So, I've started a weight loss plan 2 months ago and I'm steadily losing weight. However, I usually gain 1-2lbs over a week, then suddenly shed 3lbs overnight. This cycle repeats itself.

I weight myself first thing in the morning before I shower. Typically, the weight loss happens on either Fridays or Saturdays. I tend to eat out of Fridays as a cheat meal.

My assumption is that this is water-weight building up over the week and then it disappears at the beginning of the weekend.

I'd like to know what could be causing this pattern? I don't see anything wrong with it; I don't expect weight loss to be linear. However, during the week I often find myself thinking I should be cutting more calories, which I do not.

Additional info:

  • I work out 6 days a week, Sunday-Friday.
  • I eat about 2450 cals per day.
  • I drink about 2-3L of water during my work day (7-3) after which I slowly drink less outside of my workout.
  • I skip breakfast (I'm just not hungry)
  • During work days, I eat at the cafeteria at work (600-1000 calories depending on what is offered)
  • Dinner varies a lot, but usually carbs and proteins.
  • Protein shake if I didn't achieve my calorie count

After reviewing my food log, I notice that it is mostly carbs and proteins. Pretty close to what MyFitnessPal recommends me.

  • Can you give me an idea of what foods your diet consists of ?
    – 0xMert
    Jun 8, 2016 at 12:35
  • Yes, I have food logs and I will edit the question in the afternoon.
    – Yousend
    Jun 8, 2016 at 12:40
  • 2
    Its probably your body reacting to the pattern of eating that differs over the week and the weekend .. such as (sorry world) bowl movements probably differ and so you build a bit of a backlog, and then friday... you let rip
    – BugFinder
    Jun 8, 2016 at 14:57
  • Yes, after thinking about it, I do see a pattern in the way my body reacts to different movement.
    – Yousend
    Jun 8, 2016 at 20:58
  • Have very similar pattern, spike on weekend, and drop during week, but for me it drops more gradually, every day consistently, and then hopefully lower than previous week. Yes like clock work.
    – Andrew
    Sep 1, 2017 at 17:19

5 Answers 5


Learn to choose your data

Yeah, you shouldn't place too much value in everyday weight measurements, because they are too impacted by small factors like how much water you drank with your last meal, second servings, how much you pooped/peed today, and an array of other petty things.

What you should do is keep measuring every day, but instead of looking at each measurement, calculate the average over a week, and instead keep track of those averages. That way, your calculations aren't as impacted by the small stuff.


Monday: 85.6

Tuesday: 85.2

Wednesday: 85.0

Thursday: 87.2 (because you ate a particularly large dinner.)

Friday: 86.3

Saturday: 85.9

Sunday 85.1

Average of week 1: 85.8

Notice how this average doesn't fool you into believing that you belong at 87kg+. Weighing 87+ was just a momentary thing, and doesn't matter in the long run.

  • Yeah, I do know to use the average. What boggles my mind is that this pattern is like clockwork. (Sun-Sati: 232.2, 232.4, 232.8, 233.4, 233.6, 231.2, 231.4) My scale is only accurate to 0.2lbs, hence the even decimals. I do take the average, but I always thought that weight loss was irregular but with a downward trend. Mine looks weird and I'm curious if this particular pattern is common.
    – Yousend
    Jun 8, 2016 at 12:39
  • 1
    I'll routinely gain 2+ kg (4.4+ lbs) over the weekend, then lose it all within two or three days and end on Friday at a lower weight than before. The weekly average is a downward trend. My take on it is also that it's mostly water weight because I eat a lot more carbs over the weekend. However, I also suspect that a "refeed" staves off too much metabolic adaptation, keeping weight loss after it solid and easy. I honestly believe you're seeing a marker for success with your fluctuations if the average goes down over weeks. Even if some weeks it slightly rises.
    – G_H
    Jun 8, 2016 at 12:51
  • Yeah, that's completely normal @akadian. It's not just the things you eat, but the things you do. Could be anything from taking a different route home from work, to having a slightly different mood on fridays. Like I said, small factors in life show up on day-to-day measurements of weight.
    – Alec
    Jun 8, 2016 at 13:54
  • Slightly different mood on Friday may not be that small, haha. Fridays are my favourite workout day. Got to get that pump before going out!
    – Yousend
    Jun 8, 2016 at 21:00
  • Yeah, moods have a lot to say. Especially stress is often blamed for people gaining weight.
    – Alec
    Jun 9, 2016 at 16:42

I will also edit my answer once you post your food logs, but this is actually pretty common and there is a pretty clear and well-studied conclusion here. Obviously, I can't 100% be sure since I haven't seen your diet, but you say your cheat day is on Friday and that over the weekend you gain weight. Well...this is pretty expected, happens to me all the time during contest prep.

