Losing Weight     Computer Tools

Perfect Weight Forever

The superior man makes the difficulty to be overcome his first interest; success comes only later.

—Confucius, Analects, c. 500 B.C.

After you've attained your weight goal, it's only natural to worry about whether you'll be able to stay thin, especially if you've dieted before and later regained all the weight you lost. Friends who greet you with a cheery “Say, you've lost a lot of weight. Now, can you keep it off?” hardly contribute to your peace of mind.

In fact, there is no reason for anxiety about gaining back the weight you've just lost. Most people regain weight after dieting for the very same reason they were overweight in the first place: their appetite doesn't tell them how much to eat. Unlike most dieters, you not only know the cause of the problem, you have a solution for it: a feedback system, an eat watch. What's more, since it's just allowed you to lose weight you have no reason to doubt its reliability. Now we'll see how the eat watch that guided your weight loss can guarantee you'll never need to diet again.

Regaining: the problem and the cause

The statistics are depressing. The vast majority of people who lose weight end up, in relatively short order, gaining back every pound they lost. Perhaps it's happened to you; it happened repeatedly to me. Seemingly, at the very moment of triumph, the seeds of its undoing are sown. After a few cycles of depressing, uncontrollable weight gain and painful dieting, it's tempting to just give up; to assume you were never meant to be thin. Well, right now you are thin, whether for the first time or the twentieth. How can you evade the fate of most dieters and avoid regaining the weight you've lost? By relying on the same feedback you used to lose weight.

Let's try to understand why so many people fail to keep weight off after struggling to lose it. The rubber bag tells us that weight gain stems from a very simple cause: eating more food than the body burns. Feedback explains why: people prone to overweight lack a built-in feedback system to balance the calories they eat against what they burn; their appetite doesn't tell them to stop eating when enough calories have gone in.

A person with a broken feedback system will always tend to gain or lose weight. In the Food and Feedback chapter we've seen how Oscar and Buster, victims of incorrect feedback, gain weight simply by heeding the deceptive message of appetite. When Oscar or Buster go on a diet, the diet tells them what to eat and when. And, for reasons we now understand, it works! As long as they follow the diet and don't cheat, they lose weight as rapidly as promised and arrive at the end of the diet thin, happy, and feeling in command of their weight.

Then they put the diet away and rely, once again, on their built-in feedback system to tell them how much to eat. But it's still broken! Sure enough, their weight starts to creep upward and before long all the progress of the diet is erased. People with a tendency to gain weight need continual guidance about how much to eat. Withdrawing this guidance at the end of a diet, or couching the need for ongoing feedback in a manner that implies, “You're a fatty, and to be slim you'll have to spend the rest of your life on a diet” is as deplorable as lending a pair of glasses to a nearsighted person for six weeks, then removing them and saying, “OK. You're on your own.”

If your eyes don't focus, you need optical correction to live a normal life, and you need it all life long. The fix that lets you see as well as a person born with perfect vision needn't be obtrusive nor prevent you from doing anything you wish, but you have to continue using it. If you happen, instead, to lack a built-in eat watch, you shouldn't feel any more guilty about technologically overcoming that limitation than your friends do about wearing glasses. Gotta problem? Quit whining, fix it, and get on with yer' life!

Causes for confidence

Consider how you, having achieved your weight goal from an understanding of the rubber bag, feedback, and how the trend reveals the true balance of calories, differ from a dieter ignorant of all these “gory details,” who, seeing his target weight appear on the scale assumes success is at hand and appetite back in command.

You're armed with data, charts, and direct personal experience that tell you precisely how your body works. You don't have to trust any book, especially this one. You've devised a diet plan of your own, seen for yourself how it worked, and used it to achieve a long term goal many people never attempt.

You've survived an unpleasant experience, shedding weight, and there's no motivation quite so strong as the desire to never endure that again.

You've learned, by riding out the most difficult days of your diet, the distinction between real hunger and simply wanting to eat. You understand how portions at meals must be controlled to match calorie needs, not by a sense of feeling “full” while still at the table.

You've stabilised your weight near the goal you set for yourself. Permanent weight control is now just a matter of preserving this stability.

You're beginning to think of yourself as thin and healthy; these attributes are becoming part of your sense of self. Before long you won't consider forfeiting them any more than you'd contemplate cutting off a finger.

