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Ever stepped on the scale and wondered why your weight seems to dance around day by day? 

You’re not alone. 

In this episode, we explore the multiple factors contributing to daily weight fluctuations. 

From food weight, carbohydrate intake, sodium levels, to stress, strength training, the menstrual cycle, and even alcohol consumption—each plays a unique role in your body’s weight changes. 

You’re going to learn the best practices for tracking your weight effectively and understand how to interpret these fluctuations for a more accurate picture of your fitness progress.


0:00 – Please leave a review of the show wherever you listen to podcasts and make sure to subscribe!

2:20 – Your weight is going to fluctuate.

5:54 – What is food weight?

7:29 – How do carbs affect weight fluctuation?

10:57 – Legion One-on-One Coaching:

13:45 – How does sodium affect body weight?

15:15 – How does stress affect your weight?

19:55 – Can strength training affect weight fluctuation?

23:07 – Menstrual cycle effects on weight

23:52 – How can alcohol affect your weight?

24:18 – What is the best way to track your weight accurately?


Mentioned on the Show:

Legion One-on-One Coaching:

What did you think of this episode? Have anything else to share? Let me know in the comments below!


Hey, hey, I’m Mike Matthews and this is Muscle for Life. Thank you for joining me today for a new episode on the topic of weight fluctuation, which is something that I have written and spoken about at least tangentially over the years, but I wanted to produce one episode on it because it is a common concern.

It is something that I get asked about fairly often. And specifically, the question is, Why does my weight fluctuate so much? And when people are trying to lose weight, then that’s where the concern comes in. Why did my weight jump up two pounds, three pounds, even five pounds overnight? Or why has my weight been trending?

Upward over the last 3, 4, 5 days when I’ve been following my meal plan. Or why has my weight been stagnant for the last X number of days even though I’ve been following my meal plan and so forth. And all of that can be confusing, it can be frustrating, it can be discouraging, it creates problems that people try to find solutions for and unfortunately many of those people are led astray in their quest for for the solution they’re led away from scientific non negotiable principles like energy balance and hoard pseudo scientific quackery And in fact, that’s how a lot of pseudoscientific quackery is marketed as a solution, a breakthrough solution, a cutting edge solution, an esoteric solution, maybe even a suppressed solution that they don’t want you to know about, to a thorny problem that many people are trying to solve.

And so anyway, in today’s episode, we are going to clear the fog away, and you’re gonna learn in clear and simple terms why your weight fluctuates, why it can fluctuate a lot, what you can do to better manage those fluctuations, even minimize those fluctuations, not that they’re harmful, but why they’re harmful.

They can be obnoxious when you are trying to lose weight, for example, or even gain weight or maintain weight and you are trying to keep tabs on your weight because it is an indicator of progress, whether it’s losing body fat, gaining muscle, or just maintaining body composition. Okay, so let’s start this discussion at bedrock, and that is that your weight is going to fluctuate always.

And that’s true whether you are in a calorie deficit consistently to lose fat, whether you are in a calorie surplus consistently to gain. muscle and strength or to maximize muscle and strength gain, or whether you are consistently eating more or less the amount of calories that you’re burning to maintain your body composition, your weight is going to fluctuate and it’s going to fluctuate in inconsistent and unpredictable ways.

Many people are not aware of this. They go into a fat loss phase or a lean bulking phase or a maintenance phase with the wrong expectation. They visualize, let’s, let’s take a fat loss phase. Many people, Assume that their progress is going to be more or less linear as long as they do what they need to do.

They know they don’t need to be perfect. They just need to be good enough and maintain a calorie deficit at least week to week and so forth. And when they start that process, this is this is people usually who are new and they haven’t learned the things that I’m teaching in this podcast, but they.

Visualize maybe a graph in their mind. If you can think of a graph, uh, and you have your body weight on the vertical access, and then you just have time on the horizontal access, and they just see a nice, clean, straight line just going down, down, down to their target weight. In reality, though. that isn’t how weight loss occurs.

In reality, you can lose a pound one week, you can lose nothing over the next two weeks, you can then suddenly lose three pounds of weight in the next week, and then you can gain a pound back, you can lose it a few days later, and so forth. And so in reality, when you graph a successful, that’s a successful weight loss phase, by the way, It looks more like a line that goes down and up and down and up even more, and then way down and then a little bit up and then flat and then up and then down and down and down and then up.