What's happening is your manipulating your glycogen stores via carbohydrates or excess calories during a single day. Think of your glycogen stores like little balloons that hold water (more accurately, promote water delivery and holding onto them), except instead of air blowing up the balloon, in this case it is carbohydrates and in some cases if you don't eat much carbs, it is due to excess calories from other sources (your body can turn other macros into glycogen). Glycogen is simply just an easy access tank of energy that your body has access to. When you're in a caloric deficit and your carb intake isn't too high, these "balloons" start losing volume and therefore weight, but just like a regular balloon...you can still blow it back up.

It has been proven in various studies that the difference between max glycogen levels and min glycogen levels can vary up to 7lbs!!! The exact amount does depend on the individual's genetics and insulin sensitivity however.

The fact that you don't work out on saturdays also confirms/strengthens the fact that your glycogen stores will be fuller than usual and hence you will be holding more weight. Try this for an experiment, have a really hard workout on saturday (legs if you don't fear death), and weigh yourself Sunday morning (glycogen manipulation does take time), see if this is still occuring...I can almost guarantee it won't, at least to the same extent.

Moreover, note that excess sodium can also have the same effect of holding water. So if, on your cheat days, you eat a lot of fast food and processed foods (which have higher sodium than most foods), then this sodium will also make you retain more water. Combining this with glycogen manipulation, these two can lead to some large fluctuations, so just be aware. Lucky for you (and me), weight/fat loss seems to not really care about a few days, and the process usually depends on your overall weekly calories

EDIT: I just looked into this a bit more, and when I said above that glycogen manuplation does take time, I should specify that it can take upto 2-4 days depending on a lot of factors. Until that time, the combination of excess carbs and proteins will reduce release of body fluids, so once there is an impulse in these amounts, your body will get confused and release a lot of water through urine, sweat, even air through CO2, and thus this is yet another effect for fluctuating weight. This is because since you just cheated, you increased your blood sugar more than usual and thus reduced your cortisol (the most evil hormone to ever exist for muscle building) by a considerable amount, so your body stopped holding on to water for a brief time, had your glycogen stores been depleted, this wouldn't have had nearly the same effect.

  • The OP loses weight on the weekend. Your answer says they gain weight over the weekend.
    – jpmc26
    Jun 9, 2016 at 1:07
  • @jpmc26 you're right, I misread the question, hence why I added the edit at the end.
    – 0xMert
    Jun 9, 2016 at 1:08
  • Corrections should generally be worked into the whole answer, rather than tacked on the end. =) The edit history is public, so no need to worry about preserving what the answer previously looked like.
    – jpmc26
    Jun 9, 2016 at 1:10
  • @jpmc26 yeah true haha, it's just that my previous points are also important to understand so I didn't want to erase
    – 0xMert
    Jun 9, 2016 at 1:12
  • Most insightful. If I have a significant cheat weekend w/ no exercise i might be up ~7lbs by monday, 4-5 days of healthy eating & exercise im back to normal, and then 1-2 to lose weight. Have had the pattern for months. Seems to keep me sane. Dont know if it's healthy.
    – Andrew
    Oct 20, 2017 at 16:44

Typically water/carb weight swings are much larger than fat-loss.

This sounds like water-retention cause by Cortisol caused by calorie-restriction in the week, which is dropped when you "cheat" on Friday night.

See http://www.leangains.com/2010/01/how-to-deal-with-water-retention-part.html

Half-way through the study the men were allowed a relief dinner to celebrate their progress. One big meal of 2300 kcal was served; roasted chicken, potatoes, gravy and strawberry shortcake. That night everyone got up more often than usual to urinate. The next day they discovered that they had each lost several pounds.

Water-weigh changes can also come from changes in Glycogen, but that would have the opposite pattern of what you describe.


Weight is a terrible indicator of general health. In reality it's just 1 piece of the puzzle, and a very misconstrued one at that.

What has weight? Bones Muscle Water Organs/rest of your parts Fat

The problem is fat is a very tiny portion of this (under 10% let's say), and if you're exercising, muscle ends up weighing more than fat anyway so people who are focusing on building muscle will actually gain weight. Significant losses in weight over time are sometimes related to osteoporosis/bone degrading or other major body issues.

You really don't gain/lose much weight eating unless we're trying to split hairs. Your diet can influence how much water your body holds however. (salt intake)

Case in point--scales lie, a lot. For instance, many people don't realize it, but when men loosen a belt later in the day--it's because the waist expands after standing/being upright most of the day. Even your feet slightly change size throughout the day.

  • I realize that, that's why I'm going with the trend. I just found it odd that I had this pattern.
    – Yousend
    Jun 8, 2016 at 21:01
  • Weight might not be an excellent one-off indicator of "health", but weight is a good indicator of one of most people's health-goals - weight maintenance or loss. :P Of course measurements/a mirror are also useful.
    – Andrew
    Sep 1, 2017 at 20:47

If you are using a FitBit or Withings scale (or just tracking your weight on the FitBit site) you can use the TrendWeight site to track your weight. It will help you smooth out your daily weight fluctuations and gives you great insight into what your fat mass and lean mass are doing.

I find that during some periods I am not losing weight but I am gaining lean mass and losing fat mass instead.

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