Feedback forever

How can you guarantee you'll never regain the weight you lost? Suppose your weight goal is 150 pounds and your appetite feedback curve is the disastrous one shown above. If you rely on your appetite alone, every time you eat too little you'll get an unmistakable signal to eat more, but overeating raises no warning. Overeating actually tends to make you eat more, since once your weight begins to creep upward you'll get depressed and seek solace in food. When you end your diet at 150 pounds, you're treacherously balanced on the flat part of the curve there. As long as you stay close to 150 all will be well. You're like the backwards-wired thermostat which didn't cause a problem as long as the temperature stayed close to 70 degrees. Eating too little is no problem; smooth negative feedback tells you to eat more. But inevitably, sooner or later, you'll eat a little too much: over the holidays, at a party, or when you can't gauge portion sizes accurately. Then, as your weight begins to creep upward, the malign influence of positive feedback takes command, and weight gain begets additional overeating in a process that literally feeds upon itself.

The initial overeating that set off the destructive feedback loop was probably an isolated incident, not a permanent change in diet. It may even have been inadvertent, the result of additional calories added to a regular meal or reduced physical activity unaccompanied by lower calorie intake. The correction needed to restore balance is usually small and easy to make. But if the slow creep upward isn't spotted and arrested in time, before long you've gained 10 or 15 pounds and you're in a real mess. Losing that much weight requires a serious diet and the very thought of going back on a diet, particularly so soon after the last one, is hard to entertain. The temptation to abandon weight control is tremendous once things have gotten this far out of hand; you're well on your way to giving back all the gains of your diet.

The problem, clearly, is lack of feedback. You need continual guidance to achieve an accurate calorie balance week after week, month after month, year after year. And we know just how to do that! The very same trend calculation and charts that tracked the calorie deficit during your diet can now guarantee stable weight forever. All you need to do is adjust your meals not for a calorie deficit, but to balance the calories you eat with the calories you burn.

To control your weight you set limits to the fluctuation of the trend and plan specific actions whenever the trend line impinges on a limit. As when dieting you only consider the trend; daily weight is used solely to calculate it. The band is a 5 pound region centred around your goal weight; this encompasses the normal week to week variation. There's no need to be obsessed with a perfectly constant trend line; a couple of pounds more or less aren't really noticeable and in any case are swamped by day to day changes in weight. If your weight goal is 150 pounds, the band ranges from 147.5 to 152.5, shown as dashed lines on the chart. As long as the trend is within this range, there's no reason to change what you're eating. Eat whatever you like, consistent with the calorie burn rate you determined at the end of your diet.

Fine tuning

Continue logging weight daily and producing trend charts at the end of the month. As long as the trend remains within the five pound band around your goal, month-end chart analysis focuses on the slope of the trend line and the calorie excess or deficit it indicates. Consider the following trend chart.

The goal is 150 and the trend is allowed to vary freely in the 147.5 to 152.5 band. Since the trend never touched either limit this chart represents success in keeping the trend close to the goal. However, there's a slight upslope, equivalent to 72 extra calories a day. In addition the trend varied between 150 and 151, not back and forth around 150. This suggests you should cut back slightly on calories the next month. Since 72 calories a day is less than one tablespoon of salad dressing or about half an ounce of cheese, you could make the adjustment by lightening up slightly on salad at dinner or by ordering your lunchtime burger without cheese. Had the trend line remained below 150 all month and shown a slow downslope, you'd add comparable foods in the next month to move up to 150.

Adjusting your food consumption based on the trend forms an exquisitely sensitive negative feedback system. The slope of the trend reacts to even the slightest changes in calorie balance and allows you to make adjustments, up or down, so slight they are scarcely perceptible. By insuring you get just the calories you need, you're guaranteed to never be hungry as long as you adjust the size of your meals and their schedule based on your need for calories throughout the day. As you gain experience balancing the trend line it will become second nature, and you'll probably find the fluctuations decrease even more.

Early warning

Not only does the trend let you balance your calories, it's a tireless sentry that notifies you of emerging weight problems while they're still easy to correct. Suppose you just printed a trend chart like this one.

Clearly, a dramatic change in calorie balance occurred in the last three weeks of this month. This rapid climb, starting from the goal weight of 150 indicates an immediate need to reduce your calorie intake by about 350 calories a day (the 329 excess shown in the chart plus a tad more to cause a slow drift downward to 150 pounds). Since you were eating too many calories and gaining weight, cutting back to slightly fewer than what you're burning should not leave you hungry, as your daily deficit will still be less than 100 calories as you return to the goal.

