Diet or Lifestyle? 1.1. Diets and their impact on health & which diet is for whom.
- Body mass index
- What is dangerous about being overweight
- Different types of diets: Low carb diets (Atkins diet, Keto diet, Dukan diet)
The word “diet" in Greek means “lifestyle". However, today the word “diet" usually refers to a special diet – for people with certain diseases, and – even more often – it means a diet for weight loss.BMI stands for Body Mass Index Body Mass Index
(BMI) considered to be one of the indicators of a healthy weight, which is calculated as the ratio: weight (kg)/ height (m2). Normal body weight corresponds to BMI (kg/m²) = 18.5 – 24.9 (for the Caucasian population), while BMI between 25 kg/m² and 29.9 kg/m² is considered overweight and BMI of 30 kg/m² or higher is considered obese.
Sufficient to say that even normal body mass index is not an ideal indicator of healthy weight (or general health), since it does not reflect the body composition. A more accurate understanding of body composition (the percentage of body fat and muscle mass in the body) can be obtained by bioimpedance analysis (BIA, also known as bioelectrical impedance analysis or body mass analysis).
The waist circumference (WC), as well as the BMI, is an important indicator of health. It should not exceed 80 cm for women and 94 cm for men. According to the WHO, the WC > 94 cm in men and > 80 cm in women (for Caucasians) is associated with an increased risk of metabolic complications and Metabolic Syndrome (MS) as it indicates the presence of abdominal obesity (the type of obesity in which fat is deposited in the abdominal area).
Metabolic syndrome (syndrome X, insulin resistance syndrome) is a symptom complex characterized by abdominal obesity, impaired glucose tolerance, and impaired lipid and carbohydrate metabolism, and arterial hypertension.
WHO experts consider the metabolic syndrome a " pandemic of the XXI century", its prevalence in developed countries is about 20-40%.
According to the results of the studies, on average, 26% of the adult population of the planet has a metabolic syndrome; most often it occurs in middle-aged and older people (30-40%).
Abdominal obesity is the main criterion for metabolic syndrome (MS).
Additional criteria for MS include an increase in the blood pressure level over 140/90 mm Hg,
dyslipidemia, impaired glucose tolerance, impaired fasting glycemia, etc.Is excess weight dangerous?
Yes – it not only leads to diseases, but also reduces our chances of longevity.The most common health consequences of being overweight and obese
Increased BMI is a major risk factor for noncommunicable diseases that contribute to premature aging and death: cardiovascular diseases (mainly heart disease and stroke), which are a major cause of death; diabetes; disorders of the musculoskeletal system (especially osteoarthritis-a disabling degenerative joint disease); certain cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon cancers). The risk of these noncommunicable diseases increases as the BMI increases.What strategies are available for weight loss? Non-pharmacological therapies
• Dietary modifications – principles of healthy eating, reducing the caloric content of the diet, drinking regime.
• Lifestyle modifications – daily routine, physical activity, healthy sleep.
• Psychotherapy, behavioral therapy.Pharmacological therapy
• Anti-obesity medicationsSurgical therapy How to reduce excess weight?
Following the principles of healthy eating while reducing the caloric content of the diet or increasing physical activity is enough to reduce weight. However, in the pursuit of a quick result, many people start trying not only" magic " dietary supplements, but also various (fad) diets, forgetting that compliance with restrictive diets can contribute to various health problems, both in the short and long terms.
Let's take a look at some popular diets for weight loss, their features and impact on healthLow-carb diets:
• Low-carb high-Fat diets (Atkins, Keto diet, LCHF)
• Low-carb high-Protein diets (Dukan diet)Low-fat diets (Ornish) Paleo diet
The Atkins diet
This is a classic low-carb diet for weight loss, which was developed by Dr. Atkins in the 60s of the 20th century. This diet has evolved over time. If initially its compliance meant the consumption of unlimited amounts of fat – butter, bacon, fatty meat, etc., then more modern versions of the diet already pay attention to the importance of eating vegetables and sufficient protein, while limiting simple carbohydrates. At the 1st stage, the amount of carbohydrates (which must be obtained from green leafy vegetables) is minimal-20 g / day. In the future, it is recommended to increase the amount of carbohydrates to 100 g/ day (this is the maximum official allowed amount). Features
of the diet – excess of fat (as well as protein) and restriction of carbohydrates (especially in the initial stages) may lead to a rapid weight loss. Possible problems with the Atkins diet are insufficient fiber, lack of vitamins, chemical elements, excess of protein and fat, including saturated fats. There may also be problems with the gastrointestinal tract (in particular, nausea, constipation) and the cardiovascular system, impaired kidney function, headaches, fatigue.
