For a 16-year-old female who is 5'4", being underweight generally means a Body Mass Index (BMI) below 18.5 for adults, but for teens, it's determined by percentile charts (below the 5th percentile for age/sex). A healthy weight range for an adult 5'4" female starts around 108-110 lbs (BMI 18.5) up to about 130-145 lbs, so a weight significantly below this, like under 107 lbs, would likely be considered underweight, but a doctor should use BMI-for-age percentiles for teens.
Women with a BMI of less than 18.5 are considered underweight. The average woman's height is 5 feet, 4 inches. If you weigh 107 pounds or less at this height, you are considered underweight with a BMI of 18.4. A healthy weight range for that woman would be 108 to 145 pounds.
Underweight: BMI is below the 5th percentile age, gender, and height. Healthy weight: BMI is equal to or greater than the 5th percentile and less than the 85th percentile for age, gender, and height. Overweight: BMI is at or above the 85th percentile but less than the 95th percentile for age, gender, and height.
Being underweight can lead to many different health problems. There are many causes of being underweight, including physical and mental health problems and not having good access to food.
A BMI < 16.0 is known to be associated with a markedly increased risk for ill health, poor physical performance, lethargy and even death; this cut-off point is therefore a valid extreme limit.
In general, your plan may include:
From a clinical perspective, an individual is considered “too skinny” if they are deemed underweight. According to the Centers for Disease Control, an individual is underweight if their Body Mass Index (BMI) is below 18.5 [1].
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.
The Complications of Being Too Thin
Registered dietitian Katherine Basbaum shares, “It's a jumping-off point to determine a healthy weight, but definitely not one-size-fits-all of healthy body factors." To get a rough idea, if your BMI is less than 18.5, you're considered underweight.
That means the ideal weight for a 5-foot-4 woman would be 108 to 145 pounds, according to the CDC. The ideal weight for a 6-foot man would be between 137 and 183 pounds.
under 18.5 – underweight. 18.5 to 24.9 – within the healthy range. 25 to 29.9 – overweight. 30 to 39.9 – obesity. 40 or above – severe obesity.
For example, a woman who is 5'4" with a small frame may weigh around 108 pounds and still be considered healthy, while a woman of the same height but with a large frame may weigh 142 pounds and also be within a healthy range.
Body Shapes with the Highest Risk of Health Problems
Apple and pear body shapes tend to have the highest risk. Apples tend to be at greater risk for heart disease, diabetes, and strokes because they hold a larger amount of tummy fat.
Not eating enough can have several symptoms, such as persistent hunger, low energy, impaired concentration, and frequent sickness. Chronic undereating can have serious health consequences. It's best to consult a healthcare professional or registered dietitian if you suspect you are undereating.
Do
What are the symptoms of a growth disorder?
70kg isn't inherently heavy for a woman; it depends heavily on height, body composition, and build, but it often falls into a healthy range for taller women, while for shorter women, it could lean towards overweight. For example, a 175cm (5'9") woman at 70kg has a healthy BMI, but a 163cm (5'4") woman at the same weight might be considered borderline overweight, according to this article from The Daily Telegraph.
Adolescence is a time when girls will gain more fat tissue and add fat stores on their thighs, breasts, and hips. In boys, the weight gain is mostly from muscle gain. Knowing that these body changes will happen can help reassure children that they are growing as they should.
The bottom line for skinny girls to gain weight fast is to focus on a balanced diet with more calories, proteins, and healthy fats, combined with a workout plan that emphasizes strength training. Also, gaining weight should be a gradual process.
While there are medical reasons this could be happening, it could also be that they are growing taller, exercising a lot, are too busy or distracted to eat appropriately-sized meals, or they may simply have a high metabolism (the way our body burns calories).