Weight FAQs

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1. Why is your weight measurement important?

Your current weight is needed to calculate your BMI and body fat percentage at the HealthZone. It is also important to help us provide you with the most relevant exercise and meal plan when doing the Energy Quiz.

2. What is Body Mass Index (BMI)?

BMI expresses your weight relative to your height. This is how you calculate it:

BMI = weight (kg) / height squared (metres2)
= kg/m2

BMI is automatically calculated on the HealthZone using your entered height and most recent weight measurement.

The norms that we use for BMI are adapted from those standards set by both The World Health Organisation (WHO) and The American College of Sports Medicine (ACSM).

BMI Where do you fit in?
< 18.5 You might need to put on a bit of weight
18.5 - 24.9 Looking good
25 - 29.9You might need to lose a little bit of weight (body fat) - consider your waist circumference and body fat % for a better understanding
≥ 30 Unless your body fat % is within an acceptable range, we suggest you make the necessary exercise and dietary changes to reduce your body fat and improve your health status.

Note that there are limitations in interpreting your BMI result: remember that BMI looks at your total weight and does not consider your body fat percentage or lean muscle mass. A person may have a high BMI, because of lots of muscle and not because he/she is overweight/obese (very fat). When calculating your ideal weight, it is important to consider your body fat percentage, your muscle mass and your bone size (your frame).

3. How often should I weigh myself?

Your weight fluctuates throughout the day depending on your activity level and how much food and drink you've had. Your day-to-day weight will also vary depending on how your body retains fluids. You don't need to weigh yourself more than once a week.

4. What makes my weight reading vary?

As with blood pressure and body fat, there're many things that can influence your weight measurements. Time of day, what you're wearing and what you've eaten and drunk that day are all important, as well as the accuracy of the scale used to measure your weight.

Handy tips before you step on the scale:

  • Go regular – always weigh yourself at the same time of the day.
  • Go the same – try to always weigh yourself using the same scale and wearing similar weight clothes as you wore the last time. Also, always go with or without shoes.

Large fluctuations in weight on a day-to-day basis is usually related to your body's hydration status, and not to picking up or losing body fat or muscle.