Initial diet & water weight loss - question

helaurin
helaurin Posts: 157 Member
in Health and Weight Loss
Hi,

I'm told that generally when a person starts a diet, that at first, all they lose is "water weight" - not actual fat, etc.

How much of that initial loss is really water weight? Is it a general percentage of the person's starting weight? Or is it the weight that the person first loses over a certain number of days at the start of the diet?

For example - I started at about 187 pounds, and in the past 11/12 days, I've dropped 9 pounds. I've also been averaging about 1,350 calories intake per day, and have been hitting at least 7,228 steps each day (some days more) - that's a big increase in activity level for me.

Was ALL of that just water weight, and does that mean I haven't actually lost any actual fat?

I've heard various claims (the first 5% is water, the first 14 days is water, even the first month is water) etc.

What's the scoop?

Replies

  • HeidiCooksSupper
    HeidiCooksSupper Posts: 3,831 Member
    I attribute much of this to the switch to a low-sodium diet. Many checkout counter magazine diets that promise huge weight loss in just a week assume they are switching folks from a high-sodium diet of processed foods to a low-sodium diet of fresh foods and veggies.
  • briscogun
    briscogun Posts: 1,135 Member
    Well, if you've lost 9 lbs in 12 days, if it were all fat then you'd have to have been eating at a daily deficit of 2,625 calories. So there was probably an amount of water weight in there.

    So when I first started my most recent weight loss a few months back, I had gone out on a Sunday to the bar & grill then started my diet Monday. Weighed on Monday for a starting weight. Tuesday I was 3 lbs lighter. I did not eat at a 10,000 calorie deficit on Monday. It was a combination of sodium from Sunday, water weight, carbs, etc, being worked out. Some people refer to it as "The Whoosh": an initial large drop on the scale.

    Don't worry about what is water weight, what's fat, etc. Just focus on being consistent and following the trends. You will NOT be losing 9 lbs every 12 days very often if ever again.
  • lgfrie
    lgfrie Posts: 1,449 Member
    edited November 2020
    If you start a diet and are in a calorie deficit, you will lose fat in accordance with your calorie deficit, and any weight loss beyond that will be water weight.

    So, a simple example. You start a diet that has a 1,000 calorie per day deficit, which is 7,000 calories per week or 2 pounds. A week later you are 5 pounds lighter on the scale. Obviously you have lost 2 pounds of fat, and an additional 3 pounds of water.

    But let's say that instead of the scale showing 5 pounds, it shows 8 pounds lost. Well, you've still lost the same 2 lbs of fat but now you've lost 6 lbs of water.

    Let's say the scale shows zero pounds lost. In this case, you've lost 2 pounds of fat and retained an extra 2 pounds of water.

    There is always a possibility (indeed, a likelihood) that your calorie deficit calculation is a little off. So, for instance, you or MFP or other tool of choice may think your maintenance/"TDEE" caloric level is 2400, from which it comes up with 1400 as the target level for losing 2 pounds per week. That number could be off in either direction by a couple/few hundred calories. So it's plausible that instead of losing 2 lbs of fat, you actually lose 1.7 or 2.3. Very possible. It isn't an exact science unless and until you compute your personal TDEE from 6-7 weeks of good data. But it will be in the ballpark.

    To be blunt, the notion that the first 14 or 30 days is water loss is complete nonsense, as is the notion that the first 5 % or x% is water. Water is not lost as a percentage of your weight loss. And it doesn't take 14 or 30 days to drain off the excess water. It takes 4-8 days for water to rebalance in accordance with your new caloric, sodium, and carb levels, but most of that will occur in the first 2-3 days.

    Based on the #'s you've provided, i.e. losing 12 pounds in 9 days, a good guess is that you've lose 2-3 pounds of fat and the rest is water. It could be 1.8 or 3.5. It isn't an exact thing. But I would put my money on 2-3 lbs of fat lost.

    That said, I agree with a comment above that you should just ignore this for now. Get into your diet, eat a consistent calorie deficit and get some exercise, and the results will come. Scales are great for accountability but not so great for telling you how much fat you've lost in the last week or two.

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