What is BMI?
Body Mass Index, or BMI, is a term you will often hear when starting a weight loss journey. It is an internationally recognised tool that is commonly used to determine how your weight is classified according to your height.
How to Calculate BMI
To calculate your BMI, you divide your weight by your height in metres squared. The equation looks like this:
BMI = Weight (kg)
Height (m) x height (m)
What does your BMI mean?
The answer to this equation will fall within a range of different classifications:
- BMI less than 18.5 – Underweight. This is considered to be less than your healthiest weight for your height, and it may be associated with health problems for some people.
- BMI in the range of 18.5-25 – Normal weight. This is regarded as the healthiest weight, and the weight range connected to the lowest risk of illness for most people.
- BMI above 25 – Overweight. This is considered to be above your healthiest weight for your height and it may be associated with health problems for some people.
- BMI above 30 – Obese. This is significantly above the healthiest weight for your height, and is associated with increased risk for health problems such as heart disease, high blood pressure and diabetes.
Is Body Mass Index the right guide for everyone?
While these BMI ranges can certainly provide guidance on what a healthy weight for your height might look like, aiming for a healthy BMI is not the only way to achieve improvements in your health. BMI is a practical measure, however there are limitations to using this alone as a measure of whether or not you are healthy. Here are some factors to consider when looking at your BMI:
- It does not distinguish between fat mass, muscle mass or fluid in your body.
- Muscle weighs more than fat and so a very muscular person may have a higher BMI.
- If you have a health condition that causes you to retain fluid, this may falsely increase your BMI.
Your frame size can be another factor to consider when determining a healthy weight. Frame size can be classified as small, medium or large and somebody of a small frame size will more than likely have a comfortable weight that is lower than that of someone with a large frame size of the same height.
Motivators in Your Weight Loss Journey
Waist circumference is a measure often used in addition to BMI and can be a useful tool for self-monitoring. Your waist measurement can help to identify if you are carrying excess internal body fat around your middle. It may also be a better predictor of certain chronic conditions than BMI, such as cardiovascular disease and type 2 diabetes. If achieving a BMI within the healthy weight range is not a motivator you connect with, reducing your waist circumference might be. A waist circumference above 80cm for women and above 94cm for men is associated with an increased risk of chronic conditions. A waist circumference above 88cm for women and above 102cm for men is associated with a substantially increased risk of chronic conditions.
Percentage weight loss
Research shows us that losing 5-10% of your current weight can produce health benefits such as improvements in blood pressure, blood cholesterol and blood glucose levels. So if reducing your BMI or your waist circumference don’t feel like suitable motivators for you, losing 5-10% of your current weight might be. If you currently weigh 90kg, losing 5-10% of your current weight would mean losing somewhere between 4.5 and 9 kilograms. Research also shows that the more weight you lose, the greater the health benefits, particularly if you lose more than 5% of your body weight and maintain this for life.
Focus on what motivates you
At Jenny Craig, the results you choose to place your focus on are entirely up to you. Your Ccoach will take your weight weekly, while at home you have the option to do this daily if you choose to. Your measurements will be taken monthly. Your BMI can be recalculated as you lose weight as well. Remember that in addition to numerical results, there are broader changes to celebrate as well, and these are the gradual long-term changes that you will be making to your food and physical activity choices.
Our most recent weight loss program – Max Up helps you achieve your BMI and fitness goals with an all-rounded approach with the help of personal weight loss coaching, flavourful & dietitian approved meals and a holistic approach to weight loss.