How Long Will It Take to Lose the Weight?| Updated: May 15, 2019
The Long Walk …
- In perfect conditions – good weather, flat roads, comfortable shoes, and regular rests – you can easily walk for eight hours each day at a comfortable pace.
- According to Google Maps, the walking distance between New York and LA is around 2,800 miles.
- At three miles per hour, it will take you 933 hours of walking to cover this distance.
- With everything going absolutely right, you’ll get to LA in 116 days, or a few days short of four months. That is, if you don’t stop for a day.
Unlike this truly monumental, once-in-a-lifetime road trip, a rather ordinary weight loss journey from 175 to 125 lbs. is measured in fat loss per day rather than miles per hour. To begin, let’s switch over to the metric system first.
You’ll immediately feel better and lighter just by realizing that you are weighing half as much in kilos than in pounds. And losing 100 grams a day also feels like a much greater accomplishment than a mere three ounces. Also metrics will let you do the math without resorting to a calculator.
How long does ordinary weight loss to a normal weight really take?
- The “distance” between your current 80 kg (175 lbs.) and the target 57 kg (125 lbs.) from your youth is exactly 23 kg (50 lbs.).
- In the first two weeks of your reduced calorie diet, you’ll drop 15 lbs. (7 kg) of phantom weight (the subject of a prior post). That leaves you with 16 kg (35 lbs.) more to go…
- Let’s assume that you can stick with a 1,200-calorie diet for as long as it takes to lose 100 grams of fat per day. A total fast, on average, may yield 200 to 300 grams of daily weight loss with about half of it at the expense of body fat. So losing 100 grams daily while still on a modest diet is an excellent rate of fat loss.
- A simple division of 16 kg (1,600 g) by 100 grams results in 160 days.
As you can see, it takes slightly over five months of a rather restrictive dieting to lose 35 lbs. (16 kg) of fat for good. And that is, ideally, with no family to cook for, no parties to attend, a supportive spouse, decent digestive and endocrine health, good sleep, little stress, and an iron will to resist an occasional piece of dark chocolate or a glass of wine.
Let me repeat that: A healthy middle-aged person in a supportive environment may require at least 160 days for losing 35 lbs. of excess body fat on a strict 1,200 calorie diet.
That isn’t exactly what all of those famous diet books have been telling you all along, is it? What have they promised you? Two weeks? Four weeks? A few months? Yesterday? It’s total, complete bull my friends!
If, indeed, these authors were telling you the unvarnished truth the way I just laid it out, most people simply wouldn’t buy their books, take their classes, or eat their snacks and prepackaged meals. Just imagine a tagline on the cover of one of these diet books:
“Struggle through a 1,200 calorie diet for the next 160 days to rediscover the body of your youth!”
Would you? I doubt it. And if your environment isn’t supportive, or you aren’t exactly in perfect health, or you are well into menopause, or you lapse every so often into binge eating, or you can’t give up alcohol, or what have you, it may take even longer than 160 days, much, much longer…
Sorry for being a spoiler, but that’s, ladies and gentlemen, the hard truth of successful and permanent fat loss.
To fail – do as they say. To succeed – do it right!
So, let’s get brutally honest with ourselves and totally technical about the process. As I explained in the previous post, diet-related weight loss has two distinct stages: the loss of phantom weight first, and the actual loss of excess body fat second.
As you recall from that post, the loss of phantom weight lasts up to two weeks and is represented primarily by the reduction of undigested foods, fluids, and stools inside your gastrointestinal tract, but little or no actual body fat.
The resulting weight reduction is often quite profound – anywhere from 10 to 20 lbs., depending on your starting weight, diet, and colon health. This “magic,” however, is over as soon as your scale comes to a screeching halt, even though you are still consuming the exact same diet.
That is why the next stage – the permanent loss of body fat – is what you are re-e-e-a-l-ly after. Its duration depends on a multitude of factors, beginning with the amount of fat you need to lose and ending with your age, height, gender, ethnicity, occupation, rate of metabolism, personality type, the quality of sleep, physical activity, diet composition, climate, and some others.
