BMI <17.0: moderate and severe thinness. BMI <18.5: underweight. BMI 18.5–24.9: normal weight. BMI ≥25.0: overweight.
below 18.5 – you're in the underweight range. between 18.5 and 24.9 – you're in the healthy weight range. between 25 and 29.9 – you're in the overweight range. 30 or over – you're in the obese range.
Your body mass index, or BMI, is the relationship between your weight and your height. A BMI of 20-25 is ideal; 25-30 is overweight and over 30 is obese. If your BMI is under 18.5, you're considered underweight. If your BMI is 18.5-20, you're a bit underweight and can't afford to lose more.
If your BMI is: under 18.5kg/m2 – you are considered underweight and possibly malnourished. 18.5 to 24.9kg/m2 – you are within a healthy weight range for young and middle-aged adults. 25.0 to 29.9kg/m2 – you are considered overweight.
If your BMI is below 20: Under Weight
If you are not an athlete, a lean BMI can indicate that your weight may be too low, which may lower your immunity. If your BMI and body weight are low, you should consider gaining weight through good diet and exercise habits, to increase your muscle mass.
Can a low BMI affect my fertility? Yes. Having a BMI below 18.5 is classed as underweight, which can make it harder to get pregnant. Having a low BMI can also cause your periods to become irregular or stop.
A normal BMI for an adult is 18.5-25. Above that you are overweight and below that you are underweight. Adults with anorexia have a BMI below 17.5. If you are under 18 years of age, normal weight is assessed by using special age-related BMI charts.
In males, a BMI of around 13 appears to be fatal. The coefficient of variation (CV) of the BMI is 8.7%. In contrast, females survive to a lower BMI of around 11, although with greater index variability (CV 14%). Several females had BMI's as low as 9 and 10.
for hospitalization:
BMI < 13 is an indicatior for certification under the Mental Health Act if the patient refuses admission although BMI < 13 alone is not enough for admission.
Being small, or even underweight according to the numbers, doesn't mean you need to gain weight. A healthy weight isn't necessarily “seen” and not a sign that something is wrong or that a person has an eating disorder.
Infrequent Periods
The greater your BMI (particularly in the obese range over 35), the more likely you are to miss your period. It is even possible to stop bleeding altogether, a condition known as secondary amenorrhea.
To interpret the final number, a BMI: below 18.5 means a person is underweight. between 18.5 and 24.9 means a person is of a “normal,” or healthy, weight. between 25 and 29.9 indicates a person is overweight.
Severely underweight - BMI less than 16.5kg/m^2. Underweight - BMI under 18.5 kg/m^2. Normal weight - BMI greater than or equal to 18.5 to 24.9 kg/m^2. Overweight – BMI greater than or equal to 25 to 29.9 kg/m^2. Obesity – BMI greater than or equal to 30 kg/m^2.
The best measure of whether you are a healthy weight is the body mass index (BMI). This is calculated using your weight and your height. In adults, a healthy weight range is a BMI of 18.5 to 24.9. If your BMI is under 18.5 then you would be considered underweight.
You could be malnourished if: you unintentionally lose 5 to 10% of your body weight within 3 to 6 months. your body mass index (BMI) is under 18.5 (although a person with a BMI under 20 could also be at risk) – use the BMI calculator to work out your BMI.
If your BMI is less than 18.5, it falls within the underweight range.
People who start adulthood with a body mass index (BMI) in the normal range and move later in life to being overweight -- but never obese -- tend to live the longest, a new study suggests.
BMI weight ranges
below 18.5 is underweight. between 18.5 and 24.9 is healthy. between 25 and 29.9 is overweight. of 30 or over is obese.
When looking at average BMI, three countries tie for the least obese country in the world, with an average BMI of 21.1: Madagascar, Eritrea, and Ethiopia.
People who are underweight or undernourished often experience symptoms such as fatigue and lethargy as well as low blood pressure, heart rate and blood sugar levels, which can cause night sweats, having cold fingers and toes and muscle problems, says Judy Simon, a registered dietitian nutritionist at UW Medicine who ...
Being underweight (BMI under 18.5) can reduce a woman's fertility by causing hormone imbalances that affect ovulation and the chance of getting pregnant. Compared to women in the healthy weight range, women who are underweight are more likely to take more than a year to get pregnant.
“Thinness is a heritable trait”
So thin people not only stay slim “by not having the obesity genes, but they also have different genes that protect them” from gaining weight, she said. The research concludes that “thinness, like obesity, is a heritable trait.”
Many women with low body weights still continue to get a regular menstrual cycle (3-5).