Harvard Health Letter

Measuring how fat we are

Weighing the pros and cons of three measures of adiposity.

Most of us have our private ways of assessing how fat we are. We feel the pants getting snug — or loose, if we're lucky. We take a glance in the mirror or at our reflection in the shopfront window.

Of course, there are more objective ways of answering the question. Plain old weight is a good clue, but it's a total that includes bones, muscles, organs, hair — not just fat. The tried-and-true way of measuring just fat involves getting weighed while fully submerged in water. The difference between your weight in water and your regular weight is used to calculate body density, and from that, the proportion of the body that's fat. But few of us are going to subject ourselves to regular dunking.

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