Ideal Body Weight – Devine Equation and Hamwii Method

In clinical nutrition in order to calculate energy and protein needs for a patient, ideal body weight is typically calculated.  One equation used is the Devine Equation.

For females this equation is:  45.5 kg + 2.3 (__ inches over 60 inches)

For example, a female who is 5’7″ should weigh 45.5 + 2.3 (7) = 61.6 kg

To get to pounds, simply take the kg and multiply by 2.2.

So, 61.6 kg x 2.2 = 135.52 lbs

For males this equation is: 50 kg + 2.3 (__ inches over 60 inches)

For example, a male who is 6’1″ should weigh 50 + 2.3 (13) = 79.9 kg

79.9 kg x 2.2 = 175.78 lbs

There is another formula used to calculate ideal body weight, the Hamwii method. This method is easier to use if you are more familiar with pounds and inches rather than kgs. It also allows for some “wiggle room” by taking into account body frame.

Females:  Add 100 lbs for the first 5 feet of height, and then an extra 5 pounds for each inch over 5 feet. Add 10% for “large” frames or subtract 10% for “small” frames.

For example, a female who is 5’4″ would have an ideal body weight of 100 + 4(5) = 120 lbs. Depending on her body frame, her ideal body weight could be between 108 lbs and 132 lbs (10% of 120 = 12 lbs).

Males: Add 106 lbs for the first 5 feet of height, and then an extra 6 pounds for each inch over 5 feet.

For example, a male who is 5’10” would have an ideal body weight of 106 + 10(6) = 166 lbs. Depending on his body frame, his ideal body weight could be between 149.4 lbs and 182.6 lbs (10% of 166 lbs = 16.6 lbs)

If a person is over 120% of their ideal body weight, then hospitals typically use an “adjusted body weight” which is then used as their “feeding weight” and used to calculate their energy and protein needs.

For example, a patient whose current body weight (CBW) is 189 lbs,  whose ideal body weight is 140 lbs is at 135% ideal body weight (IBW) .Their protein and energy needs will be based off of their adjusted body weight (ABW) which is found by:

ABW = .25(CBW – IBW) + IBW

So the patient in the previous example has an ABW of .25(189 – 140) + 140 = 152.25, or 152 lbs. If the patient’s energy needs are 25 kcal/kg, then you’d use 69.2 kg (152 lbs)  instead of 85.9 kg (189 lbs). This would make the patient’s energy needs 1730 calories rather than 2150.

Advertisements
Categories: Clinical Nutrition | Tags: , , , , , , , , , , , | 2 Comments

Post navigation

2 thoughts on “Ideal Body Weight – Devine Equation and Hamwii Method

  1. Joel Rush

    Adjusted body weight is a concept that is dying off with the advent of a more evidence based nutrition practice. It was removed from the American Dietetic Association Nutrition Care Manual with the last paper edition before the advent of the electronic Nutrition Care Manual. The science never really supported this practice but it gained usage before as a profession we focused on that style of care.

    Joel Rush MS RD CSO LD CNSC

Leave a Reply...What Do You Think?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Blog at WordPress.com.

%d bloggers like this: