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Today I will explain you everything you need to know about the 3 main categories of nutrients in our food, which ones should be consumed in smaller quantities, and why vegetables should be the kings of your diet. This might be a -kind of- long lesson, but it will build strong foundations of your knowledge about what is healthy and what is not.
So, let's do it!
PS. In this lesson I will use a lot of terms, in the easiest way- don't worry, but in case you forget what something means press Ctrl+F (in windows) or Command+F (in Macs), type it in the little window that will appear and find it in all the spots it appeared.
The two big categories of nutrients: macro- and micro nutrients
People tend to get lost in understanding the nutrients that their food contains. Let's dive in the two big families of nutrients: the macro- and micro-nuntrients.
A small introduction on micro-nutrients
Micronutrients are what are commonly referred to as "vitamins and minerals." Micronutrients are different from macronutrients because they are necessary only in very tiny amounts. Nevertheless, they are essential for good health, and their deficiencies can cause serious health problems. Micronutrients include such minerals as flouride, selenium, sodium, iodine, copper and zinc. They also include vitamins such as vitamin C, A, D, E and K, as well as the B-complex vitamins. Vegetables and fruits contain big amounts of them, so they are considered good sources of micronutrinets and fibers. Are you curious about their other benefits?
- Maintain a healthy body: Vegetables contain low amounts of fats and calories and are good sources of dietary fibers. The low fat and calorie content of vegetables makes them a perfect substitute for foods with higher calorie content, such as carbohydrates and proteins. Owing to their high fiber content (fibers slower down the digestion), raw vegetables leave you feeling full for longer and hence reduce food cravings. Also, raw vegetables contain higher amounts of antioxidants. These antioxidants include vitamins C and E, folic acid, lycopene, alpha-carotene and beta-carotene. Vitamins C and E neutralize free radicals and protect your body cells. Lycopene- a naturally-occurring pigment in colored vegetables such as tomatoes and apricots -- boosts your immune system and also lowers the risk of cardiovascular disease. Folic acid is necessary for the formation of red blood-cells and proper functioning of the brain and nervous system. Beta-carotene, found in brightly colored vegetables, protects the skin from the sun’s harmful ultraviolet rays. It also slows down the aging process and reduces the risk of diseases associated with old age.
- Keep your heart healthy: Eating foods rich in fiber is associated with a lower risk of developing heart ailments. The water soluble fibers found in vegetables, such as gum, pectin and psyllium, form a gel-like matrix. In your cells, this gel absorbs bile acids and bad cholesterol (Low density cholesterol -LDL) and eliminates them from your body. Since bile acids are formed from LDL cholesterol, your body tries to replenish them by using the LDLcholesterol available in the bloodstream. If LDL cholesterol circulates in the bloodstreat for long, it sticks on the walls of blood vessels (like dirt in pipes), making them narroer and leading to cardiovascular diseases.
- Lower the cancer risk: Extensive cooking lowers the volume of anticancer compounds known as isothiocyanates and glucosinolates in the brassica family of vegetables. Eating raw cruciferous vegetables such as broccoli is a good way to lower the possibility of developing cancer.
My conclusion would be to consume 3-4 servings of vegetables and fruits per day. Try to consume vegetables of different colors and different families, as each one is rich in different micronutrients and you need a little bit of all.
A small introduction on macro-nutrients
The three main macro-nutrients out of foodsare the carbohydrates (from bread, pasta, rice etc.), the proteins (fish, eggs, meat, lentils etc.) and fat (oil, butter, nuts etc.) and you should receive all three of them daily from your diet. Let's see each category separately.
1. Dietary carbohydrates (carbs for shorter) are combinations of sugar units (called glucose) that come in both simple (glucose, fructose, sucrose) and complex (polysaccharides; dietary starches) forms.
