If you regularly weigh yourself then you will have noticed that your weight can change significantly from week to week or even from morning to evening. You might be asking yourself ‘why does my weight fluctuate?’ We all know that our weight can change, yet women often report feeling more positive and more successful when the scales go down, and the opposite if the number goes up. They feel a moral connection to their value as people, and their scale weight. Regardless of them not doing anything differently; they haven’t changed as a person from AM to PM, no diet or activity change – yet their feelings of success or failure still relies on the number on the scales.
So, if our weight fluctuates day by day what does this mean? Is it really our fault when it increases over the day? Is it all because you had that biscuit with your cuppa and now you’ve ‘wrecked the diet’, or could there be something else going on?
What does the scale weight tell us?
When you step on the scales, what is the number telling you? The number on the scales is your total body weight.
Your body weight is made up of:
- Fat mass
- Muscle mass
- Bone Mass
- Water
The scale number does not tell you what percentage of each of these masses make up the total number. This is your body composition – some scales can tell you this, although they are often not very accurate.
People often see that the number has increased by 1 or 2 pounds and conclude that this must mean they’ve gained extra fat mass. However, these day-to-day fluctuations are unlikely to be related to fat mass.
Despite this, the idea that ‘I’ve put weight on’ is usually perceived as ‘I’ve got fatter’ and is often regarded in a negative way.
Now, there are separate issues in terms of your relationship with your body and food as to why the scales may trigger these thoughts. This may also be a good time to question whether weighing yourself is a healthy and helpful behaviour for you if it is causing you anxiety around food or your body. For now, let’s just break this down a little more as to the reasons why your weight may fluctuate, so we can understand why this is often just a totally natural part of your day, and is not because you didn’t try hard enough with your diet.
Why does my weight fluctuate each day?
You ate food or had a drink – Our daily weight is most likely to fluctuate based on our hydration status and the contents of our digestive system. How often you urinate and have bowel movements can also make a difference to how much you weigh.
You ate a salty meal – If you had a meal that was salty, then this may mean that you temporarily weigh more. Your body holds on to extra water due to the salt consumption. So as your body rebalances try to make sure you don’t become dehydrated.
Alcohol – If you drank alcohol last night, this may mean you are dehydrated and holding onto excess water.
You’re bloated – Bloating can make you feel like you have gained weight, even if you haven’t. Bloating might temporarily change your body shape, or increase your scale weight due to excess fluid, undigested food or trapped gas etc. Bloating is not linked to increased fat mass and is a temporary state. Most of the time bloating is totally normal, but of course if you experience excessive bloating then you can investigate this with your health care professional.
Hormonal changes – Hormonal changes linked the menstrual cycle can cause changes to scale weight. This again is likely to be a result of retained water as certain hormone changes may cause the kidneys to retain water and salts which can lead to bloating.
Medications – Some medications can cause water retention and would again lead to a change in scale weight.
Why is this important?
This study showed decreased motivation with weight gain in women. The study correlates with the experiences of many of the women I have worked with. On days where they have gained weight, they feel more negative in their mood, more guilt and shame and lower in confidence. The results showed that even a small amount of weight gain was distressing. These feelings led to lower motivation to maintain healthy behaviours such as physical activity and healthy eating. So what could have been a temporary natural fluctuation in body weight, could lead women in the longer term to less healthy lifestyles and lower levels of happiness. This highlights why focussing too much on the scales can take you further away from your goals.
What won’t help?
Overly restricting on calories. These small shifts in weight fluctuations are not linked to changes in fat mass. Therefore, restricting food is not going to be the cure but instead could lead to overeating later in the day. This could cause increases in fat mass over time as you are less in control of your food choices.
Summary
Your weight has been fluctuating each day for your entire life, but you were unaware until you monitored it. Every person’s body weight fluctuates around 2-5lbs a day, it’s totally normal.
Weight gain that is a trend over time is more indicative of increases in fat mass, although even then there may be other factors involved such as increased muscle mass if you have changed your body composition through exercise.
For some people weighing themselves is a benign behaviour that gives them data and keeps them feeling accountable to their weight loss goals. For others it can demotivate and make them feel guilt, shame and fear. This leads to engaging in less health-related behaviours. If you are one of these people, then consider if weighing yourself is a good idea at all – you don’t have to weigh yourself to measure success in your health and nutrition journey!
Weighing yourself multiple times a day is not a healthy behaviour and would indicate an issue with your relationship with food or body image. Even weekly weighing can be problematic for the reasons discussed above. I don’t tend to recommend weighing in my clinic as my clients are working on their relationship with food and body image, and these two actions usually don’t go together. But if you are wanting to keep an eye on the scales and don’t find it triggering, then hopefully this can help you to understand more about what is completely natural and normal.
Remember that daily weighing is not giving you an accurate reading, and by not obsessing over every pound you can take the pressure off by using the scales as a tool that offers one piece of a bigger picture. They’re not a ‘weigh to measure your success and value as a person.’
You are not defined by a number on the scale, and it is absolutely ok for your weight to fluctuate slightly.
N.B. Weight fluctuating by a few pounds is completely normal- If your weight has larger fluctuations in a day then this could indicate a medical concern, so you would be advised to speak to a medical professional. This blog is only offering general information, not specialist or individual advice.
