Contents
About the rules on different essential substances — vitamins and minerals — we have heard many times. Probably each of us took vitamins at some period of life. These substances are called “micronutrients” because their number is extremely small compared to the amount of food, and there is no considerable fraction of the mass of meal or the energy balance of the body. But how are things with the “macronutrients” — proteins, fats, and carbs? Are there any “optimal” values for these nutrients? Is there a mandatory minimum or maximum? Is there anything good or bad to “overeat” carbs? “Malnourished” fat?
Surprisingly, with the exception of the required minimum standards of protein and essential amino acids, and two types of essential fats, and all other values of consumption of the macronutrients, are currently under-researched area of knowledge about nutrition, causing serious disputes. To date, official science is unable to recommend a specific optimal for everyone ratio of P/C/F. Any numbers you have met in the literature can be either private recommendation or average statistically given size and for different people, they may be acceptable in varying degrees. By far the only concept is caloric — that is, the total energy balance determines how in the long term changes the weight, almost regardless of the proportions of the individual components of the diet. Below we will tell about the main points related to the amount and type of different macronutrients, and give some rules that exist in the world. Those who are only interested in the summary findings and numbers, can skip to the end.
Proteins
Undoubtedly, protein is the most important of the macronutrients. If no significant damage to the health of a person can be caused by almost no carbs or no fats (with little exceptions), the absence in the diet of adequate amounts of protein for a few weeks, sometimes days, is a blow to all systems of the body, including those that will immediately be noticeable on the functioning of the immune system, composition of blood, skin quality, the processes of healing/recovery.
Minimum standards for the consumption of total protein and individual amino acids were determined. For a long time, they took the form of mandatory rules in all countries and at the international level. In most countries, they amount to 0.8-1 g of protein per kilogram of body weight, provided that the usefulness of the protein (in different forms is defined differently). In standards of our country full protein diet is considered the one, in which at least 50% of the protein comes from animal sources.
But as for the upper limit of protein intake, there is still no certainty. The rules for a safe range of protein use referred to as 100-160% of normal. The WHO concludes that at least twice the amount of protein relative to the norm is safe. In American standards, an acceptable protein intake is considered in the range of 10-35% of energy consumption (assuming a good diet).
Numerous studies show that a large number of people are consuming proteins in quantities of more than 2 g/kg without any harmful effects. On the other hand, in cases of renal failure or disorders in the digestive tract excessive amounts of protein can harm the body. It’s important to know for those involved in bodybuilding and other strength exercises, because despite the fact that the experiments proved that intake of protein more than 2G/kg did not improve muscle growth and athletic performance (and in non-violent sports more than 1.5 g/kg), a very popular belief that “the more you eat protein, the more muscle will grow”.
There is a separate study about the bad effect of large amounts of protein consumption for the kidneys, the growth, and maintenance of healthy bones, kidney stones, and cardiovascular disease. But most of the results are still quite controversial and no definitive generalizations at the moment can be done, at least within the above ranges.
But it is necessary to remember about providing the body with plenty of water while consuming a lot of protein: unlike other macronutrients, the protein can not be burned fully by the body, so unused nitrogen is bound in urea and excreted from the blood through the kidneys, and this process requires a considerable amount of water.
Also, not all people can absorb a large amount of protein. For someone it is easy to eat 200-300 g protein a day, some people badly digest even 150 grams. There are reports that partially, the ability to digest large quantities of protein is predetermined genetically, and for some of the Northern peoples – more than 99% of the population easily tolerates huge by modern standards, daily amounts of protein.
With regard to the use of diets high in protein for weight loss, such diets have proven two positive points:
- Proteins — the “saturating” macronutrient. It provides the longest satiety, and provides the highest “thermic effect”.
- Proteins, in increased share in the energy-deficient diet, help to preserve muscle mass during weight loss.
So many weight loss methods are using a diet with a high percentage of protein as the most comfortable, or even more “effective” for weight loss. Although the exact experiments show that the main case is still in calories, satiety, and maintaining muscle, obviously, the most important factors that indirectly affect the long-term effectiveness of the diet.
