It is harmful to your health to be underweight. If you’re worried about yourself or someone else, find out what you can do. Weighing too little can lead to a compromised immune system, brittle bones, and exhaustion. You may find out if you’re underweight by using our BMI healthy weight calculator, which calculates your BMI (BMI). If your BMI is less than 18.5, your weight is probably too low. Tell your doctor or practice nurse if you’re underweight or concerned about someone you know. They can assist and advise you.
Body Mass Index (BMI) is calculated by dividing the square height by the mass in kilograms (kg):
BMI(kg/m2) = mass(kg) / height2(m)
BMI (Body Mass Index) in kilograms per square meter is equal to the mass in pounds (lbs) divided by the height squared in inches (in) times 703:
BMI(kg/m2) = mass(lb) / height2(in) × 703
BMI Chart for a 16 stone person:
The BMI is commonly used to determine how far a person’s body weight deviates from what is considered normal or acceptable for their height. Body fat (adipose tissue) may account for some of the weight surplus or deficiency, but other characteristics such as muscularity also have a substantial impact on BMI (see discussion below and overweight).
A BMI of less than 18.5 is considered underweight by the WHO and may suggest malnutrition, an eating disorder, or other health issues, whereas a BMI of 25 or more is considered overweight, and a BMI of greater than 30 is considered obese. These BMI ranges are solely useful as statistical classifications.
|BMI Category||BMI Range|
|Underweight||18.4 and below||Malnutrition risk|
|Normal weight||18.5 – 24.9||Low risk|
|Overweight||25 – 29.9||Enchanced risk|
|Moderately obese||30 – 34.9||Medium risk|
|Severely obese||35 – 39.9||High risk|
|Very severely obese||40 and above||Very high risk|
BMIs below 20 and above 25 have been linked to an increased risk of all-cause death, with the risk increasing as one moves away from the 20–25 range.
Is a BMI of 16 considered low?
A BMI of less than 18.5 is considered underweight and can have health implications, just as a BMI of greater than 18.5 is considered obese. If your BMI is 16, consult your doctor because it is dangerously low.
What is a BMI of extremely underweight?
Severely underweight – BMI less than 16.5 kg/m2. Underweight – BMI less than 18.5 kg/m2. Normal weight – BMI between 18.5 and 24.9 kg/m2. Overweight – BMI between 25 and 29.9 kg/m2. Obesity – BMI greater than or equal to 30 kg/m2.
What’s a good way to gain weight if I’m underweight?
Although being thin might be beneficial, being underweight can be dangerous if it is caused by poor nutrition, or if you are pregnant or have other health issues. So, if you’re underweight, make an appointment with your doctor or a dietitian. You can work out a strategy to reach your target weight together.
When you’re underweight, here are some healthy strategies to gain weight:
- Increase your eating frequency. You may feel fuller sooner if you’re underweight. Instead of two or three substantial meals throughout the day, eat five to six smaller meals.
- Consume nutrient-dense foods. Choose whole-grain bread, pasta, and cereals, fruits and vegetables, dairy products, lean protein sources, and nuts and seeds as part of a balanced diet.
- Try smoothies and shakes. Don’t overindulge in diet Coke, coffee, or other low-calorie, low-nutrient beverages. Instead, drink milk and fresh or frozen fruit smoothies or nutritious shakes with ground flaxseed sprinkled on top. A liquid meal replacement may be indicated in rare instances.
- When you drink, be cautious. Some people find that drinking fluids before meals makes them feel less hungry. In that situation, drinking higher-calorie beverages with a meal or snack may be preferable. Others may benefit from drinking 30 minutes after a meal rather than during it.
- Make every bite count. Nuts, peanut butter, cheese, dried fruits, and avocados are good snacks. Make a peanut butter and jelly sandwich or a wrap sandwich with avocado, cut vegetables, and lean meat or cheese for a bedtime snack.
- Top it off. Add more calories to your dishes by adding cheese to casseroles and scrambled eggs, as well as fat-free dried milk to soups and stews.
- Have an occasional treat. Even if you’re underweight, extra sugar and fat should be avoided. A slice of pie with ice cream on sometimes is OK. However, the majority of treats should be nutritious as well as calorie-dense. Good options include bran muffins, yogurt, and granola bars.
- Exercise. Strength exercise, in particular, can help you gain weight by strengthening your muscles. Exercise might increase your hunger.