It’s a deceptively simple question, and one we ask ourselves all the time: how much should I weigh? It should be easy enough to figure out – you can look at a standard height/weight chart, estimate your frame size, and be presented with a good suggestion of your ideal weight. Or, you can use a Body Mass Index (BMI) calculator. Based on height and weight, it categorises you as underweight, normal, overweight or obese. However, it’s important to remember that these tools, while useful, don’t paint the entire picture.
Standard height/weight charts have been around for a long time. Ideal weight ranges for men and women are based on information gathered by the Metropolitan Life Insurance Company – something they’ve been doing since the 1950’s and last updated in 1999. After figuring out your frame size and height, you can see in which category you fall.
However, as height/weight charts and BMI calculators don’t take into account fat content or muscle mass, their insight into ideal weight is somewhat limited.
This matters for a couple of reasons. Take obesity, for example – this condition is diagnosed when a person has excess body fat, not just that they are overweight. As muscle weighs more than fat, a well-trained athlete or muscular individual may be categorised as ‘overweight’ by a height/weight chart or deemed as having a high BMI. In reality, they are not over-fat; their weight is higher simply because of their high muscle mass. Hence, for these people, standard height/weight charts do not apply.
On the flip side, there are people who have a large amount of body fat, but still look proportional. These people are often called ‘skinny fat’. Their BMI may fall in the ‘normal’ range on the height/weight chart, but technically, due to their high body fat percentage, they are obese.
As a result, figuring out your ideal weight is something that should be based on body composition analysis of how much fat and lean body mass you have. Since we know what the ‘good’ ranges of body fat are (about 14-18% for men; about 20-25% for women), knowing how much fat you have can help you more accurately determine where your weight ought to be. For example, if you’re a muscular guy with a high BMI but 15% body fat, your weight is probably fine. If you are a size 6 (UK) woman with 28% body fat, you would be wise to start doing strength training.
There are various methods that can determine body composition, but if they are not available to you, all you need is a mirror, your thumb and your forefinger. If you can ‘pinch an inch’ around your middle, above your knee, on the back of your arm, or on your back, you’re probably carrying too much fat. While you might not be able to work out precisely how much you should weigh, if you can ‘pinch an inch’, the easy answer for you is probably, ‘less than you weigh now’.
Written by Susan Bowerman, MS, RD, CSSD. Susan is a paid consultant for Herbalife.