I come from a family of people who struggle with their weight. In fact, three out of four of my grandparents developed type II diabetes. So I know I need to be careful when I gain weight, as genetically I am holding a loaded gun (“Genetics may load the gun, but lifestyle pulls the trigger”). What’s more, Coeliacs who are diagnosed late in life often put on weight rapidly after years of essentially starving.
However, I am not a scale obsessive. I learned early on that it is not body weight that matters so much as measurements and body fat. It is absolutely possible to gain muscle mass, and therefore weight, but lose body fat. You may weigh more but fit into a smaller size! For over 13 years I have measured myself on the first day of every month, using a tailor’s tape measure. I stick to the basics of bust, waist and hips, plus mid-thigh, as I carry my weight on my legs.
Eight years ago I bought my first bioelectric impedance scale – it measures body fat and muscle mass as well as weight using a small electric current. According to the American Council on Exercise, anything below 30% is considered normal for a woman, and anything below 20% is normal for a man. Most athletes have body fat percentages below 15% for men and 25% for women, depending on the sport – obviously endurance sports require a leaner physique than something like hammer throwing! Having said that, these scales are far from perfect (see The Problem with Body Composition Scales) so you have to take these percentages with a pinch of salt.
If a scale is all you have, you want to weigh yourself once a week, always on the same day. The best time is first thing in morning after you have been to the bathroom, but before you have dressed or had anything to eat. As you breathe out water vapour as you sleep, you will always wake up dehydrated. Then as you eat and drink throughout the day, you re-hydrate. This is why you weigh more at the end of the day than at the start. Your end of day weight is also affected by what you had to eat that day, how much exercise you did, and your bowel movements. Obviously, what you eat and how much you exercise can vary a lot from day to day, which is why weighing yourself once a week works best for consistency. Note also that most women weigh more the week before their period than at other times in their cycle.
If you are trying to lose fat and gain muscle, you need to measure the right things at the right time!