Estimating the length of an effective weight loss diet isn’t rocket science, but rather elementary school arithmetic. It can be expressed in these three simple formulas:
Excess fat = Current weight — Desired weight — Phantom weight
Fat loss duration = Excess fat / Daily fat loss
Total diet duration = Fat loss duration + Two weeks
Let’s give definition and meaning to all of the above variables:
- Current weight. Purchase the best electronic self-adjustable scale that you can afford, set it to metric mode, and weight yourself first thing in the morning, with no clothes on and after urinating. I personally use the Omron HBF-514C scale because it has a resolution of 100 grams and is quite sturdy and professional looking. For consistency, always use the same scale.
- Desired weight is your target “normal” weight. If you weren’t overweight in your youth, the desired weight is usually your average weight between the ages of 18 and 25. If you were always overweight, the formula for determining your desired weight (in kilograms, not lbs.) is your height in centimeters minus 100 for men or 110 for women. This simplistic method does not account for body morphology and muscle strength, but it is close enough for these calculations. Keep in mind that in many instances your desired weight may be higher than your “normal” weight because a substantial weight loss in your later years may reveal the signs of premature aging, such as facial wrinkles, sunken eyes, shabby neck, or floppy love handles under the arms, so you may want to avoid turning one appearance-related concern into another. That’s why I used the word “normal” in quotes – what may be a norm at 20 may turn into a menace at 40.
- Phantom weight loss is determined during the first two weeks of your diet, as I already explained this phenomena earlier. As big as this figure may be, for all intents and purposes it is nearly meaningless to true weight (i.e., fat) loss, and incredibly self-deceptive to boot.
- Excess fat is the only realistic measure of your weight “problem.” That is what you want to lose, and losing it for good requires the most amount of time. Your excess fat is determined by deducting phantom weight losses and desired weight from your current weight.
- Fat loss duration is the number of days you must remain on a low (or very low) calorie diet until you attain your desired weight. That’s the number you are really after. If you come to this process with unrealistic expectations, you may quit your perfectly performing diet way before it has a chance to prove itself.
- Daily fat loss. To establish this number as accurately as possible, you’ll need to stay on a fat reduction diet (after completing your phantom weight loss, of course) for at least 15 to 20 days, or even longer. There are several reasons behind this requirement: (a) the low resolution of consumer weight scales; (b) day-to-day natural weight loss fluctuations; (c) the propensity of weight loss to slow down somewhat as your body adjusts to reduced calorie intake; and (d) inevitable lapses in your daily caloric intake. To properly estimate your daily fat loss, wait until your weight goes down at least 2 kg, and divide this number (i.e. 2 kg) by the number of days it took you to get there. If you do not observe any measurable weight reduction throughout this period, it means that your diet is too generous for your particular rate of metabolism, and you’ll need to reduce your caloric intake even more. Or you may need to increase your level of physical activity. Even better, do both (i.e., eat less and exercise more) until you observe sustainable weight loss. For as long as you consume less nutrients than your body expends for energy and structural metabolism, fat loss is just as assured as sunrise and sundown – no ifs, ends, or buts about it.
- Total diet duration. This number is self-explanatory. Just prepare yourself for the total diet duration being longer than your most conservative estimate because a real life throws its curve balls, diet or no diet. When it comes to safe and sustainable weight loss, being cautiously realistic always beats being hopelessly optimistic.
Can You Lose the Weight? Easy come isn’t always easy go, unless…
…unless you do it right. So let’s review a real-life example, using my own experience as a base. As you embark on your own weight loss journey, just replace my numbers with yours.
When my family immigrated into the United Sates at the end of 1978, I stood 5’7” and weighted 70 kg (154 lbs.) without an iota of visible flab on my taut body. Up until the very end of medical school, I was actively involved in boxing, bodybuilding, skiing, and hockey. Not surprisingly, throughout those years, I was wearing size 32 pants, 15.5” shirts, 38S jackets, and 9.5 shoes.
My weight and shape stayed the same until I quit smoking in 1984. Soon thereafter I developed constipation-dominant IBS (a pretty common side effect of smoking cessation) and started gaining weight. (Smoking cessation stimulates weight gain not because it may increase appetite in some people, but because it reduces the rate of energy metabolism through the improvements of the lung, heart, and liver functions, meaning these organs need to work less to accomplish the same output when no longer smoking.)
On the advice of my physician, I switched over to a high fiber, dairy-free diet, but it made matters worse. So I kept searching. In the summer of 1991, after reading “Fit for Life,” a vegetarian manifesto by Harvey and Marilyn Diamonds, longing to become as strong as an elephant (a vegetarian, of course) and as fit as Mr. Diamond, I embraced a vegan lifestyle. Guess what? By 1996, at age 42, I was still 5’7”, but now weighing 82 kg (181 lbs.) and wearing size 40 pants, 42S jackets, 17.5” shirts, and 10 EEE shoes. Yes, my feet got elephantine too.