Also, there is a popular diet in which protein can be eaten in unlimited quantities, and you can’t eat almost anything else. These diets really work, because the maximum daily amount of protein that can process the liver and kidneys, is 250-400 g, which is obviously less than your daily calorie norm (2000 – 3000 kcal).
However, for those who are trying to live on such a diet, it’s helpful to know about the symptoms of protein poisoning and to monitor the health of their own kidneys. What’s funny that protein poisoning in English is often called “rabbit starvation”. It was first described in North American Indians who were forced in some periods of life to just low-fat meat of rabbits. If during the week they couldn’t find any more fat or carbohydrate food, they were persecuted, diarrhea, headache, weakness, and uncontrollable hunger.
Therefore, determining your diet, keep in mind all of the above and pick what suits you.
Fats
The problem of adequate consumption of fat breaks down into several separate questions:
- Providing essential fatty acids (omega-6 and omega-3).
- The provision of adequate digestion
- Optimization of risks of various potential diseases.
Let’s start with the fact that some fats (omega-6 and omega-3) are essential, the body can not synthesize them by itself and must obtain them from food. Despite this fact is definitely proven, the precise magnitude of human needs in these nutrients is not established, recommended by the WHO norm is low enough (AI — Adequate Intake) for omega-3 is 0.5%, calorie content (hereinafter referred to everywhere, if not stated otherwise, percentages mean proportion of total energy intake) for omega-6 2.5%. Serious failure typically occurs when consumption is several times smaller, and the deficiency of omega-6 is reflected, first and foremost, in the skin and liver, and omega-3 in neurological symptoms.
Different countries have slightly different values for the allowable minimums, but, as will be discussed further, the excess of these quantities is very useful, and is therefore usually set a certain recommended range.
From the point of view of influence on digestion, fats promote absorption of fat-soluble vitamins, as well as slowing the movement of food through the digestive tract, which improves the absorption of indigestible food. To lower the amount of fat below 20% is dangerous because it creates a risk of poor absorption of other nutrients and lacks the indispensable fatty acids .
Let us turn to the physiological action of various fats and their impact on different risks.
From the standpoint of reduction of blood cholesterol, especially LDL, it is useful to reduce the amount of saturated and TRANS fats in food. In contemporary international norms is specified as the maximum allowable, 10% saturated and 1% TRANS fat, but right is recommended, if possible, to reduce their number within to maintain a balanced diet.
While polyunsaturated fatty acids significantly reduce the amount of LDL and increase HDL. Subject to the restrictions, which will be discussed below, it is recommended to increase their share in the diet. Polyunsaturated omega-3 reduces the formation of thrombus, so the increase in their share is also considered useful in the context of reducing CVD.
But restrictions on the maximum number of polyunsaturated fats, especially omega 3, are much more strong. Polyunsaturated fats when consumed in excessive quantities, lead to the strengthening of the process of lipid peroxidation, which destroys cell membranes. Especially compounding the situation is the deficiency of vitamin E. the Maximum amount currently permitted by international standards is 9% for omega-6 and 2% to omega-3 in the form of alpha-linolenic acid (remember, this is the “vegetable” omega-3 from Flaxseed and soybean oil, walnuts, etc.). Additionally allowed up to 2g (according to the norms of USA and some other countries up to 3 g) “long-chain” omega-3 (omega-3 from oily fish, DHA+EPA, docosahexaenoic+eicosapentaenoic acid).
Except all above, for healthy individuals, modern science has no basis for recommendations of any specific quantity of fat in the diet. WHO and most countries settle for fat as acceptable, the range of 20-35% of total daily energy. But for a particular person may be recommended the other values, if this ensures the usefulness of the diet and its safety.
Briefly about the importance of fats for losing weight. Experiments have proven that for weight loss the amount of fat in the diet has no value, just calories. Very often, problems with skin, liver, and female reproductive organs are slimming, unknowingly, reduce fat intake to almost zero, considering that it will positively affect their own fat. It’s a very harmful delusion, dietary fat is not “automatically go to the sides”, and a similar lack of fat is unacceptable!
