How much a constant weight person varies day-to-day

Hi everyone
Here are the results of my weighing every day experiment. I hope they help you!…

I have so many communications with people who say they’ve gained or lost a pound overnight and they are either pleased or upset and I advise people NOT to weigh every day because natural variations in the body’s weight are so common, that you are not getting an accurate picture. The best option for weighing is once a week – at a regular time of day and, ideally, naked. If you have not lost as expected, try weighing again the next day to see if this was a short term variation, but weight loss should only be even close to accurate from one week to the next.

To illustrate how much someone of even normal weight – not on a diet – varies, I decided to weigh myself every day for a month. I have been 7.12-8 stone for c. 15 years and therefore consider myself a pretty constant weight. When my beloved cat died I lost all interest in eating for a few days and dropped to 7.9-7.10 and then returned to 7.12-8 stone as soon as we got another rescue cat and I fell in love with him. Andy and I went to Jamaica for our wedding/honeymoon and the resort happened to be holding an epicurean food festival at the same time. What luck! I ate some of the best food I have ever tasted in my life, didn’t worry much about keeping fats and carbs separate and returned home a couple of pounds over 8 stone and then returned to normal within a couple of days. This is the whole principle of the natural weight – something that your body naturally tends back to.

So, here we go! (I have a set of Tanita ‘serious duty’ scales – for clients – so this is as accurate as I can get. All dates are for September to October 2009):

Thur 17 September   7.13.0 (last day of my period)
Fri 18 September   7.13.4
Sat 19 September   7.12.4
Sun 20 September   7.13.6
Mon 21 September  7.12.6
Tue 22 September   7.13.2
Wed 23 September  8.00.0
Thur 24 September   7.13.8
Fri 25 September   7.13.8
Sat 26 September   7.13.0
Sun 27 September   7.12.6
Mon 28 September   7.13.2
Tue 29 September   7.12.6
Wed 30 September   7.11.8
Thur 1 October    7.12.2
Fri 2 October    Away – sorry – there’s never a month when I’m not away for a couple of days
Sat 3 October    Away
Sun 4 October    Away
Mon 5 October    7.13.2
Tue 6 October    7.13.8
Wed 7 October    7.13.2
Thur 8 October    7.12.8
Fri 9 October     7.12.4
Sat 10 October    7.13.8
Sun 11 October    8.00.2 (first day of my period)
Mon 12 October    7.13.2
Tue 13 October    7.12.8
Wed 14 October    7.12.4

Extra test on one day:
On Thur 8th October, I braved the cold weather (in the interests of research!) to strip off every 2 hours, to show what happens during the day:

7am 7.12.8
9am 7.13.4 (after breakfast and going to the loo!)
11am 7.13.2 (had another large decaff coffee after breakfast, but wee’d lots too)
1pm 8.00.2 (after lunch – the food weighed c. 1lb)
3pm 7.13.6 (lots of water/decaf coffee and wees in the afternoon)
5pm 7.13.4
7pm 8.00.2 (after dinner – c. 1lb of food again)
9pm 7.13.8

There was only one occasion when, by sheer fluke, my weight was the same 2 days in a row (24-25 September).

The lowest weight could possibly be ‘explained’ by the day before being unusually warm and sunny in the UK and I worked on my PC outside and could have dehydrated a bit.

The highest (non time of the month) weight is likely explained by me going to a black tie event on Tue 22 Sept and the veggie option was a pie – no kidding! About half a kilo in weight, this thing was the size of a normal dinner plate (there was no room for veg at all) and it was a white flour, pastry pie filled with cheese and spinach. The calorie/energy content was probably 1000-1500 calories. It was only moderately tasty but I ate the whole lot because I was hungry – after all the speeches we didn’t get scoff until after 9pm. I probably still had most of this pie in me when I weighed the next morning!

A woman’s hormones fluctuate more in a month than a man’s do in a lifetime! Hence we do vary at different times of the month – hormones affect water retention, appetite and all sorts. I don’t know a single woman who doesn’t ‘gain’ 1-2lbs, or more, just before her period and I am no exception. It drops off within a day or two or starting – that’s just part of being a woman. We get shoes and multiple orgasms so, hey ho!

