5 reasons why your weight can change every day

Tracking your weight long-term can help you determine if you’re on track to achieve your weight management goals. However, it is normal for the number on the scale to fluctuate from about 0.57 to 3.2 pounds from one day to the next. Here are some factors that may explain why.

When you choose to weigh yourself matters. Your body weight naturally fluctuates throughout the day due to changes in food intake, hydration, bowel movements and even sweat loss.

You can explain some of these changes by weighing yourself at the same time every day. For example, get into the habit of stepping on the scale in the morning after going to the bathroom and before eating breakfast.

What you ate over the course of a day can significantly influence short-term weight fluctuations. Foods high in carbohydrates or sodium can cause your body to retain water, which could lead to a temporary increase in weight.

Daily weight fluctuations caused by what you ate usually add temporary mass to your body until they are digested and excreted and do not usually reflect changes in body fat.

Hydration levels play an important role in short-term weight changes, since water makes up between 45 and 75% of our body mass.

Some people may have less fluid in their body if they are dehydrated or sweat excessively, so their weight may be slightly lower. On the other hand, consuming more sodium or exercising infrequently can lead to water retention and a temporary increase in weight, especially if you drink more water.

In these cases, weight changes because of the amount of water in your body, not because body fat has changed.

Hormonal changes can influence daily weight fluctuations by affecting water retention, appetite and even metabolism.

For example, during the menstrual cycle, fluctuations in estrogen and progesterone can lead to short-term fluid and sodium retention, temporarily increasing body weight.

Additionally, stress-related hormones, such as cortisol, can have an effect on eating habits. Cortisol also plays a role in the amount of water the body retains. This could contribute to changes in body fat that could affect your daily weight.

Stools can cause fluctuations in body weight, depending on the amount of waste you excrete daily. About 1.2 bowel movements in a 24-hour period is considered normal.

Constipation, or infrequent bowel movements, can cause temporary weight gain due to stool and water retention. Softer, runnier stools could lead to temporary weight loss.

What you eat can play a role in the composition of your stool, which can also lead to weight fluctuations. For example, a low-fiber diet can make stools smaller and stools less bulky – this has been linked to small weight reductions.

Overall, small daily fluctuations in weight are considered a normal part of life and rarely reflect actual changes in body fat. Water and food intake, hormones and other factors can influence your weight.

This means you don’t have to worry about small rises and falls you might see on the scale. However, if you notice a rapid, unexplained change in weight (whether it’s an increase or decrease), it’s important to see your doctor to rule out an underlying medical problem.