- Glucose is the basic structural unit that all carbohydrates consist of; think of glucose as the single lego brick, with which you construct everything. During digestion of food, all carbohydrates are broken down to glucose. Glucose is absorbed in our gut and it is the fuel that produces energy that our body uses right away for allour cognitive and body functions; think of glucose like the charcoals that feed the fire.
- Now, listen to that: if the energy demands are low, glucose is not used to make usable energy, but it is stored in the fat tissue (adipose tissue). Because, fat tissue is nothing else than a storage of energy for when we have accessto food, see how wise your body is?
- Something to be cautious about: during starvation periods, your body can convert its saved fat into glucose and generate energy to move, etc.. However, the brain uses only the glucose from the carbs of each meal. If you are not eating enough carbs and you have headaches, lack of concentration and bad mood, now you know the reason.
- Also, let me introduce aterm that I will use a lot from now on: the glycemic index. The glycemic index is the measure of the speed at which glucose is released into the blood stream after digestion. Big amounts of sugar are toxic and inflammatory for our body. Insulin is released in the bloodstream to lower down all this circulating glucose. So, in a nutshell, foods that have high glycemic indexes, result in spikes of insulin too. In will explain in a bit, why such types of food are catastrophic for a healthy diet. How can you lower the release of the glucose in the blood? By eating food that contains fiber (whole grain carbs, but mainly vegetables and fruits) or by combining the carbohydrates you eat with rich in protein and fat food (proteins slower down the glucose release, slowering the release of insulin and, in a nutshell, keeping you full for more time).
2. Dietary proteins are vital for the well-being of the body; they are the structural units that our body uses to build and repair muscles and to perform many other important functions. All thousands of human proteins (maybe 50.000) consist of different combinations of 20 types of amino acids (the primal structural units of proteins). Our bodies can produce only 11 amino acids on their own, and 9 of them have to be obtained through food. However, if proteins that we obtain through food are not used immediately, they are broke in amino acids and they are used for energy. And if they're consumed in excess, they can be stored in fat tissue, as well.
3. Dietary fats are separated in 2 big (natural) families (unstaurated and saturated ones) and one artificial man-made one (trans fats). For these categories I will talk in depth, a bit below. Fats can also be broken down into smaller components and be used for energy. Or, they can be stored in fat tissue, depending on our energy needs.
Fats are the most energy dense storage form, providing nine calories of energy for every gram. In contrast, carbohydrates and proteins provide only four calories per gram. For the record: alcohol provides seven calories per gram!
So remember: No matter from which macro-nutrient they derive from (carbs, proteins, fats), any calories that aren't converted into usable energy, will be stored in the body for later use.
2nd lesson: The truth behind carbohydrates, fats and proteins
So, now that you know the main ingredients of your food, do you feel ready to make healthier food choices? The answer is not yet, but you are almost there. What you lack is the knowledge of how many of these vital macronutrients (because all of them are absolutely vital) are optimal for each meal. Because, you know, not all nutrients are equal especially when it comes how they affect our diet. So let's dive on that; you will love this part, I think, as it contains tips you can apply in your everyday diet.
Let's dispel some myths regarding eating carbohydrates, proteins and fats:
The truth about dietary carbohydrate
In the recent years, a lot of attention has been drawn on how healthy carbohydrates are. There are lots of popular diet trends that encourage us to drastically reduce the carbohydrates in our diet. However, there are 3 different families of complex carbohydrates and we can't treat them all the same:
- Starches can be found in starchy vegetables like peas, corn, lima beans and potatoes, dried beans, lentils and peas, in grains like oats, barley and rice. They have a low glycemic index and they are really healthy. With that said, they are optimal sources for carbs.
- Sugars can be found in natural sources like milk or fruit, or in processed ones like in sweets, beverages etc., and they have mostly a high glycemic index. It's always better to focus on the food types with natural sugars in, if you have low sugar and you need a snack to boost your energy.
