Daily Weight Loss Fluctuations:
A Six Month Case Study

December 31st, 2008

Most personal trainers will tell you not to trust your scale. Since bodyweight fluctuates daily, even hourly, many fitness professionals go so far as to use only photographs in gauging progress or disallowing weight measurements altogether. When I set out to lose weight I decided to take a very different approach, determined to truly and scientifically understand how weight loss happens.

Recording my weight and body fat between two and three times daily, I kept the information meticulously stored in an Excel spreadsheet. This information was carefully analyzed alongside other data such as heart rate, activity type, weather conditions, et cetera, to determine the scenarios that resulted in maximum results. One of the most surprising things I discovered was the link between daily weight fluctuations and motivation.

So here, in the interest of spreading useful information, are some of my findings. Charted below is a six month period of time where I shed 20-25 pounds and my analysis thereof.

Legend

1. A. Initial Plateau: It takes time before overcoming inertia and building weight-loss momentum; having lost around 50 pounds and over 15% body fat in total I have reaffirmed this many times. This initial period can be extremely discouraging since despite exercising and eating right you will not see lasting results for months – in this case I was exercising at least three times per week during period A. What you will see is daily fluctuations that give the illusion of progress, only to disappear hours later. Stick with it! In about two months I entered period B, which was much more encouraging.
2. B. Real Progress: After the initial plateau your body realizes it will be dealing with an ongoing exercise regimen and begins to adapt to your new lifestyle by shedding fat and building muscle. Also, at this point you’ve had enough time and experience to figure out the little details that were holding you back. Perhaps you bought new shoes, got a good piece of exercise equipment, or found a friend to exercise with you. Whatever the case may be, this is where you see real results. However, the results come measured over months, not days or even weeks. More on this in items D and E.
3. C. Ending Plateau: After a period of progress you will inevitably hit an ending plateau. It doesn’t matter what type of training it is. This can be caused by changing circumstances that require adjustment of your routine or lifestyle. In the case shown I had started a new job and distractions took my focus off fitness – a readjustment was required. At this stage you mustn’t assume your job is done. Fitness is a lifestyle, not a hobby. Without maintaining at least some of your former routine you are bound to regress.
4. D. Hyper-Progress/Regress Illusion: At various points you will see significant weight loss of almost magical amounts. On August 3^rd I weighed 182 pounds, three days later I weighed 173. Did I truly lose nine pounds of fat in three days? Not at all. If you compare your water-loaded, stomach-full measurements with your dehydrated, stomach-empty measurements you will get seemingly miraculous results that only amount to an illusion. Conversely, depending on your timing you can have some very discouraging results that too are entirely deceptive.
5. E. Reality Shock: At times you will endure a motivational rollercoaster. August 26^th I measured 177.5 pounds, the next day 171.5, the day after that, 177.5 again. Is it possible I lost 6 pounds and regained it in two days? Yes and no. Yes, in that I lost the water and digestive weight, no in that I still had a spare tire and lovehandles.

Main Factors

1. Exercise sweat: Depending on physiology and exercise intensity, you can lose several pounds per hour simply by sweating. In fact, professional fighters commonly undergo extreme dehydration regimens so they are paired with lighter opponents.
2. Night sweat: During the approximately 8 hours we sleep each night, our bodies continue to function, expelling sweat and all. Take a look at the sweat stains inside your pillowcase for proof!
3. Digestive contents: Even a small amount of matter in your digestive system can add significant weight. This contributes to the popularity of colon-clearing systems, despite their results being temporary and doing nothing to reduce body fat.
4. Sodium: High levels of sodium, found commonly in salt and processed foods, can cause excess water retention. Evidence of this is found in athletic drinks which contain significant sodium levels in order to keep an athlete hydrated.

Lessons Learnt

It turns out “weight loss” is too general a title; sure you can lose weight but your self-esteem and health aren’t tied with your gravitational pull. Weight isn’t important, fitness is.

It’s better to focus on your body fat percentage than weight. It’s important to see progress in order to stay encouraged and motivated but body fat should be the metric of choice. Nowadays I have switched mainly to tracking my body fat with weight only used as an afterthought. I use a Tanita-brand scale that quickly provides body fat measurements; no need for calipers or calculations, just stand on it for a few seconds to get your results. Body fat measurements are affected by the aforementioned factors too, but not as drastically as weight. At most you will typically see your body fat off by one percentage point at a time. Armed with this knowledge you have no reason to be discouraged by the occasional higher reading. Should your body fat go up two points, however, you should consider that a strong warning to get your act together.

A New Low: My favourite way to measure body fat and weight is one I paradoxically call “hitting a new low”. Measuring immediately after exercise sessions, sweat loss results in low readings on the scale, boosting my motivation. I know this is not my true body fat or weight but it encourages me to push myself harder, sweat up a storm and burn a lot of calories in hopes of “hitting a new low” each time. Although my measurements go up as soon as I rehydrate, the loss of calories definitely helps push my trend in the right direction which serves the ultimate goal of fitness all the same.

Forest for the Trees

Trend is the most important thing to focus on when considering measurements. Individual and weekly measurements don’t tell a story, they’re just fallible snapshots. Monthly measurements do a better job, but are still swayed by circumstance. If you are going to keep track of measurements, make them detailed, note their circumstances, focus on body fat, and above all else look at the overall trend.