SINGAPORE – How often should you weigh yourself? It depends on your physical and mental health, say experts.

Tracking your weight can help track the general state of your health. Weight gain might lead to obesity, or the accumulation of excess fat in the body, which increases the risk of health issues such as high blood pressure or diabetes. Unusual weight loss, on the other hand, can signal that something is wrong.

However, some people may find weighing themselves stressful. Weight can also be a trigger for those with eating disorders.

Associate Professor James Yip, director and senior consultant at the National University Heart Centre, Singapore, says: “For individuals without disease, weekly to monthly monitoring of one’s weight is good enough.”

He adds that further investigation may be needed if there is “clinically important weight loss of 5 per cent of the usual body weight over six to 12 months”, when there is no other apparent cause for such weight loss.

Body weight can fluctuate by 1 to 2kg during a single day, depending on the amount of fluid in your body, so doctors recommend weighing yourself at the same time of day and under the same conditions, such as before breakfast.

People with conditions such as heart and kidney failure are encouraged to weigh themselves daily to monitor the amount of fluid in their bodies, says Prof Yip, who is also head of the academic informatics office at the National University Health System.

“Weight is a vital parameter that helps us understand how much fluid content such patients hold,” he adds. Daily weighing can help these patients prevent dehydration and fluid overload, which may manifest as swelling of body parts and breathlessness.

Tracking your weight regularly can also help you maintain your weight or manage obesity. Dr Lee Phong Ching, director of Singapore General Hospital’s Obesity Centre and senior consultant at its department of endocrinology, says: “As a result of regular self-monitoring, small changes in body weight can be identified early, and changes in diet and exercise behaviour initiated as a result.”

Dr Lee suggests weekly monitoring of weight in obesity management, citing research conducted by the United States National Weight Control Registry. This research showed that most people who were able to lose more than 13.6kg, and maintain this weight loss for more than one year, weighed themselves at least once a week.

Weighing yourself four times a week appears to be more effective, according to research led by Dr Lim Su Lin, head and chief dietitian at the National University Hospital’s department of dietetics.

The paper published in 2022 in the medical journal JMIR Diabetes studied 171 adults with Type 2 diabetes or prediabetes. Those who tracked their weight about four times a week or more had 6.8 per cent weight loss after six months, compared with 1.5 per cent weight loss for those who tracked their weight about once a week.

So, should you step on the scale every day?

It is possible to become obsessive about weighing oneself, cautions Dr Lim.

“There is always the risk that people who have disordered eating habits or who are already too underweight may want to lose more weight,” she says.

Dr Lee from SGH says: “For some individuals, weighing oneself can be a stressful endeavour. A weekly or monthly approach may be better if you find that weighing yourself too frequently is affecting your mental health.”

Fitness trainer Petrina Ann recommends a weekly weigh-in for clients to observe patterns and progress. Weight is tracked at the same time, usually in the mornings.

“Anything done more than once a week may then actually set back progress,” says the trainer with Alpha Beast Fitness. “For example, daily weigh-ins may highly fluctuate due to water retention. For some people who are fixated on numbers on the scale, this may come as a source of demotivation.”

She adds: “Part of weighing yourself the right way is recognising that numbers on the scale do not always tell the whole story. Instead, observe your energy levels, the way you feel and the way your clothes fit. For people who are triggered by numbers or who have eating disorders, progress can sometimes mean realising that the scale is not for you.”