Bumping the band

Decide for yourself how closely you want to track the slope of the trend and balance your calories. You can view it as a kind of game, worth playing well in pursuit of a perfectly flat trend line. On the other hand, the whole idea of adding ten calories one month and subtracting fifteen the next may seem a particularly horrid example of obsessive compulsive behaviour. No matter, what's really important is what you do when the trend line wanders outside the 5 pound band centred around your weight goal. If your goal is 150 pounds, the band limits are 147.5 and 152.5. Whenever the trend line ends a month outside this range, action to correct the divergence is triggered. In the chart above, the rapid rise left the trend right at 152.5 at month's end. If the rise were not halted by reducing calories based on the slope of the trend, by next month the trend would have climbed well above 152.5, requiring a mandatory cutback to restore the trend to below that mark.

If the trend changes during a month, the calorie excess or deficit reported in the chart may be misleading. When the trend reverses, it's best to calculate the calorie adjustment based on the start and end weights of the trend divided by the number of days the trend continued; see the instructions for manually calculating calorie excess or deficit. Excel users can obtain the calorie balance from a partial month trend by selecting the trend cells for the portion of the month containing the trend (for the chart above, you'd select August 8th through August 31st), then picking WEIGHT TREND SNAPSHOT or pressing the accelerator key CONTROL+t. A window like the following will appear.

By considering only the part of August when the trend was rising, we obtain a more accurate estimate of the rate of weight gain and calorie surplus. Instead of the 329 calories calculated from the entire month, during the last three weeks there was actually an excess of 465 calories per day, indicating the need for a more severe cutback in food. If you were calculating by hand, you'd subtract the trend value on August 8th, 149.6, from the trend at the end of the month, 152.5, divide by the number of days between those dates (31 − 8 = 23), then multiply by 3500 calories per pound, yielding:

(152.5 - 149.6) / (31 - 8) pounds/day  3500 calories/pound ~= 441 calories/day

This estimate is equivalent to that calculated by Excel for the purpose of planning a calorie cutback.

When the trend rises above the band, reduce your calorie intake by more than the excess reported by the trend chart or calculated from the most recent trend as explained above. Next month's chart will show a falling trend line which should soon return or already be within the 5 pound band. Once the trend line ends the month between 147.5 and 152.5, resume the usual minor adjustments to your food intake as described above, based on the slope of the trend.

The adjustment you make when the trend line wanders outside the band is up to you. After you have a year or so of experience controlling your weight, you can usually figure out the reason for the rise pretty easily (too many extra large buckets of popcorn at the movies, your discovery that Señor Picante's Macho Cheese tortilla chips are the perfect complement to your Saturday night poker game, etc.). Correction consists simply of cutting back on the food that's responsible for the extra calories, plus a little more to bring the trend down to within the band.

How you adjust your calorie intake isn't important. What is essential is that you do adjust it. Whenever you end any month outside the 5 pound band you must deliberately reduce calorie intake (if you're above) or increase calorie intake (if below), by more than the calorie excess or deficit reported in the last trend chart. Once you make the indicated adjustment to what you eat, the trend line will quickly return to the goal weight.

Hitting the wall

If you make minor monthly adjustments to your food intake based on the slope of the trend your weight will rarely stray outside the 5 pound band requiring mandatory adjustments to your calorie intake. But, over the years, stresses and circumstances unanticipated by carefully drawn plans will occur: a four month tour de France gastronomique, a coupla years in the slammer for insider trading, a sudden obsession with cheesecake, a bout of malaria. Events like these may set you heading for a serious weight problem. But long before things spiral out of control, the trend line will detect the danger and invoke stronger measures to avert catastrophe.

The five pound band around the goal weight, shown here in grey, contains most normal fluctuations. A ten pound region limits the permissible variation. The brick wall indicates the region the trend is prohibited from entering. With a goal weight of 150 pounds, brick walls are built at 145 and 155. (Only the upper brick wall is shown on this graph, as it's the one most of us worry about.) If the trend at the end of a month exceeds 155 pounds, the warning bell sounds and immediate action is taken to return the trend to the goal. What immediate action? Simply resuming the very same meal plan you used to lose weight in the first place. You know it works; you adjusted it over the duration of your diet into something you can live with. Dust it off and use it now.

With a 10 pound brick walls around your goal weight, even if you hit the wall above your goal, you only need to take off 5 pounds. With a 500 calorie a day deficit you can do that in little more than a month so you're hardly looking at a severe calorie cutback nor a long-term diet to restore stability. In the unlikely event of the trend ending a month more than five pounds below the goal, add about 500 calories a day to your diet to bring it back.