And over time though, the trend is downward. If you are doing the most important things, mostly right, most of the time, but you’ll never ever get a clean linear. And that is true of a weight gain or lean bulking muscle and strength gain phase as well. Some weeks you gain a little bit of weight. Some weeks you gain a little bit more weight.

Some weeks you gain no weight. Some weeks you even lose a little bit of weight. Now, what happens to many people who don’t understand what I’m going to teach you in today’s podcast is when their weight moves in an undesirable direction, that can be up if you’re trying to lose weight, that can be down if you’re trying to gain weight, or that can be up or down, depending on the person, if you’re trying to maintain weight, they get weight.

It’s a little bit worried, and then if their weight continues to move in an undesirable direction, they get more worried and they start to wonder if they’re doing something wrong or if something’s wrong with them, wrong with their hormones, wrong with some other aspect of their physiology, do they need to make changes to their diet, do they need to make changes to their training, and enough of that becomes very discouraging.

Now, what I want you to understand is that experience is totally normal. That is what you should expect. That is the rule, not the exception. And it’s influenced by various factors related to our diet, our lifestyle, and our biology. And that’s what I’m going to talk about in today’s episode. So let’s start with some factors related to diet.

Let’s talk about food weight, something that many people don’t consider. So we eat food. Our weight goes up, of course, right? Because the food’s mass doesn’t just disappear when we swallow it. It has to first pass through our digestive system. Now, if you consider that most of us are eating a few pounds of food every day, and that the process of eliminating that food can take anywhere from one to three days, you immediately see how your weight can fluctuate by a few pounds on a day to day basis, especially if you have a lot of variety in your diet.

If you’re not Eating more or less the same meals every day, the same foods every day because volume and calories are going to change from food to food. So you might go for a few days eating higher volume, lower calorie foods that add more weight like fruits and vegetables and a lot of the. Um, relatively nutritious, unprocessed foods that you should be eating, but then there might be a couple of days where you’re eating foods that are more calorically dense.

So there are more calories in less volume, which generally means less weight. There are exceptions, but that’s going to be generally true. So if for a few days you’re eating more, let’s say highly processed foods with added sugar, with added fat, a lot of calories in small Food packages, so to speak, well, then you are eating maybe even more calories, but the weight of the amount of food that you’re eating can be less.

And so that’s the first dietary factor you need to understand. And the next one is weight fluctuation from carbs. Now, when you eat carbs, your body converts them into glucose, blood sugar and glycogen, which is a form of carbohydrate that’s stored in your muscles and. liver. Now, your body also holds water with the glycogen.

In fact, research shows that it stores about three to four grams of water with every gram of glycogen. And that’s why eating a high carb meal or eating a lot of carbs in a day or over the course of several days can dramatically Increase your weight by multiple, multiple pounds, even upward of 10 pounds.

If we’re talking about a couple of days, especially if you are coming off of a period of lower carb intake, and then you carb up, you can gain a lot of weight very quickly. That is not body fat. We’re talking about glycogen and water. So for example, two slices of bread. You make a sandwich that contains enough carbs to store an extra about one third pound of water.

And that’s just a couple slices of bread. And so that’s how weight can swing dramatically upward when you eat carbs. And that also explains why weight can swing dramatically downward when you reduce your carbohydrate intake or when you use up. The glycogen stored for energy, which then also releases the water that that was stored with the glycogen.

And so when a person’s carbohydrate intake fluctuates a lot day to day or week to week, their weight is going to fluctuate a lot as well. And it could have nothing to do with body fat. They may be gaining or losing body fat, but they also could be more or less just maintaining the exact same amount of body fat.

But. They could be experiencing rather large swings upward and downward in their weight. For example, a common dietary pattern here in the West is to eat, let’s say fairly well, to eat mostly nutritious foods during the week and even restrict calories during the week because of the weekends when then there’s a lot of indulgence.

And so then, during the week, we have this lower carb, lower calorie diet, and then the weekends are higher carb, higher calorie, and that is a recipe for a lot of weight fluctuation. By the end of Sunday, weight is way up, and then by the end of Thursday, or Friday weight is way down and whether body fat is up or down, of course, depends on energy balance.

If we look at that week and we add up all of the calories eaten, and then we add up all of the calories burned, the difference between those two numbers will tell us what happens to body composition, to body fatness in particular. If all the calories eaten, are greater than all the calories burned, body fat will have been gained to some degree, especially if a lot of the excess calories came from dietary fat and doubly, especially if alcohol was involved.

