Whenever I write about weight issues, I find that a lot of people in my audience are unfamiliar with the concept of water retention. I believe this lack of knowledge is one of the problems when it comes to weight control. A large percentage of your body is made up of water, and it is able to store several litres at short notice. Normal daily fluctuations in weight due to water can easily amount to plus or minus 3 kg, and considerably more in extreme cases (up to 5 kg or more).
One kilo of fat tissue corresponds to about 7000 kcal. A person of average height and weight burns around 2000 kcal a day, and a calorie reduction of 1000 kcal per day will lead to a loss of about 140 g of fat daily.
That works out to about one kilo of fat lost per week. The problem is that this amount of weight loss is well within the range of natural fluctuation due to water. So a person can easily eat very little for three days and lose half a kilo of fat, but also retain a litre of water in that time. When she steps onto the scales, she’ll think, ‘What? I’ve barely eaten for three days and gained half a kilo?!’ On the other hand, it’s fairly typical for people to experience losing several kilos in weight very rapidly at the start of a diet thanks to water loss. The car- bohydrates our bodies store for short-term energy supply bind a large amount of water. The dieter’s body will consume these energy stores first, before it starts burning fat reserves, which means a large amount of water is ‘released’.
However, that water is retained again by the body as soon as the dieter eats enough to restock those short-term stores. This is one of the origins of the myth of the so-called yo-yo effect.
Real weight loss can only be recorded by measuring weight over a long period of time, rather than from one day to the next. After a whole day of really pigging out, it could easily happen that your scales show a drop in weight, simply be- cause your body has lost some extra fluid for hormonal or other reasons.
Or vice versa. So one day means nothing in isolation. Possible causes of small-scale fluid fluctuations include those listed below:
water your body retains;
toms like swelling or tenderness in the breasts, bloated belly, etc.);
muscles, which leads to swelling in those muscle areas;
weight loss of a few kilos due to dehydration. Larger fluid fluctuations may be due to the following:
the contraceptive pill;
It is important to be clear that these kinds of fluctuations due to fluids are not real excess weight.
Someone who gains a kilo due to fluid retention is no more overweight than someone who gets on the scales wearing a thick winter coat. It might be annoying, but it’s not a reason to panic and suddenly start dieting. On the contrary: a diet in that circumstance could reduce healthy body fat values to unhealthily low levels, leading to being underweight when the fluid retention abates.
One way of telling whether extra weight is because of fluid fluctuations or due to fat storage is by looking for pressure marks on the skin, for example from trouser waistbands or socks — fluid in the body’s tissues leads to these marks. Very rapid weight gain is also a sign of water retention.
A person who ate twice their normal daily amount would only put on around 300 g per day. So if you find yourself gaining several kilos within a week without having increased your eating considerably, the most probable cause is fluid retention.
If you experience sudden, extreme water retention, you should be seen urgently by a doctor, who will test whether it is caused by illness or a lack of certain nutrients. This level of fluid retention definitely should not be treated with diuretics (drugs
which increase the excretion of water) or by dietary means without medical ad- vice. In my view, what follows is a typical development of a diet. Person X decides to finally start doing more exercise and eating less. In the first few days, her carbohydrate stores are used up, several litres of water are ex- creted, and the scales show a weight loss of 2 to 3 kg over the next few weeks. Person X is pleased — It is possible! I’ll keep up the good work! — and continues to exercise and eat less. Physical exercise causes tiny rips in person X’s mus- cles, increasing the body’s need for protein in order to repair itself. But person X’s diet includes mainly fruit and vegetables as they are seen as healthy.
This gradually leads to a protein deficiency. This deficiency and the fluid retention it causes mask any loss of fat on the scales, and although person X is exercising and sticking to her diet, she stops losing weight, or even gains a little. Now, along come all the well-meaning people who say things like, ‘Well of course, your body’s in starvation mode now, so it’s holding on to everything it can get. You have to eat more if you want to lose weight!’ So, person X starts eating more again, putting an end to her protein deficiency, and all that retained water is finally excreted from her body.
Although she is now eating more, per- son X does not gain weight, and may even lose a little. Aha! she thinks, I really was eating too little to lose weight. But, having returned to her original eating habits, she slowly begins to gain weight again. ‘Sure,’ her friends tell her, ‘starv- ing your body has wrecked your metabolism. That’s what you get for starving yourself.’ And so, person X is left with the impression that her starvation-metabolism makes her put weight on when she does not eat enough. And she also puts on weight when she eats more. No matter what she does, she can’t lose weight. Person X could have done any of the following, and she would have avoided this scenario:
caloric deficit. Her weight would not have fluctuated so much, and she would have lost weight gradually.
supervision, with blood tests, vitamin supplements, and sufficient pro- tein. She would not have had so much fluid retention, and her increased weight loss would have gone on more or less continually.
nating weight loss. At some point her body would not have been able to retain any additional water. Despite her water retention, her weight would have gradually gone down due to the loss of fat.
Unfortunately, however, very few people follow any of these options. And importantly, option c) is not to be recommended, as prolonged nutrient defi- ciencies can cause damage to the body’s organs, bones, and muscles. Paradoxically, such a protein-deficient situation can even mean that well- intended physical exercise has the opposite to the desired effect and causes a loss of muscle mass. In principle, two conditions must be met for muscle mass to be built up: physical strain on the muscles so that they are stimulated to de- velop, and a sufficient supply of the right building materials, i.e., proteins. Plac- ing strain on muscles causes tiny injuries which must be repaired. If there are no protein materials available for this, the body is forced to break down the damaged muscle tissue. In this way, eating so little that the body no longer has sufficient supplies of protein and doing lots of well-intended physical exercise at the same time can actually lead to muscle mass being lost more quickly than without any sporting activity at all. It could be the case, then, that by reducing her intake of nutrients and doing lots of physical exercise, person X lost muscle mass and further re- duced her energy needs after her diet. I have personal experience of this protein problem, and I am glad to say that by the time it happened to me, I had already abandoned most of my fat logic and so managed to avoid falling into the typical dieter’s trap.
After about six months of only eating 500 kcal per day, my physical condition gradually began to improve enough that I was able to start doing physical exercise. I began with weight training and an exercise bike.
Since I had lost weight continuously and radically during my calorie reduced diet, I thought, If I now burn 500 kcal a day by exercising, I should start losing weight even faster. Wonderful! And that was in- deed the case for the first few days. But then my weight loss began to level off.