According to WHO statistics, about 5% of adults are underweight. The causes of this condition are different – from eating disorders to gastrointestinal diseases. We tell you how to determine underweight and solve the problem.
How is the weight norm calculated?
To assess the weight norm, a generally accepted indicator is used – the body mass index (BMI). It can be calculated using a simple formula.
A body mass index of less than 18.5 is considered underweight , and a BMI value of less than 16 corresponds to severe deficiency. For example, a girl who is 160 cm tall and weighs 50 kg has a BMI of 19.5 – this is normal, there is nothing to worry about. But a girl who is 178 cm tall and weighs 50 kg will have a body mass index of 15.7 – a pronounced weight deficiency.
At the same time, BMI is not an ideal indicator. For example, it does not take into account the ratio of fat and muscle tissue. Thus, a bodybuilder has a significantly higher sBMI than a person far from sports – due to muscle mass. It is important to focus on your own feelings: you can set a goal to gain weight, even if everything is fine with BMI. For example, for a girl with a height of 163 cm, a safe weight for health is from 50 to 66 kg, but at 50 kg there may be a desire to gain weight – and this is normal.
However, a decrease in BMI and a sharp weight loss of 15-20% of your usual weight over the past six months is a strong argument to go to the doctor and find out the cause of the deficiency.
Why does underweight occur?
It can develop if the body lacks nutrients and microelements. People who practice extreme diets with daily consumption of up to 600-800 calories are at risk. For comparison, according to experts, women over 30 with low and medium physical activity are recommended to consume from 1,800 to 2,000 calories per day. There are different versions of such diets: a diet consisting only of vegetable and fruit juices, excluding products with any natural sugars, eating only one product, such as grapefruit or soups. In this case, weight usually decreases not due to a decrease in fat deposits, but as a result of a sharp loss of fluid and muscle mass.
Doctors do not recommend resorting to such methods – it is simply dangerous. People with a high body mass index may be recommended diets with a restriction of total calorie intake. At the same time, a weight loss of 5-10% in six months is considered safe . For example, if a woman weighed 100 kg, then the optimal goal would be to lose 5-10 kg in 6 months.
In some cases, health problems interfere with the normal intake of nutrients and digestion of food:
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Oncological diseases and liver diseases. They cause loss of appetite, diarrhea and vomiting.
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Crohn’s disease: In people with this disease, immune cells attack the walls of the gastrointestinal tract, so nutrients are not absorbed.
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Chronic obstructive pulmonary disease. This disease causes the airways to become inflamed. As a result, inflammatory substances called cytokines are produced, which reduce appetite and lead to loss of muscle mass;
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HIV infection. When the virus attacks the gastrointestinal tract, it causes diarrhea, dehydration, and prevents the absorption of nutrients. In addition, the human immunodeficiency virus destroys immune cells. As immunity declines, the intestines become a habitat for dangerous bacteria, fungi, and viruses, which also causes diarrhea.
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Thyroid diseases. With an excess of thyroid hormones – thyrotoxicosis, metabolism increases , the breakdown of fat and proteins is stimulated, and body weight decreases.
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Mental illnesses. For example, underweight can develop in people with clinical depression, chronic stress and anxiety, dementia and eating disorders – bulimia and anorexia nervosa. In addition to apathy, anxiety and helplessness, there is often no appetite . Psychiatrists suggest that the risk of developing eating disorders may be higher in people with traumatic childhood experiences.
In addition, weight loss problems are common in patients who are forced to undergo long-term hospital treatment. In this case, malnutrition can be caused by limited movement, depressed mood, and side effects of therapy. For example, nausea, vomiting, and loss of appetite are not uncommon during chemotherapy treatment.
The dangers of being underweight
This condition threatens the loss of not only fat but also muscle mass. As a result, muscle atrophy may develop, which is accompanied by general weakness, unexplained pain and rapid fatigue. In addition, people with a weight deficit have poorer wound healing and a high risk of surgical complications. In women, the menstrual cycle and maturation of eggs are disrupted . Lack of weight also affects the nervous system: the risk of depression , sleep disorders and strokes at a young age increases.