For men, it can be important that a greater amount of fat in the diet increases testosterone levels, which indirectly, through the impact on activity and muscle mass in the long term contributes to both weight loss and other changes.
And for all losing weight people is also helpful to know that adding fat to food, particularly protein, prolongs the feeling of satiety by slowing down the movement of food through the digestive tract.
Carbohydrates
Carbohydrates are the main source of energy for most people, but the consumption of them by different people is very different. This concept of “essential”, as in the case of proteins (essential amino acids) or fats (essential fatty acids), in the case of carbohydrates, are there. There is no minimum level of total carbohydrates or specific type. There is no norm consumption less than which would be dangerous to the health of most people.
However, to ensure the daily needs (primarily, brain), the body requires about 100g of glucose which normally comes from the carbohydrates and glycogen of the liver. Prolonged inadequate consumption of carbohydrate food, leads to the case when glucose is produced in the liver from proteins in the process of gluconeogenesis, as well as partially used glucose instead of ketone bodies.
This process differently tolerated by different people, some people hardly notice the lack of carbs in the diet, and some are experiencing significant discomfort, until “acetone” smell emanating from people when ketosis. Therefore, by many standards, it’s not recommended to reduce carbohydrate intake below the value of about 100g, although most people have no problems with excessive protein intake some has with lower carbohydrates.
But in the case of carbohydrates, there is another, probably the main problem, and it’s called “sugar”. More precisely, the sugar glucose and sucrose, in the first place. Man is poorly adapted to the consumption of pure sugars, and the modern wave of diabetes and other metabolic disorders (insulin resistance, obesity, metabolic syndrome), which covered the Western world (Yes, and not only), most scientists associated primarily with increased amounts of refined sugars in the diet.
While there is some difficulty in the guidance of norms. Directly above the metabolic result of fast absorption carbohydrates (absorption speed is expressed numerically on the glycemic index — GI), and it is not always directly related to the type of carbohydrate consumed. If to fry the potatoes for a long time, or to tenderize pasta – they will, due to the thermal modification, have a much worse GI than the sugar contained in carrots or apples, although, formally, the starch in the potatoes is considered “slow” carbohydrate, but fructose, glucose and sucrose in apples are considered “fast” carbohydrates.
But then again, if from one of these carrots or apples to squeeze out the juice, then in the sense of the attack on the insulin system, such sugar will not be much different from sweet drinks. In this context, sometimes with classification share of the so-called “external” and “internal” sugar, i.e., separately consider dissolved in food and is hidden behind cell walls. But the lactose in milk is also one of the types of dissolved sugars, but its GI is so low that it is safe, despite the fact that, formally, according to the classification it belongs to sugars and dissolved.
So the advice is — do not rejoice at the indication that the product has no added sugar. It may be their own sugar in an easily accessible form (raisins, dates, honey) or digestible starch, modified by heat treatment (fried potatoes, chips, pastries). Remember that natural fruit juice for fat kids pediatricians equate risk to Coca-Cola. If you have reason to fear simple carbs (pre-diabetes, MS, or obesity), don’t look at the composition and GI of the product.
However, we should mention that according to different recommendations, the percentage of added sugars should not be more than 5…20% of the energy in the diet. The rules often limit the consumption of added sugars to a value of 10%. The WHO says about 10%, which include “foreign non-milk sugar”, is true given that dissolved any sugar except lactose is as dangerous as high GI.
This is especially true for people addicted to sugar: they often think that by replacing sugar and candy on dates and honey or drinking instead of Cola the fresh juice. They avoid the harm from sugar. Of course, it is self-deception: contrary to the ad in the “natural foods” or in women’s magazines, sugar is bad not the fact that it is “chemically” refined, and the fact that it has a very high GI.
Therefore, brown sugar is harmful exactly the same as white, and honey or dates have gone not far from him. But if it’s juice or broth, we get approximately the same refined sugar (the essence of the refining of dissolving the sugar by boiling). Therefore, despite the fact that there are no such clear rules on the carbs, there is a clear recommendation to reduce the GI of carbohydrate foods, especially if the person has the appropriate risks (all people with a BMI>25). For losing weight is also important to know that foods with a high glycemic index provoke subsequent appetite and overeating.