Now, by the same token, if calories in and out for that week are more or less matched, then body fatness will be more or less the same, regardless of what. Happens or has happened with body weight, body weight might have fluctuated over the course of that week, it might have fluctuated by 5, 7, 7 up and then down and body fatness has stayed exactly the same.

the same. I’ve worked with tens of thousands of people over the years and the biggest thing I see with the people I have helped the most is they’re often missing just one crucial piece of the puzzle. And if you are having trouble reaching your fitness goals as quickly as you’d like, I’m going to guess it is the same thing with you.

You are probably doing a lot of things right, but dollars to donuts, there’s something you’re not doing right. And that is what is giving you most of the grief. Maybe it’s your calories. Maybe it’s your macros. Maybe it’s your exercise selection. Maybe it’s food choices. Maybe you are not progressively overloading your muscles.

And whatever it is, here’s what’s important. Once you identify that one thing, Once you figure it out, that’s when everything finally clicks. That’s when you start making serious progress. It’s kind of like typing in your password to log into your computer. You can have all the letters, numbers, and symbols right, except just one.

And what happens? You can’t log in, right? But, as soon as you get that last remaining character right, voila, you’re in business. And I bet the same can be said about the body you really want. You are probably just one major shift, one important insight, one powerful new behavior away from Easy Street. And that’s why I offer VIP one on one coaching where my team and I can help you do exactly that.

This is high level coaching where we look at everything you’re doing and we help you figure out that one thing that is missing for you. And it can be a couple of things too, that’s fine, there’s no extra charge for that. But once we figure it out, that’s when you start making real money. Progress. That’s when you start looking better and feeling better.

So if you’re ready to make more progress in the next three months than maybe you did in the last three years, and yes, that has happened for many of our clients, head on over to muscleforlife. show slash VIP. That’s muscle F O R life. dot show slash VIP and schedule your free consultation call, which by the way, is not a high pressure sales call.

It’s just a friendly chat where we get to learn about you and your goals and your lifestyle and then determine whether our program is right for you. Because sometimes we do speak with people who just aren’t a good fit for our service, but we almost always have other experts and other resources to refer those people to.

So, if you are still listening to me, and you are even slightly interested, go schedule your free consultation call now at muscleforlife. show slash VIP. Okay, so the next dietary factor to consider is sodium. Because sodium brings water into cells and that’s why eating salty foods can increase body weight.

But what you may not know is that it can significantly increase body weight. If you had a very salty meal, a larger meal, especially one with a lot of carbs. You could gain several pounds of water weight within hours. So you eat a lot of sodium at lunch and maybe it didn’t even feel like that much food, but it was a lot of sodium.

And then you are three pounds heavier, two pounds heavier, just a few hours later. And your body will adjust. It will correct this, but it can take a bit of time. If you eat a lot of high sodium food. So if you have a high sodium day. For example, it can lead to a pretty dramatic increase in water retention and therefore body weight for a couple of days.

It can take your body a couple of days to to normalize. That means that you just need to be aware of your sodium intake and understand that your body weight is going to. Follow it. If there are periods of high sodium, expect weight to go up, low sodium, expect weight to go down. And so if your day to day diet contains fluctuating levels of sodium, usually because you are not eating more or less the same foods every day, sometimes your meals are heavily salted, sometimes they’re not salted, sometimes you’re eating in restaurants, sometimes you’re not, etc, etc.

Your weight is going to be more variable. Okay, the next weight fluctuation factor to consider is a lifestyle related one, and that is stress. And that’s because too much stress too often can cause chronically elevated levels of a hormone called Cortisol. And cortisol can cause weight fluctuation in a few ways.

One is by directly increasing water retention. So generally speaking, the more cortisol is in your body, the more water you’re going to retain. Two, it can increase the level of a hormone called ghrelin, which causes you to be hungry and to want to eat food. And if you Give in to that, then you are going to be increasing the food weight in your body.

And if you, of course, overeat too much, then you are also going to gain body fat, which further increases body weight. Number three, studies show that cortisol can trigger cravings for comfort foods. You know, highly processed foods that are delicious. Sugar, salt, fat, calories. These foods are easy to overeat, which adds even more food weight.

And. can result in fat gain if there’s a consistent calorie surplus and the high amounts of sodium that are often in these foods just further exacerbates the weight fluctuation. Because as you’ve learned, a dramatic increase in sodium intake can lead to a dramatic increase in body weight. And finally, number four, cortisol can disrupt your sleep.