From that point on, it took me four more years of trial and error with various diets to get down to my normal weight. If I had known then what I do know now, that journey would have been significantly safer for my overall health, and a lot shorter. I’ll address the safety aspects in future posts. Meanwhile, let’s concentrate on determining the total diet duration for someone in my predicament at that time, but based on my current knowledge:
To determine my phantom weight, I reduced my daily caloric intake to 1,400 calories. This number may or may not apply to you, and I am using it here for illustration only. I will address stage one and stage two diet composition and energy density in future posts.
At the end of the two week period, my weight dropped to 78 kg (172 lbs.). The loss wasn’t as dramatic because I wasn’t a prodigious eater to begin with. So I ended up with 4 kg (7 lbs) of phantom weight loss and was ready to calculate my excess fat:
82 kg (current weight) — 4 kg (phantom weight) — 70 kg (desired weight) = 8 kg (excess fat)
Not bad, actually. I only needed to lose eight more kilos of fat in order to get down to my lowest adult weight of 70 kg.
To determine the total diet duration, I continued with my 1,400 calorie protocol until I lost another 2 kg (4.4 lb). This stage took me 26 more days.
To determine my daily fat loss, I divided these 2 kg by 26 days (2,000 g / 26 = 77 g).
Now I know that for as long as I’ll be staying on a ~ 1400 calorie diet, I’ll be losing ~77 grams of fat each day, and this is going to take me ~103 days, or about three and a half months (~ symbol means approximately):
8,000 g (excess fat) / 77 g (daily fat loss) = 103 days (fat loss duration)
Please note that those 103 days already include the 26 days I spent on determining my daily fat loss number. So, in fact, I only needed to stick to my 1,400 calorie regimen for 77 more days. Not a problem – I can definitely do that, except I also knew that over the next three months I would be attending two birthdays, one wedding, and six business dinners. Since all of these events will blow my diet somewhat, I added three extra days for each of these nine events, or 28 total.
Thus, if everything went as planned, I’d be back to 70 kg in the next 105 days (77 + 28). Not bad, not bad at all, considering a fruitless struggle over the previous four years.
Even the right diets fail when smart people fail to do them right
So why did it take me almost four years to reach that goal back in 2000? Well, as I said before, I didn’t know anything about phantom weight loss, the slow rate of actual daily fat loss, or a number of other equally relevant issues. No wonder, then, that as soon as the dramatic – half a pound or more per day – weight loss was over, I was quitting without ever really starting.
Even more dispiriting and injurious was that with every failed attempt, I was gaining more and more fat because each unsuccessful dieting cycle reduced the rate of my energy and structural metabolism, which was the complete opposite of what I was trying to accomplish.
I am now a decade and a half wiser and more experienced. Depending on the time of year and the degree of my indiscretion with an occasional glass of sake or wine, my weight swings between 68 and 70 kg, less in the summer, more in the winter. This is normal and expected for anyone living a normal life.
These fluctuations don’t overly concern me because when the scale creeps past 70 kg, I know who to blame (myself, of course) and start adjusting my diet accordingly. And for as long as my weight stays in that narrow range – plus or minus 2 kg – I fit all my clothes and feel great about my appearance.
Ready to diet right? In the next post, “How to Prepare Yourself for Safe and Effective Weight Loss Diet,” I will explain how to drop your phantom weight along with a couple of sizes without encountering diet-crashing side effects such as hypoglycemia, constipation, dehydration, indigestion, hair loss, and many others.
Make sure that people with whom you share your meals review your plans too. This will ensure they do not sabotage your weight loss odyssey with their well-intended but often incorrect advice!
More Information on Weight Loss
Previous posts from the “Why Diets Fail” series:
For your health and safety, please read these important Weight Loss Common Sense Warnings and Disclaimers before commencing a reduced calorie diet.
Picture credit: © 2013 iStockPhoto LLP
Konstantin Monastyrsky holds a degree in pharmacy. He is also an expert in forensic nutrition and has written four books about health and nutrition, including the acclaimed Fiber Menace. He’s twice been featured speaker at the international Wise Traditions Conference.