its components – amino acids) and essential fats, without which our body couldn’t survive. However, there are no replaceable carbohydrates – if they are missing, body just starts using fats and proteins.
- Lower your intake of carbohydrates if you try to lose weight; if you plan to give up carbohydrates for a longer period of time, do so with your doctor
- set a goal of 40–65% of total energy from carbohydrates, but only 5% directly from sugars
- always choose complex good carbs; make them the base of your everyday diet
- choose products with the resistant starch
- Check the glycemic load of your favorite foods; replace high index products with healthier option
- If you can’t give up on simple carbs, them on occasion; don’t make them your primary source of energy
- replace cookies and cakes with fresh or dried fruit; make cakes and pies at home – this way you can control the quality and sugar amounts
*http://neovital.lt/straipsnis/nauja-sveikos-mitybos-tendencija-atsparus-krakmolas-padeda-liekneti/ ** http://www.livescience.com ***https://en.wikipedia.org/wiki/Carbohydrate ****http://cosport.lt/mityba/trilogija-kaip-skaityti-maisto-produktu-etiketes-3-dalis-angliavandeniai *****http://www.health.harvard.edu/diseases-and-conditions/glycemic-index-and-glycemic-load-for-100-foods ******http://www.webmd.com