SARAH DI LORENZO: How your BMI can tell you little white lies when you’re measuring your health goals.

It is so important not to ever compare your weight to someone else, even an identical twin. There are so many factors that can influence our weight such as sleep, exercise, height, diet, hydration, health status, relationship with food, muscle mass, body fat and body water. There are some general guidelines for a healthy person which is what we see with BMI or body mass index but even this is flawed.

I tell my patients a healthy weight is one where you feel happy, are in proportion to height and eating where you are not gaining weight, rather maintaining your weight and not driving any chronic disease.

BMI or Body Mass Index is a calculation that relates to a person’s weight to their height. It is an easy general guide that is noninvasive, quick, inexpensive and designed to estimate a person’s amount of fat by comparing it to their height. The general rule is the higher the BMI indicates more body fat which is associated with health risks like type 2 diabetes, heart disease and stroke while a low BMI indicates possible malnutrition and other health problems.

The thing about BMI is that it is not really accurate. For example it can’t distinguish bone, fat and muscle. More muscular people can actually have a high BMI. BMI also does not indicate fat distribution and can’t measure this. BMI also can’t reflect changes in the body composition such as ageing, ethnicity, people with physical disabilities, children, teenagers and pregnancy.

BMI is just one of many diagnostic tools a healthcare provider can use in conjunction with blood pressure, cholesterol, waist circumference and DEXA scans that look at body fat measuring. In essence it is useful only really as a starting point but not a definitive measurement.

So when it comes to how much you should weigh is so much more than just what you see on the scale, this is very hard for so many people to understand. As a practitioner I look at body fat rather than the weight on the scale. A healthy weight is what is right for your body composition, health status and height and this is where BMI can be a helpful tool but as mentioned it has limitations.

There are many other considerations when working out your healthy weight efficiently. For starters look at your body composition with a measurement of body fat percentage, waist circumference and muscle mass. Looking at blood pressure, blood sugar levels, blood pressure and how often someone is exercising are also good indicators. Other considerations for a healthy weight include how much energy you have, mobility, stress and general wellness are good indicators as well.

So the definition of a healthy weight in simple terms is where you are eating a balanced healthy diet, not gaining weight and don’t have non communicable diseases such as type 2 diabetes, fatty liver and insulin resistance.

Key strategies to maintain a healthy weight include eating a healthy diet with all food groups, exercising regularly, reduced intake of processed foods, portioned controlled meals and portioned controlled meals.

To get more specific advice seek a check up by a registered healthcare professional to look at your health comprehensively using tools that can include BMI. Using a BMI is a good starting point to understand what your healthy weight should be but just one of many assessments you need to do to truly determine what is the healthiest weight for you for long term optimum health and wellness.