Carbohydrates also include fiber (dietary fiber). There are different types, now we will not consider them in detail. We remind you that for the most part it is not digested, but helps to correct the bowel. It is advisable to consume normal fiber, particularly with a low-calorie diet, containing a small amount of food. In addition to improving peristalsis and prevent constipation, there are data on the correlation of fiber intake with a reduction of bowel cancer. As is the case with many nutrients, the tolerance to a large number of fat is very different between people. However, there is no evidence of any benefit of consuming large quantities of fiber, and very large quantities can impair digestion.
A brief summary and conclusions.
From the strict restrictions, it is important only to mandatory follow the consumption norms of protein (and separately each of the essential amino acids) and two essential types of fatty acids — omega-6 and omega-3. The rest is a matter open to arbitrary choice in a wide range.
Proteins. Consume not less than the norm. More — the condition of the body and on the advice of doctors or trainers. Russian recommendations — 100-160% of normal, American — 10-35% of calories (subject to the usefulness of the diet), the WHO considers safe up to 200% of normal protein.
You should also obtain all the essential amino acids. If you primarily consume the protein of animal origin, then you get it automatically. If you are vegan, then properly balance amino acids composition. Standards require at least 50% to obtain protein from animal sources, it guarantees a sufficient supply of all amino acids.
It is important for losing weight: increase the proportion of protein gives some advantages for weight loss in the sense of increasing satiety and reducing the loss of muscle mass. But even athletes have no benefit from protein of more than 2G/kg, and the additional load on the liver and kidneys are the significant.
Fats. The total number of it is desirable to maintain in the range of 20-35% of daily energy. A significant excess proportion of fat may be undesirable because of the increased consumption of saturated fats and inadequate intake lead to impaired absorption of other nutrients and deficiency of essential fatty acids.
You must obtain all the essential fatty acids (omega-6 and omega-3). Standard consumption: 8-10 g/day of ω-6 and 0.8-1.6 g/day of ω-3. However, it is useful to obtain not minimum rate, and much larger, this reduces the risk of heart disease and blood vessels. If your diet has a large proportion of vegetable and fish fats, you can be sure that the essential fats you are getting enough.
Because in small amounts ω-6 and ω-3 are contained in almost all dietary fats, if you eat a lot of fat, the problem of insufficient essential fats are also not threatened. Ranges recommended by WHO: ω-6 — about 2.5-9% (5…20g for a diet of 2000 kcal), ω-3 — 0,5…2%E (1…4 g of plants + up to 2 g of fish for a 2000 kcal-diet). Excess consumption of these “healthy fats” is also dangerous, but if you do not drink Flaxseed oil or fish oil specifically, it will be difficult to over limit.
Saturated and TRANS fats are desirable to consume as low as possible, the maximum rate: saturated FA not more than 10%, TRANS fat not more than 1%. Saturated fats are found primarily in animal fats and solid vegetable fats. TRANS fats come to us from a special pastry and Margarine and frying fats.
It is important for dieters: fats slow down the movement of food through the digestive tract, which prolongs the feeling of satiety. This is especially noticeable on high-protein foods. It is also important to know that diets with a very small amount of fat is harmful, and that the amount of fat in the diet does not affect weight loss.
Carbohydrates. It is advisable to reduce their number to less than 100 g, which usually occurs under a normal diet. But in most cases, even less can be safe, consult your doctor or trainer, and get your personal recommendation. It is desirable to lower high-GI carbohydrate foods. Added sugars it is advisable to consume no more than 10% of caloric intake, and in general, the less — the better. Do not forget also that natural products can contain a lot of easily digestible sugar, which is no less harmful than added sugar.
The fiber is preferable to consume not less than the established norm.
It is important for losing weight: the higher the GI (quick absorption) of carbohydrate, the more they lead to subsequent improvement of appetite, sense of hunger and potential overeating. Therefore for energy-deficient diets it is particularly desirable to lower GI foods, or at least reduce one-time amount of fast carbs. Also with a small amount of food of special importance is the adequate intake of dietary fiber.