- Fibers can be found only in plant foods so there are no fiber in animal products such as milk, eggs, meat, poultry, and fish. Sources of dietary fibers include beans and legumes, fruits and vegetables, whole grains (whole grain pasta, cereals, breads, nut). They have a low glycemic index, and together with the starches the highest quality carbs to consume.
So just limiting all carbohydrates, just because sugars that are found in processed foods are bad for our healthy is a complete joke as you can understand. At the same time, some of these low-carb diets seem to suggest that protein and fats can be eaten freely. But a diet that's very high in animal protein and contains no whole grain or not enough fruits and vegetables could leave us with serious problems in the long run. In fact, the category of carbohydrates includes a wide spectrum of foods. We aim consuming the ones with the low glycemic index, the ones which are really important for our health.
Whole grains like brown rice and rolled oats are carbohydrates that provide our bodies, and our brains more importantly, with a usable source of energy. In these foods significant amounts of fibers are also present. As I mentioned before, during digestion the carbs from such foods will be broken down in glucose. But in the same time, these foods contain fibers; will bind on glucose and slower down its release in the bloodstream. That's why you should eat food rich in carbs AND fibers.
Refined sugars that are found in white bread, white pasta, white rice, sweets or beverages, don't have any or only a few fibers inside. These types of foods have a high glycemic index, meaning that they will lead to a spike of insulin. Eating foods that are refined, especially highly processed carbohydrates, can result in an earlier return of hunger (as 2-3 hours after eating, all glucose is taken out of the bloodstream) and a tendency to eat more frequently (usually bigger quantities too), and in the long run creates the risk of developing obesity and/or diabetes type II.
For people who are struggling to eat healthier and/or to manage their weight, or their blood sugar levels, eating foods that have a low glycemic index is especially important. However, choosing low glycemic foods is generally a good idea for all us. So when we talk about dietary carbohydrates we're actually talking about a very broad family of foods. Some that can be harmful to our long term health, and some that can support it. Learning how to choose the right foods within each nutrient category is one of the keys to long term success.
The truth about dietary fats
For decades, the scientific community obsessed over the damage fats can cause to our health; should we worry about fat, should we worry about carbohydrates, which nutrient is worse to eat in big quantities? Big corporations bribed titans of science to shift the blame on fat instead of sugar. This change of focus on what is healthy, is very convinient for all corporations that produce snacks, sweets and beverages, low on fat but fuuuuull in sugar (high glycemic index, remember?). This war against fat led to an enormous increase in the availability of fat free and reduced fat foods. But in spite of this, obesity rates continue to rise. So, should we reconsider the guilty role offat per se (It's the the oversonsumption of sugar, that we have to blaim fellas!)?
Today, rising awareness about the difference between the so-called good fats and bad fats is absolutely vital. Dietary fats can be divided in two big families; the saturated and the unsaturated fats 9and one fake one; thans fats).
First there are the saturated fats. These fat molecules are saturated with hydrogen molecules, which means that they can lie flat (think of them like pencil structures), and pack together densely. Saturated fats tend to be solids at room temperature and can be found in animal fats, like lard and butter.
The second family consists of the (natural) unsaturated fats. These fat molecules are less saturated with hydrogen (than their saturated cousins), which doesn't let them to stay flat; they are like branches. This means that these fat molecules don't pack together as tightly, leaving most unsaturated fats in the liquid state at room temperature. They naturally exist in olive oil and others oils, flax seeds, chia seeds and hemp seeds, walnuts, mixed greens and nuts and avocado.
Omega 3 fatty acids are a special kind of unsaturated fatty acid, and they're found in high concentrations in fish oil, in nuts, flax seeds, and other vegetable oils. Omega-3 fatty acids are the only kind of fatty acid that the human body can't make, so they're essential for our health and they need to be consumed via the food we eat.