Too much cortisol in your body. Too often can lead to disrupted sleep, and then that can lower the amount of leptin in your body, which is a hormone that counteracts the effects of ghrelin, the quote unquote hunger hormone that I mentioned a couple of minutes ago. So leptin is the satiety hormone, the fullness hormone, and lower levels of leptin and higher levels of ghrelin means Hunger, and too much hunger too often inevitably leads to eating more food and sometimes to eating way more food, way too much food.

And that is true for everyone, regardless of how committed they are to their fitness. They can only hold out against hunger so long. And so then if you want to minimize weight fluctuations from cortisol, you want to get enough sleep. You want to drink less alcohol or no alcohol. If you can do that, you want to make sure that you are regularly engaging in relaxing activities.

Maybe it’s reading for you or listening to calming music or just going for walks. You want to make sure that you’re eating a nutritious diet. You want to make sure that most of your calories are coming from relatively unprocessed. nutritious foods, you want to do regular exercise, which may seem a bit paradoxical because exercise stresses the body and it causes cortisol to spike, especially if you do a difficult workout.

But that acute spike in cortisol is not bad in that context. It’s good. Actually, it’s desirable. Sometimes that’s what you want is a large spike in cortisol. What you don’t want, though, is chronically elevated. Cortisol levels and one of the many, many benefits of regular exercise of of at least a moderate level of intensity is some of the adaptations that occur in your body, then allow your body to better deal with stress and to generally have lower cortisol levels.

Now, where exercise can become a problem in the context of cortisol is when it’s too much or it’s too intense or the worst, too much and too intense. Fortunately, though, it takes a lot to get there. I’m talking about many hours of high intensity strength training plus multiple hours of high intensity cardiovascular training every week.

And often that alone isn’t even enough. Often you have to also be restricting your calories and even restrict. Getting them severely to try to rapidly lose body fat, but you can get there. If you’re doing too much exercise and you’re not eating enough food, eventually your body is going to get overstressed, and that is going to contribute to the problem of chronically elevated cortisol levels.

So anyway, just know that your body weight can fluctuate because of stress levels. So even if you are getting enough sleep and you drink, let’s say, no alcohol, and you do have a good stress management regimen in place and you eat well, but let’s say there is a couple week period that is just very stressful because of work or family issues or whatever, just know that that Can cause your weight to jump now.

The next factor I want to talk about is exercise and specifically strength training because over the years I’ve heard from many women usually who start strength training newly who either want to lose body fat. Or just want to maintain their current body fat level, but add some muscle, add some muscle definition.

And they have emailed me or DMD me many times over the years, very concerned because they started strength training and their weight shot up. Rapidly, and they weren’t making any major changes to their diet. There wasn’t anything particularly related to carbs or sodium or stress or any of the other things that we’ve talked about so far.

They start lifting weights and their weight jumps up a lot over the course of the first several weeks, and they’re concerned because they’ve indoctrinated themselves to believe. That weight going up equals bad and so then they’re relieved to learn that that is totally normal, totally expected and is a good thing even has nothing to do with body fat and what it has to do with is when you are new to strength training and you start It’s a good thing.

Training your muscles seriously for the first time or the first time in a long time, you are not only going to gain muscle, which is going to, of course, increase your body weight, but your muscles are going to expand and they’re going to hold more glycogen, which I mentioned earlier, and that, as you remember, comes with water as well.

Your muscles are going to fill up very quickly with fluid and gaining new muscle tissue like contractile tissue that takes a bit more time, but increasing the amount of fluid in muscles that can, that can occur very quickly. And it can be pretty dramatic because even a small woman who is starting with strength training still has a fair amount of muscle in absolute weight.

And if she’s following a well designed program that trains all of that muscle, that alone can produce a significant increase in body weight in just the first several weeks, five or ten pounds. Maybe also she’s taking creatine, which she should be and which you should be. If you are doing any sort of strength training, you should be taking creatine.

And at this point, if you look at some of the emerging research on creatine for cognitive health, for example, for brain health, you could probably argue that Everybody should be supplementing with creatine regardless of what they do or don’t do in the gym. But one of the effects of creatine is your muscles are going to hold even a bit more fluid.

Not a bad thing, a good thing actually, but that means a little bit more body weight. And so then, my point is, if you’re new to strength training, expect your weight to creep upward, at least for the first month or two, or even three, if you start in a calorie deficit, so if you start with a fat loss phase, your weight may creep downward, but just know that the weight that you are losing is From the fat loss is being offset to some degree by the weight that you are gaining through the muscle tissue that you’re gaining as well as the intracellular increase in fluids that I just described.