When the body lacks microelements and nutrients, it has a harder time coping with many functions. For example, immunity is reduced: people become vulnerable to infections, atopic dermatitis or autoimmune diseases may develop. The ability of the immune system to protect the body from malignant cells also suffers. For example, weight deficiency is associated with a worse prognosis for patients with stomach cancer after surgery, and a low body mass index in women correlates with an increased risk of breast cancer.
How to gain weight
The first thing to do is to see a doctor and make sure there are no health problems. The next step is to ensure you have enough calories. The daily calorie requirement is individual and depends on age, height, weight, and physical activity. You can discuss this with a nutritionist or calculate the calorie requirement yourself, for example, using the Harris-Benedict formula for women:
The resulting figure must be multiplied by a coefficient that reflects the level of daily activity:
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If the work is sedentary and there is no physical activity during the day, the coefficient will be 1.2.
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When training 3-5 times a week, the coefficient is 1.55.
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If you train 6-7 times a week, the coefficient is 1.725.
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For those who lead a very active life or do heavy physical labor, the number of calories needed should be multiplied by 1.9.
For example, a girl who is 165 cm tall and weighs 65 kg, who works remotely and only goes out for a walk on weekends, needs about 1,740 kcal per day. And a professional athlete with the same parameters may need 2,500 kcal.
People with a weight deficit need from 300 to 500 additional calories per day. It is important to create a balanced diet: add foods with a high protein content, dairy products, complex carbohydrates.
Here are some tips to help you gain weight without risking your health:
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Gain weight gradually . Eat small portions, adding healthy snacks between breakfast, lunch and dinner. You can have 5-6 meals a day . If you have no appetite, you need to plan your time so as not to forget to eat.
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Add high-calorie drinks to your diet. For example, try drinking milkshakes as a snack.
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Maintain a balanced diet. The classic “Harvard plate rule” states that a quarter of the plate should be proteins, a quarter fats and carbohydrates, and half vegetables, fruits and vegetable oils. Give preference to whole grain pasta, bread and cereals, dairy products, fish, meat, eggs, legumes, nuts and seeds. Do not refuse fresh fruits and vegetables. They contain essential vitamins and microelements, as well as fiber, which is necessary for stable bowel function.
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Remember about protein. This is the main building material for all body tissues. The daily requirement for protein is 0.8 g per kilogram of body weight, and with each meal you need to consume 15-30 g of protein. So, a woman weighing 68 kg needs 54 g of protein every day: this is, for example , 25 g of baked fish, a couple of chicken eggs, a cup of plain yogurt and 30 g of cheese. To increase the amount of protein in your diet, you should pay attention to dishes with beans, legumes, fish, eggs and lean meat, and you can add pumpkin and sunflower seeds, walnuts and peanuts to salads, yogurts and porridges.
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Do strength training. Basic exercises with your own weight are useful : squats, planks, lunges, crunches for the abdominal muscles, push-ups. It is important that the exercises are regular; 3 sessions a week are enough for beginners. Do not forget about basic physical activity. WHO recommends at least 2-3 hours of moderate physical activity per week. If the gym and fitness are not your thing, regular walks, cycling, swimming, rollerblading or skating will do . A nice bonus – exercise improves appetite.
What mistakes can be made when gaining weight
The golden rule in any business is that everything is good in moderation:
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Don’t chase quick results . Building muscle mass quickly by relying on protein products and protein shakes is a dubious idea. For people with kidney disease, excess protein in the diet can be harmful .
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It is dangerous to abuse products containing saturated fats. These include, for example, chocolate, butter, pastries, cakes, and highly processed foods. They increase the level of cholesterol in the blood and increase the risk of cardiovascular diseases. Excess sweets can lead to insulin resistance and diabetes.
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It is important to monitor your water balance. But it is better not to drink right before eating – this can reduce your appetite.