Rapid Water Weight Loss Well Into Dieting

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I recently had an almost 2 week long plateau where I was exercising basically every day. (I was around 94 lbs lost at this point or 221 lbs) Then, I think I either injured my arm or a nerve got pinched (it's been bothering me for weeks now so I have no idea what's wrong) and I had to quit exercising to be safe.

Over the last week, I have lost over 5 lbs and I'm half elated because it puts me back on schedule for where I was before the plateau, but I'm also terrified that 5 lbs is a lot to lose in a week. I've been eating at around 800 calories under my TDEE calculation which is 1500 calories a day. I'm a rather tall man, so I'm not interested in going below 1500 for health reasons. (But I also recognize I should PROBABLY be eating more. I just really am tired of being overweight and 1500 hasn't felt like a terrible imposition. I don't feel like I'm starving myself.)

I guess my question is, is it possible to lose this much water weight all at once or should I be worried? It's not like I've changed my diet or anything.

Replies

  • Lietchi
    Lietchi Posts: 6,281 Member
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    With frequent exercise (especially resistance training) your muscles retain extra water. So you may be losing some water weight from not exercising.

    Losing 5 lbs in a week doesn't have to be worrying, unless it becomes a trend that continues the next few weeks.
    I will say though that 1500 sounds low, I ate more than that as a 5ft5 woman starting my weight loss journey at 205lbs. You're tired of being overweight, but I presume you'd prefer to lose fat, instead of muscle 😉
  • Speakeasy76
    Speakeasy76 Posts: 961 Member
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    I have "lost" four pounds in a week even while maintaining as a 5'8 45 year old woman with an average weight of 135.

    I agree that 1500 sounds low, and even when I was about 10 pounds heavier I never ate that few calories on purpose. The lower you go below your TDEE, the more muscle mass you will probably lose along with fat.
  • SnifterPug
    SnifterPug Posts: 746 Member
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    Crazy fluctuations are not unusual, especially in conjunction with any significant changes (in your case having to stop exercising for a while) so I wouldn't worry about it unless the drastic loss carries on and becomes regular. I also think 1500 is on the low side but as you're not exercising right now, and not feeling hungry, then it's fine for a while if you need the mental boost of the change in scale weight.
  • earlnabby
    earlnabby Posts: 8,171 Member
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    I recently had a "whoosh" of 4 lb. Why? Our weather has changed from hot and humid summer weather to cool autumn weather. The extra water I retain all summer finally left my system.

    In other words, the human body does weird things at times. Keeping a rolling 4 week average loss (or using a weight trend app) will keep things in perspective and balance out the weirdness that happens.
  • AnnPT77
    AnnPT77 Posts: 32,735 Member
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    That's about 2.3% of your weight overnight. I see that kind of percentage drop fairly often, even in maintenance, though for me it would be around 3 pounds drop, at around 125 pound bodyweight. Experience suggests I "gain" about 2 pounds when I resume strength training after a longer hiatus, and lose that again when I stop.

    I I've had a weight drop as big as 6 pounds overnight, 137 to 131. At the time, I was holding steady in the lower half of the 130s pounds, though I've since intentionally lost a few more pounds slowly. Details about that 6 pound drop, in a thread that includes some other people reporting big-drop experiences:

    https://community.myfitnesspal.com/en/discussion/10679961/this-never-happened-before-fun-with-weight-fluctuations#latest

    (P.S. I also lost most of my excess weight, almost a third of my bodyweight in less than a year, at 1400-1600 plus exercise calories, so often eating around 2000 calories, sometimes more, as a 5'5" then 59/60-year-old woman. I admit I'm a mysteriously good li'l ol' calorie burner for my demographic, but it's good to keep in mind that fast loss increases health risks. Your TDEE calculation isn't the most relevant indicator: What's relevant, once you have 4-6 weeks of solid calorie/weight data, is your actual average loss rate. It's a rare thing, but MFP estimates my calorie needs about 25-30% low. It can estimate low, or high, though it's close for most people. Experience will give a better indication of actual needs, in context of one's logging accuracy.)