The average weight, across the whole month, is 7.13.0. In the books I say that my weight is 8 stone (nice round number). I am more typically 7.12 – 8 stone, as the above shows, so the average weight during the month is bang in the middle of this range. The variation from this is + or – 1lb. This is less than a 1% fluctuation in a month (and it’s similar every month, every year and has been for years now). I think this is remarkably constant, but some of you see similar fluctuations in your own weight and tell me you’ve gained or lost a pound. I really hope this helps show that you haven’t.

Are these fluctuations normal? Absolutely! The scales (good as they are) are probably not that accurate to start with (I did learn something I didn’t know – the scales don’t bother with odd numbers for fractions of pounds. It’s always 13.2 or 12.4 or 11.8 etc – never 12.7).

What drives them? Quite simply – food and drink going in and waste products going out. The daily recordings (Thur 8th October) show how you can eat a good size meal and gain 1lb (because you have put 1lb of food into your digestive tract) and then ½ lb has gone in fluid extracted by the body from this food even a couple of hours later.

Did I feel any different on the highest and lowest days? Not at all during the month – none of my clothes felt any different (all this food in and out stuff is taking place largely in the digestive tract and that has no impact on the waistband). I felt a bit dopey after the white flour pie and the late night, but felt completely ‘normal’ again after a healthy breakfast. I do feel a bit different just before my period – I am aware that I am holding water on my thighs and boobs and really close fitting clothes can feel a bit too snug, but it comes and goes so quickly.

Moral of the story?
Don’t weigh yourself every day!

Please don’t take into account half pounds and 0.4 of a pound etc. This is anorexic style behaviour and doesn’t fit with having a healthy and balanced attitude to food and weight. Please don’t be that obsessive – it makes me want to hug you and say “start living your life, not recording your weight to within an ounce!

Don’t panic if you ‘gain’ a pound – if you are following the ‘rules’ of The Harcombe Diet, you are so unlikely to have actually gained weight – this will be normal fuel and waste product ins and outs going on in the body.

Be prepared to plateau on any weight loss journey. The idea that weight loss follows a predictable formula is complete and utter nonsense (but you know that or, following a c. 1000 calorie a day diet, an average woman should lose 104 lbs each year, every year, year in, year out! That’s 7 stone 6lbs every year. Most of my clients are trying to survive on 1000-1500 calories a day and haven’t lost a single pound in years – the “to lose 1lb of fat, you need to create a deficit of 3500 calories a day” is a fairy story – and you know it.

Hope this helps!
Zoe x

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Website Comments

  1. avatar Mary

    Hi Zoe,
    I have done really well following your 3step plan. I have also recommended it to others, who have been successful. I was 9st 7lb now 7st 10lb in 6months.I found the principles were a result of me managing to lose weight.
    What advice can you give a 14year old that is over weight, especially around her middle. She has had advice from a nutrionalist to follow the eat well plate. I know you are really busy but I wondered if you could private email me.


  2. avatar Sara-Jane Thalmessinger

    I have just completed the 5 Day Phase 1 stage. Overall I’m happy as I feel much slimmer. The only downside for me is making do without sweetener in tea, have found that very difficult. Also I feel quite sick especially first thing in the morning. Throughout the day I also experience a light headed feeling and nausea. I am onto Day 3 of Phase 2 and enjoying some fruit! I can only assume that as the toxins leave my body perhaps that is making me feel ill> I look forward to your advise.
    thank you

  3. avatar Vyvienne

    Can I eat Sweet Potatoes, Plantain, Avocado, & Olives on stage 1 of the Harcombe diet? My staple nutrition plan only includes fresh fruit, fresh veg, chicken, fresh fish, nuts & seeds. The 1st stage of your plan states up to 14ibs weight loss. Can I expect this kind of loss if I just cut out the fruits & nuts? The 1st time I tried HP1 I did it 4 3 & a 1/2 days & lost 7 & a 1/2lbs. There after every time I’ve done it I’ve only managed 3lbs. Y is that? I am now being knockd sidways by the side effects of chemo. But God is soooo gd. 2 all intents & purposes I am doing v well. However, since I bgan chemo I’ve gaind 2 & a 1/2 stones. U’r supposed 2 lose w8 on chemo, but bcos I have restricted mobility due 2 a dislocated, fractured & broken ankle sustaind from an RTA in Dec ’09, I can not exercise. Will HP1 still b effective in my present condition?

