How often should we weigh ourselves, even if we are not fitness enthusiasts?

When it comes to health, there is hardly a more talked about topic than weight. Some experts advocate weighing ourselves every day to promote accountability for weight management, especially when we are following a diet and exercise program to lose weight. Others suggest avoiding the habit of watching our weight altogether, arguing that they can promote negative psychological reactions and unhealthy behaviors, especially when we don't like the number we see on the weighing machine.

1. Weekly weighing helps you control your weight

According to Professor Nick Fuller of Sydney University, research says that regular weight checking is an effective strategy for weight loss and management, mainly because it helps increase awareness of our current weight and any changes. A systematic review of 12 studies found that participants who weighed themselves weekly or daily for several months lost 1-3 BMI (body mass index) units more and regained less weight than participants who did not measure their weight frequently. The benefit of weight loss was clear with weekly weighing; daily weighing did not provide any additional benefit. 

Measuring your weight is important for weight management as you age. Adults tend to gain weight progressively by midlife. While average weight gain is typically between 0.5-1 kg per year, this modest accumulation of weight can lead to obesity over time. Weighing yourself weekly and tracking the results helps avoid unnecessary weight gain.

Keeping track of our weight can also help identify medical problems early. Dramatic changes in weight can be an early sign of certain conditions, including problems with our thyroid, digestion, and diabetes.

2. There are normal fluctuations in weekly weight

Our body weight can fluctuate both within a single day and across days of the week. Studies show that body weight fluctuates by 0.35% within the week and is typically higher after the weekend. There are many reasons for daily and day-to-day body weight fluctuations, many of which are linked to the amount of water in our bodies. The more common causes include:

A. The type of food we have eaten

When we eat more carbohydrates at dinner, we will weigh more the next day. This change is the result of our body temporarily retaining more water. We retain 3-4 grams of water per gram of carbohydrate consumed to store the energy we get from carbs.

When we eat foods high in salt, the amount of water in our body also increases. Our body tries to maintain a balance of sodium and water. When the concentration of salt in our bloodstream increases, a mechanism kicks in to restore the balance by retaining water to dilute the excess salt.

B. Our food intake

Whether it is 30 grams of nuts or 65 grams of lean meat, everything we eat and drink has a weight, which temporarily increases our body weight while we digest and metabolize what we have eaten. We weigh less first thing in the morning after our food intake is restricted overnight and more in the evening after our daily food and drink intake.

C. Exercise

If we weigh ourselves at the gym after a workout, there is a good chance that we will lose weight due to fluid loss through sweating. The amount of water lost depends on things like the intensity and duration of our workout, the temperature and humidity, as well as our sweat rate and hydration level. On average, we lose 1 liter of sweat during an hour of moderate-intensity exercise.

D. Hormonal changes

Hormone fluctuations during your menstrual cycle can also affect fluid balance. Women may experience fluid retention at this time and temporarily gain 0.5-2 kg of weight. In particular, the luteal phase, which represents the second half of a woman's cycle, results in fluid moving from your blood plasma into your cells and causing swelling.

E. Bowel movements

Going to the bathroom can cause a small but immediate weight loss as waste material is removed from the body. Although the amount lost will vary, we generally lose about 100 grams of weight through our daily bowel movements.

All these fluctuations are normal, and they do not indicate significant changes in our body fat or muscle mass. However, observing these fluctuations can lead to unnecessary stress and fixation with our weight.

3. Avoid stress and panic

Weekly weighing helps to avoid the stress of daily weighing and the panic of losing weight. Frequent weighing can lead to an obsession with weight gain and do more harm than good. Often, when we see that the needle on our scale is not moving in the direction we want or expect, our reaction is to restrict our food intake further or start a fad diet. Besides not being fun or sustainable, these diets also ultimately increase our weight rather than reverse it.