Next up is the menstrual cycle, which influences body weight in several ways. For example, when estrogen levels are up, that can cause a bit more water retention. When estrogen levels are down, that can cause an increase in hunger and cravings for carbohydrate rich foods in particular, which can increase body weight in a number of ways I’ve already, I’ve already discussed.

Research shows that the menstrual cycle also influences how long it takes for food to go through you, to go through women’s bodies, and when it slows down, which is usually during the late luteal phase, that can result in constipation and bloating and just more food sitting in you, which of course increases body weight.

And last, we have alcohol, which can affect weight in a couple of ways. It’s a diuretic. So short term, it increases urine production. So weight can go down depending on other factors, of course, but it also tends to make people eat too much and sometimes aggressively overeat and especially fatty, carby, salty foods.

Which can more than offset any diuretic effect. Okay, so those are the most common major factors that cause weight to go up and down, that have nothing to do with body fatness. And all that then begs the question, which is, how do you best go about tracking Your body weight. Well don’t do what many people do and that is weigh themselves every day and then fret when their weight goes up when they don’t want it to go up or goes down when they don’t want it to go down.

Also don’t do what many other people do and that is infrequent weigh ins. Sometimes on the same days, so let’s say consistently infrequent, let’s say every Saturday morning after using the bathroom or even worse, inconsistently infrequent, just completely random when the spirit moves them to step onto the scale.

And the problem with both of those approaches is they don’t allow you to accurately measure what’s happening to your body composition. Because your weight can be all over the place for any of the reasons that I discussed. And if we’re going to weigh ourselves, we don’t care so much about the weight per se.

It’s not an end unto itself, it’s a proxy for body composition. We care about what’s happening to the amount of muscle and the amount of fat when we say that we want to lose weight. What we’re really saying is we want to lose fat and not muscle. When we say we want to gain weight, what we’re really saying is we want to gain muscle and not fat.

And tracking body weight correctly is a useful tool. It is not the end all be all, but it is smart to do. However, You have to do it correctly. You have to do it in a way that allows you to consistently measure what is happening to your body composition. And again, if you’re only weighing yourself once per week, you’re at the mercy of those days.

What if on your weigh in day, you’re up five pounds over the day before because you had a very salty dinner and a very carby dinner, or maybe even a salty or carby day the previous day. You gained no body fat, let’s say, but you’re holding now five pounds of water. And so you weigh yourself, and then you curse the scale, and you curse the gods, and this has happened too often.

Next thing you know, you are on the carnivore diet. So, how do you weigh yourself correctly, and how do you avoid those problems? You work with averages, specifically weekly averages. So, every day, first thing in the morning, naked, after using the bathroom, before you eat or drink, you weigh yourself. And then, every seven 10, even 14 days, depending on circumstances, you add up your daily weights, you divide the sum by the number of days and you have your average for that period.

Again, it could be a seven day week, it could be a bit longer, 10 days, or even two weeks. And then you track the The averages over time. You see where the averages are trending. If they’re trending upward, you are gaining weight. Hopefully it’s mostly muscle. There’s probably some fat in there because that is basically unavoidable.

Unless you are brand new to weightlifting. If the trend is flat, you are doing a great job just maintaining your body weight, hopefully maintaining your body composition, and if your weight is trending downward, if these average. Calculations are trending downward over time. Your weight is going down.

Hopefully that means that you are losing fat and not muscle. And one other tip for women is when your weight is most variable because of your period that that week or so of every month when you see a dramatic increase in body weight, just don’t even bother. Weighing yourself. Don’t even bother recording that data.

It is useless. Just weigh yourself every day and record your weigh ins on the three ish other weeks of every month. Well, I hope you liked this episode. I hope you found it helpful. And if you did, subscribe to the show because it makes sure that you don’t miss new episodes. And it also helps me because it increases the rankings of the show a little bit, which of course then makes it a little bit more easily found by other.

People who may like it just as much as you. And if you didn’t like something about this episode or about the show in general, or if you have ideas or suggestions or just feedback to share, shoot me an email, Mike at muscle for life. com muscle F O R life. com. Um, and let me know what I could do better or just, uh, what your thoughts are about maybe what you’d like to see me do in the future.

I read everything myself. I’m always looking for new ideas and constructive feedback. So thanks again for listening to this episode and I hope to hear from you soon.

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