    • avatar Andy

      Hi Vyvienne,
      we now run a help forum for all personal dietary questions over at
      You’ll need to register (it’s free) and then you can post any personal questions you may have. There’s a great support team to help you out
      We look forward to seeing you over there.

  4. avatar Rebecca

    I have been doing this diet since January and have lost 9lbs so have reached 8st 7lb, which is great. I didn’t have much to lose but didn’t want to reach 40 feeling flabby. My target weight is 8st 5lb (I am 5’1″). However, the most frustrating thing is, I can stick to the diet all week and allow myself a few glasses of wine and one meal that follows phase 3 principles on a Saturday and Sunday and when I weigh on Mon am, I have gained 5lbs – its a regular thing. I have chatted to my friends doing the diet and they don’t seem to suffer the same problem. I find it so easy to get back to 8st 11lb without really trying. I feel so disappointed as I want to be 8st 5lbs so if I gain a few pounds, it’s not a problem.I feel stuck in a vicious cycle. I should be able to be on phase 3 without it causing weight gain. I am not cheating too much or kidding myself, I just need advice to reach my goal. Thank you

    • avatar Zoë

      Hi Beccy – please check out our new club, as I don’t check these blogs very often any more. – no moderator needed and about 2000 people will be ready with an answer in seconds!

      There can only be one reason for gaining 5lbs overnight (and we’ve all done this and wondered how is it possible). Whatever carbs you have had will be behind this – refined or otherwise. All you have done is ‘carb loaded’ in effect – you have filled up your glycogen store room (the form in which we store carbohydrate in the body) and, for every gram of glycogen c. 4 grams of water get stored with it. You can hold c. 100g glycogen in the liver and 250-400 grams in the muscles. Hence you can gain up to 500g plus 2kg in water – there’s your 5lbs!

      You are either more carb sensitive than your friends or they ‘cheat’ with different things. I cheat with dark chocolate (loads daily) and hubby cheats with red wine, but neither of us cheats much with even lovely bread and whole wheat pasta – they’re just not worth it. Any wheat and I’m bunkered the next day – you may be similar.
      Hope this helps and hope you like the club!
      Ciao – zoe

  5. avatar Zoë

    Hi David – thanks so much for the update. I started a private email to you, as I hate to see anyone not doing well, and then I got caught up in trips to London, writing, researching and all sorts – I’m so sorry!
    I’m also puzzled why you a) didn’t do well first time in Phase 1. You would have been a rare ‘failure’ and we don’t want those! First thought with women is always ‘time of the month’ (we hold water and then it falls off and we see what we actually lost in Phase 1). First thought with men would be constipation – any change of diet (even to all healthy stuff) can cause a change in regularity and, again, you can be losing and it doesn’t register. Second thought was overdoing the NLY and taking in more carbs than you personally were OK with (carb sensitivity).
    I’m really pleased to hear you’ve had subsequent success and hope this continues. You are at the top end of normal weight, so you don’t have much to lose. Hopefully very little more after a couple of successful weeks!
    The one overriding thing I have learned about weight loss is that there is no formula, no 2lbs a week if you cut 1000 cals a day (this is a big part of my next book) and it has been so wrong that we have perpetuated this myth. I have come to see that weight loss is as much about the body stopping the storage of fat as it is about the body burning fat and the body will only do the former when it knows you are out of a starvation situation. Your body may have just taken a bit of time to let go of the fat stores that are there, in evolutionary terms, to keep you alive! Smart body!
    Good luck getting to target
    Very best wishes – Zoe

  6. avatar David J. Gregory

    Hi Zoe

    Update on my previous post …

    Wow – repeating Phase 1 led to a weight loss of 7lb in one week! None of the symptoms I reported in my first week reappeared; I continue to feel great with no hunger or cravings. To say I’m not quite as despondent about the diet as I was, would be the understatement of the year.

    However, assuming no underlying medical conditions, I can still find no explanation as to why my weight didn’t fall at all during my first week of Phase 1.

    Anyway, needless to say I will be continuing your diet and I’m really looking forward to getting back on the scales at the end of this, my first week of Phase 2.

    Thanks and regards


  7. avatar David J. Gregory

    Hi Zoe

    I’m now approaching my mid-40s and my weight has been steadily increasing as I’ve got older. I’m now 13st with a BMI of just over 25. I look and feel overweight.