In recent years, the diet recommends the use of bars and other products of the “Atkins program", which belong to the products of deep processing and can hardly be considered a healthy diet. The Keto diet
It was originally developed in the 20s of the 20th century for the treatment of epilepsy in children, and was carried out exclusively under medical supervision. A true keto diet is an extremely low-carb, high-fat diet – the amount of carbohydrates is less than 20 g per day. During the diet, the body enters a state of * ketosis and begins to use fats (instead of carbohydrates) as fuel for energy. Against the background of ketosis, the frequency and severity of epilepsy attacks decrease in patients. A true ketogenic diet in which the body goes into a state of ketosis: fat is 75% – 90% of calories, protein is 10% – 20%, and only 5% is carbohydrates. Features
of the diet – extremely low levels of carbohydrates, which can lead to rapid weight loss. To be sure that you follow the ketogenic diet (and your body is in the state of ketosis), it is necessary to monitor the level of ketones in the blood or urine, using special test systems. Long – term consequences of keto diet compliance in people (without epilepsy) are not well understood. There is an evidence of the microbiome alterations and the development of insulin resistance with a long-term (more than 1 –2 years) diet compliance. Side effects of the diet include “keto flu", weakness, muscle pain and constipation due to the lack or very small amount of fiber. Possible problems may include alterations of the digestive tract (nausea, vomiting due to excess of fats in the diet, especially in case of the liver and gall bladder diseases) and headaches; moreover, long-term adherence to the diet may be difficult in case of visiting social events.
*Ketosis is a condition that develops as a result of carbohydrate starvation of cells, in which the body (in the absence of carbohydrates in the diet) begins to break down fat with the formation of a large number of ketone bodies. Ketosis is one of the adaptive responses to the lack of carbohydrates in food. The meaning of ketosis from the evolution point of view is to allow the body to survive in the shortage of carbohydrate-rich (plant) food, switching to food rich in fats (this is primarily animal food). Author's note. Fortunately, most people who think they follow a ketogenic diet don't actually follow it and just stick to a (relatively) low-carb diet. The Dukan Diet
The diet was developed by Dr. Dukan, it includes 4 phases and refers to restrictive diets. At the 1st stage of the diet, it is allowed to eat only low-fat protein products, water and non-calorie beverages, and 1.5 tsp. oat bran; from the 2nd phase of the diet, it is allowed to add non-starchy vegetables to the diet. In the future, it is recommended to add a variety of vegetables, cereals, fruits, and fats to the diet. Features of the diet.
Rapid weight loss (especially at the initial stage) is possible, because protein provides a high level of saturation. From the last stage of the diet, which should be followed for life, it is recommended to use oat bran daily, it is also necessary to arrange an “unloading" day with the use of low-fat protein products weekly. At least 20-30 minutes of physical activity per day is also recommended. The diet puts a lot of emphasis on protein products, calling fats and carbohydrates “enemies" of the body.
Possible problems with the Dukan diet may include a lack of vitamins and chemical elements. Also, the diet is contraindicated if you are predisposed to the formation of kidney stones or if they are present, health problems may appear in the presence of the gastrointestinal tract diseases (nausea, constipation in particular), headaches, fatigue. If there is a predisposition to gout, it may appear (or worsen – if it exists) against the background of compliance with this diet. Low Carb Diets
It should be noted that there are many varieties of low-carb diets, and they are a heterogeneous group. The same name – “low-carb diet" – unites different diets that include from 20 to 150 (!) grams of carbohydrates per day. As we can see the percentage of carbohydrates in different low-carb diets can vary from 4-5% to 30% of calories (based on a diet of apprx. 2000 kcal). Accordingly, this further complicates the task of those specialists who are trying to assess the impact of a low-carb type diet on human health. Advantages and disadvantages of low-carb diets.
A number of studies has shown that low-carb diets can initially provide faster weight loss, and can also improve glucose levels and – in part – lipid profile – in patients with type 2 diabetes and insulin resistance. However, in the long run, these benefits do not persist when compared with other diets. Adherence to low-carb diets may be accompanied by the risk of developing vitamins and minerals' deficiencies, the appearance or exacerbation of various somatic and endocrine diseases. In addition, there are not enough long-term observations of large groups of people on a low-carb diet, and there is no data from RCTs (randomized clinical trials) that would show the benefits of this type of diet and its safety for human health. To be continued…