Tracking bodyweight is one of the primary ways individuals use to measure success in both fat loss and muscle growth.
If you’ve ever carefully tracked your bodyweight from day-to-day, then you’ve no doubt noticed that rarely is your bodyweight the exact same from one day to the next.
But, why is that?
Ahead, we’ll discuss 6 reasons why your weight fluctuates from one day to the next as well as within the same day.
Why Your Weight Fluctuates
#1 Sodium Intake
This is far and away the most common reason behind weight fluctuations, especially for those who like to have a cheat meal or two during the week.
Sodium is an essential mineral and electrolyte that regulates extracellular fluid volume in the body. When you consume a meal high in sodium (your typical take-out, fast food, pizza, sub sandwich, etc), an imbalance in the fluid levels between your gut and vasculature is created, leaving you looking puffy and feeling bloated as the body figures out how to rebalance its fluids.
You’ll also notice that the next morning when you step on the scale your weight is higher, on account of water weight.
Fear not, though, this increase in weight is temporary, and your body will go back to its usual size once it eliminates the excess sodium and water.
One thing to keep in mind is that sodium is important for performance and overall health, so it’s important to consume enough sodium each day, especially if you maintain high levels of physical activity and/or train in hot environments. Individual sodium requirements will vary based on a variety of factors, including age, sex, bodyweight, height, physical activity, environment, etc., but suggested intake for the general (i.e. non-exercising) public is 2,300mg/day.
If you’re curious whether or not you’re consuming enough sodium each day (or perhaps, too much), simply log into the 1UP FItness App, which allows you to track your daily food & drink intake, including calories, carbohydrates, protein, fat, and sodium.
#2 Carbohydrate Intake
Many individuals are fearful of carbohydrates these days, but the reality is that carbohydrates are the body’s preferred source of energy during intense physical activity. They also can make your muscles look more filled out, help combat muscle breakdown, and support muscle growth.
At the same time, consuming too many carbohydrates can make you look puffy and soft as well as cause your weight to fluctuate. The reason for this is that for every gram of carbohydrate your body stores in the form of glycogen it also stores around 3 grams of water.
So, the more carbohydrates you eat, the more water that’s stored in your muscles, which can cause the number on the scale to go up. As we mentioned above, this increase in weight is temporary and will normalize as you burn up your glycogen stores.
#3 Weight of the Food & Drink You Consume
Your body weight includes a lot of things, such as how much muscle, fat, and bone mass you have. It also includes water stored in your body, the weight of your organs, and the weight of the food that’s in your stomach and GI system.
We all know that food and drink contain calories, which have an impact on our bodyweight, but the calorie content of a certain food or beverage is completely separate from its physical weight.
For instance, a cup of water weighs ~8 ounces (0.5 pounds) yet it contains zero calories.
So, if you eat some literally “heavy” foods, foods high in water and physical matter it could increase your body weight, even though it’s low in calories. The good news is that this weight increase isn’t from fat gain, it’s simply the weight of the actual food and drink you consumed.
This is one of the main reasons why you’re heavier at the end of the day than at the beginning of the day -- your body is literally full of food. Along these same lines, if you have a very big meal at night before bed (intermittent fasting), it may not be fully digested when you step on the scale in the morning, leading to a higher body weight measurement.
#4 Bowel Movements
Building off of the previous point, just as food has a certain mass and weight to it (and can cause your bodyweight to go up when consumed), it can have the opposite effect when leaving your system.
If you’re “backed up,” you could be storing some extra weight that could be throwing off your actual body weight. This is why fiber is so important. Fiber provides bulk to stool and helps keep you regular. It’s not a sexy topic, but it is an important one.
Furthermore, research indicates that most people don’t consume enough fiber each day from whole foods (fruit, veggies, whole grains, nuts, seeds, legumes). This is when a fiber supplement, such as 1UP Fiber Plus or 1UP Organic Vegan Greens & Reds Superfoods, comes in handy.
A good goal to aim for is 25-30 grams of fiber per day, or if you have very high calorie intakes (for instance you’re a super active athlete) shoot for 14 grams of fiber per 1000 calories consumed.
Hormones get blamed for a lot of things, some of which is warranted and some is not, but when it comes to weight fluctuations, hormones most certainly can have an impact.
For instance, when the stress hormone (cortisol) is elevated for prolonged periods of stress, it can wreak havoc on your physiology causing water retention, inflammation, and increased feelings of hunger -- all of which can contribute to increased body weight.
Something else to keep in mind is that females tend to be more affected by hormone-related weight fluctuations due to the menstrual cycle.
While you may not be able to do much about the monthly hormone fluctuations, you can take steps to reduce stress and inflammation by eating a well-rounded diet, exercising regularly, practicing mindfulness, and taking time to “unplug” from technology each day.
For added stress and hormone support, also be sure to check our Hormone Support Plus which provides stress & mood support, hormone balance, and menstrual regulation support.
Sweat is another big factor that can cause weight fluctuations.
Exercising with great intensity and/or in hot environments can lead to considerable water and electrolyte loss, which can result in decreased body weight.
FYI, excessive water loss due to sweating can result in dehydration, and even moderate dehydration (as low as 2% of bodyweight) can lead to increased feeling of fatigue, impaired performance, reduced cognitive function, and increased cramping.
As such, if you’re going to be engaged in rigorous activity for quite some time and/or exercising in a hot environment, it’s imperative to replenish fluids and electrolytes so you can maintain a high level of performance and reduce the risk of cramping/injury.
Our top-rated recovery supplement, Pure Rebuild, contains a comprehensive electrolyte blend as well as hydration-promoting ingredients in creatine, betaine, and glutamine to help you perform and recover optimally.