    I’ve tried several diets in the past without any significant weight loss. I read your first book and what you said really clicked with me – “Here is someone who finally makes sense so I can really lose weight”, I said to myself.

    I started Phase 1 two weeks ago and it was an extremely tough week. I didn’t feel hungry or suffer cravings but I did suffer with headaches, joint pain and the shakes. I put this down to caffeine withdrawl (I was a big tea drinker) and/or candida die-off (addicted to bread products). By the end of the week my symptoms had gone but, unfortunately, my weight had not changed at all (measured at same time of day).

    I’m repeating Phase 1 again this week. No hunger, cravings or symptoms (in fact I feel great) but I’m still not losing any weight despite sticking to the diet plan religiously (no cheating at all!). Any ideas why this would be?

  8. avatar Zoë

    Hi Sam – I’m so sorry but this is the kind of detailed query that would require a consultation, rather than a blog answer. I’ll try to set up some ‘surgeries’ soon for shorter queries, but I’m just frantic on some other ‘must-do’s’ at the moment.
    I can say that it will be carbs affecting weight loss and not fat/proteins, so manage your carb intake every time to speed things up!
    Thanks for your understanding
    Best wishes – Zoe x

  9. avatar Sam Garner

    Hi Zoe,

    A colleague recommended I try your diet after I complained about constantly losing weight on low fat diets, and then putting even more back on, over the last few years.
    I’m 5ft4 and was 12st4 when I started your diet two weeks ago. I lost 4 pounds during phase 1 (which I did for 7 days), and have really enjoyed the fact that I never feel that starving, shaky feeling like I’m going to faint any more unless I have food. I never feel bloated after meals, and because I’m studying at the moment, I definately feel my concentration has improved. Also – I was addicted to crisps, and could easily eat a few packets in one go before, but have been amazed that I no longer crave them.
    However during my first week in phase 2, I only lost 1 pound – so am slightly disappointed. I know that a pound is better than nothing, but had expected to lose a bit more. I’ve followed the phase 2 rules very striclty, and have been mainly following recipes from your ‘Stop counting calories and start losing wieght’ recipe book, and haven’t been cheating – so wondering what may have gone wrong?
    I’m now starting to think it’s because I ate too much fatty foods?
    I want to stick to the diet, but if I’m only going to lose a pound a week, I know that I’ll find it really de-motivating – please help

  10. avatar Zoë

    Hi Joan – I’m so sorry to hear this. I really do know what it’s like to be heavier than you feel comfortable with – it just gets to you every minute of the day.

    If you are UK based, you can get the books in Waterstones, Borders, WH Smith and independent bookshops – if they don’t have one in stock, they will order one for you. Amazon is generally the cheapest, but not everyone wants to buy on line.

    I hope that eating real food and nothing processed will help with your general health and the thyroid condition may be helped by this (eating well can’t hurt). Hopefully your GP is helping in parallel with any necessary medication. It does take a while to get the balance right, but there is no reason why this can’t be sorted with a twin approach.
    Good luck!
    Best wishes – Zoe

  11. avatar Joan Strong

    I am only beginning to look into your diet. Is it possible to buy your books in a local book shop or do I have to buy them on line? Since giving up work and being diagnosed with an underactive thyroid problem I have put on one and a half stones. I would love to get it off. I have tried weight watchers but it didn’t work for me. I get so depressed. I have always stayed around 8st 2lb – 8st 5lb for years. I now weigh 10st. It is much too heavy for me.

  12. avatar Zoë

    Hi Ali – many thanks for spotting the aubergine dish – I’m working on edits for the next reprint now, so I’ll clarify no mushrooms in this recipe – for the avoidance of doubt!
    No hummus in Phase 1 – it is in the index at the back of the book (2 mentions) but it’s not on the Phase 1 allowed list
    Hope this helps – good luck to the office!
    Best wishes – Zoe

  13. avatar Ali

    Hi, I’ve just bought your book along with half the office! Can I eat homemade houmous or shop bought in Phase 1? I’m also a bit confused as on page 136 of “stop counting calories…” it says that the aubergine boats can be used in phase 1 if I leave out the cheese. It also has mushrooms in it. I didnt think I could eat mushrooms in Phase 1?

    Thank you.


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