Trans fats are man-made unsaturated fats & they're not real unsaturated fats. They are chemically manipulated saturated fats into unsaturated ones. These are the fats found in some margarines and in deep frying oils used in almost all fast food restaurants. These ones are really nasty! Their structures are very unstable and they flip easily to the trans orientation, rather than a cis orientation (=the orientation of all natural chemical molecules in space). And this is where we get the name trans fats.
Trans fats are problematic for our health because they increase the amount of bad cholesterol (LDL cholesterol) in the blood and they lower the amount of good cholesterol (HDL cholesterol). By doing this trans fats promote to formation of arterial plaques and increase the risk of heart disease.
While saturated fats have also been shown to contribute to increases in bad cholesterol, they haven't been shown to lower good cholesterol or to contribute to the development of arterial plaques as significantly as trans fats.
So, what's the bottom line when it comes to foods that contain fat?
Probably the most sensible food recommendation is this. Enjoy reasonable amounts of foods that contain mostly naturally occurring unsaturated fats like those found in olive oil, nuts and avocados. Avoid all foods containing trans fats. And limit your intake of foods like red meats that are high in saturated fats.
The truth about dietary proteins
In general, animal sources of protein like fish and eggs provide all of the essential amino acids in high enough concentrations that these foods are called complete protein sources. We can always replace the red (beef) and white (pork, poultry) meat with fish. Fish is (especially the fatty ones: anchovies, sardines, herring, mackerel*) and other types of seafood are very important parts of a healthy diet; they are high in proteins and low in saturated fat, rich in omega-3 fats, Vitamin D and selenium.
In contrast, plant based protein sources like beans, lentils, nuts and tofu tend to be incomplete sources of protein. It might seem that since plant-based proteins are incomplete in their nutrient content that they're nutritionally inferior compared with animal-based proteins. But in fact the health benefits of substituting plant-based proteins for animal-based ones, ideally a few days a week, this far outweighs the risk of falling short on essential amino acids. Plant-based proteins can be combined with other foods to provide a complete amino acid profile. In fact, many traditional food combinations like corn and black beans or rice and lentils are based on the principal of combining complementary proteins
*: Salmon is also a fatty fish full in omega-3, but since in the last years the need for salmon is multiplied, fishing wild salmon is depleting the natural resources. Also many salmon farms feed the fish with steroids; so that they grow faster (consumption of extra steroids is considered carcinogenic).
+ Unsaturated Fats
- Unsaturated Fats
Your challenge from now on: The elements of a great meal
Let's talk about how the perfect meal can take from 10 minutes to as much you want to spend on it (no more excuses to go for “fast” food again).
- A great meal consists of: lots of vegetables, small portions of carbs with low glycemic index, plant or fish-derived proteins and unsaturated fats sources.
- Always start planning the meal from the point of view of vegetables; decide on the type of the vegetables you want to eat and the way you want to prepare them (in a salad, stir-fry, steamed, grilled?) Once you decided on your vegetables, pick a source of protein: plant proteins or meat proteins? Substitute the meat of your diet with fatty fish, nuts, seed and other plant-proteins. Approach the meat as the side dish and not as your main course. Protein done? Think about a source of complex carbohydrates; starches, fibers, or sugars. Or all of them? Always go for whole grains, don’t settle for processed versions (eg. brown rice instead of white, quinoa, whole grain bread instead of white).
- In the morning/afternoon add in your diet 1-2 servings of fresh fruit and nuts, instead of highly processed snacks and sweets.
- Try to prepare your meals with fresh and natural ingredients and try to stay away from frozen pre-made ingredients, which contain more than 5 ingredients.
So that's all! I hope I didn't burn you with information today. :D
I believe that if you understand and apply today's lesson, you will feel your diet swifting to a healthier one in a week or less friends.
Do you think you can implement some of these tips in your everyday cooking? Let me know if you have questions and/or if you want to discuss your progress.
Credits | Text & Photography: Despina Kortesidou, Τελευταίο γραφικό: Harvard Medial School