newsprompt.coIDEAL BODY WEIGHT
All the formulas are for adults age 18 or older. For children and teens, please refer to the following weight charts published by the Centers for Disease Control and Prevention (CDC).
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CDC weight chart for boys between age 2 and 20
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CDC weight chart for girls between age 2 and 20
AGE
In theory, age shouldn’t be a determinant of an IBW figure from middle age onwards because the height of a human generally stays constant and does not go through the growth in height apparent in young ages. It is actually expected for human males and females to lose 1.5 and 2 inches in height respectively by age 70. Therefore, the only variables acting on body weight are muscle mass and body fat, and the many different factors associated with the two, such as illness, diet, and exercise. However, it is important to remember that as people age, lean muscle mass decreases and accumulation of excess body fat is easier. This is a natural process of human biology over a lifespan, though actions can be taken to thwart it such as controlling for important variables such as diet, exercise, stress, and sleep.
GENDER
Generally, females weigh less than males even though they are prone to carry more body fat.. The physical, genetic makeup of a male body naturally has more muscle mass, which is heavier than fat. Not only that, but women are less dense (physically); they have lower bone density. Last but not least, males tend to be taller than females.
HEIGHT
Height becomes the main factor in an IBW figure. Obviously, the taller the person, the more muscle mass and body fat required to fill it out, resulting in more weight. A male at a similar height to a female should weigh about 10-20% heavier.
FORMULAS
G. J. Hamwi Formula (1964)
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Male: |
48.0 kg + 2.7 kg per inch over 5 feet |
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Female: |
45.5 kg + 2.2 kg per inch over 5 feet |
Invented for medicinal dosage purposes.
B. J. Devine Formula (1974)
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Male: |
50.0 + 2.3 kg per inch over 5 feet |
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Female: |
45.5 + 2.3 kg per inch over 5 feet |
Similar to the Hamwi Formula, it was originally intended as a basis for medicinal dosages based on weight and height. Over time, the formula became a universal determinant of IBW.
J. D. Robinson Formula (1983)
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Male: |
52 kg + 1.9 kg per inch over 5 feet |
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Female: |
49 kg + 1.7 kg per inch over 5 feet |
Modification of the Devine Formula.
D. R. Miller Formula (1983)
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Male: |
56.2 kg + 1.41 kg per inch over 5 feet |
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Female: |
53.1 kg + 1.36 kg per inch over 5 feet |
Modification of the Devine Formula. Results are skewed higher than other formulas.
HEALTHY BMI RANGE
The World Health Organization’s (WHO) recommended healthy BMI range is 18.5 – 25 for both male and female.
BMI is a commonly used metric in determining IBW. It is widely used in the medical field as a quick indicator of possible health complications. Generally, the higher the BMI, the higher the chance a person has to suffer health problems from obesity and diabetes, to heart disease and many more. It is a indicator used by doctors to advice their patients of potential health problems, especially if there is a noticeable progressive increase in their BMI, and is currently the official metric for classifying individuals according to different obesity levels.
WHAT IS THE PROBLEM WITH BMI?
BMI is a very simple measurement which does not take into account the person’s waist, chest or hip measurements. As an extreme example of this, an Olympic 100m sprint champion is likely to have a BMI higher than a couch potato of the same height. The couch potato may have a big belly, not much muscle and a lot of body fat on his hips, upper thighs, in his blood and on other parts of his body. While the athlete will have a smaller waist, much less body fat, and most likely enjoy better health. Using a pure BMI criteria, the couch potato may be considered healthier.
BMI does not take into account bone density (bone mass). A person with severe osteoporosis (very low bone density) may have a lower BMI than somebody else of the same height who is healthy, but the person with osteoporosis will have a larger waist, more body fat and weak bones.
Many experts criticize BMI as not generally useful in evaluation of health. It is at best a rough ballpark basic standard that may indicate population variations, but should not be used for individuals in health care.
Put simply: experts say that BMI underestimates the amount of body fat in overweight/obese people and overestimates it in lean or muscular people.
WHY FRAME SIZE IS IMPORTANT
Other ideal body weight calculators don’t factor for frame size and this is an important factor in determining an ideal body weight for a person of your height.
The term frame size refers to the mass of your skeletal structure. Those with more bone mass will weigh more than people with less bone mass who are of similar height. However, this isn’t factoring for bone density.