In the chart above, the trend ended the previous month above 155, indicating the brick wall had been hit. The meal plan, calculated for a 500 calorie a day deficit, was put into effect immediately. The trend continued to rise for the first week of the month since daily weight remained above the trend line, but before long the diet took hold and the trend began to fall at the expected rate of about a pound a week. By month's end, the trend had fallen to within the 5 pound band around the goal. After hitting a brick wall, it's best to continue the meal plan until the trend goes past the goal weight since going off the diet may cause the trend to bounce upward, but you could end the diet at the conclusion of this month and return to managing the trend within the 5 pound band around 150.

If you adjust your calorie intake month by month, variations outside the 5 pound band will be infrequent. Since you make adjustments when the 5 pound band is violated, hitting the brick wall will be exceedingly rare. Still, it can happen, and if and when it does you are ready. If the first and second layers of defence against gaining weight fail, a sure-fire solution, resuming the diet that got you to the goal in the first place, is invoked and will correct the problem, whatever its cause, in little more than a month. If you do hit the wall, try to understand why. Hitting the wall indicates the normal weight regulating feedback failed, and once you figure out why you can avoid the discomfort of dieting in the future.

But even if you hit the wall and have to diet, it's not for long, and the incipient weight gain is corrected well before your clothes don't fit or anybody notices you've gained a pound. Hitting the wall and dieting back to the goal is a private matter between you and the trend line, and you are the sole beneficiary. The best way to think of the brick wall is like a parachute. You hope you'll never need it, but it's nice to know it's there.

Feedback on the job

What we've constructed, by defining a 5 pound band for variation and a 10 pound range surrounded by brick walls, then prescribing the action to be taken when the trend is in each region, is a negative feedback system to replace the built-in one that misleads us into gaining weight.

By using the trend to adjust food intake, we have implemented a very different feedback system. As weight varies within the 5 pound band around the goal, 150 pounds here, it is subject to only a minor degree of feedback, applied by monthly adjustments to what you eat based on the slope of the trend line. If you choose not to bother with such small adjustments, the floor of the feedback curve from 147.5 to 152.5 pounds will be flat and your weight completely free to vary within that band.

Once the trend ends a month outside the 5 pound band but within the brick walls, calorie consumption is adjusted. The size of the adjustment is determined from the calorie excess or deficit indicated by the trend. Thus, when the trend strays outside the band it encounters negative feedback proportional to the calorie imbalance that caused it to diverge. This feedback, shown as a steeper line outside the 5 pound band, should normally return the trend to within the band in short order.

If, for whatever reason, the feedback invoked when the band is crossed doesn't have the intended effect, the trend will sooner or later hit the brick wall. When this happens, bang-bang negative feedback is triggered to ensure the trend is quickly reversed and brought back to the goal. Resuming a meal plan already proven effective for losing weight (or adding comparable calories if the trend hits the brick wall below the weight goal), provides absolute assurance the trend cannot slip out of control. This constitutes very strong negative feedback that kicks in when the brick wall is hit, shown by the steep rise in the feedback curve at that threshold.

The rules of the game

The adjustments to what you eat based on the trend's relationship to the goal weight are as follows.

More than 5 pounds above goal.  You've hit the high brick wall. Immediately resume the meal plan you used to lose weight and stay on it until the trend falls to less than the goal weight.

Between 2.5 and 5 pounds above goal.  The trend has risen above the band. Reduce your calorie consumption by cutting out food slightly more than the calorie excess reported on recent trend charts.

Within 2.5 pounds of the goal.  No adjustment is required. You can, if you wish, fine tune the trend by adding or subtracting food equal to the deficit or excess reported in the last month's trend chart.

Between 2.5 and 5 pounds below goal.  The trend has fallen below the band. Increase your calorie consumption by slightly more than the deficit reported on recent trend charts.

More than 5 pounds below goal.  You've hit the low brick wall. Start with the meal plan you used to achieve stable weight at the end of your diet, then add an additional 250 to 500 calories per day. If, at the end of the next month, you're still more than 5 pounds below the goal, add even more calories to your meal plan.

How can it fail?

From everything we've learned about feedback, it should be abundantly clear that there is simply no way your weight can get out of control as long as you keep the feedback this plan provides in effect. And whatever could possess you to abandon it? A desire to be fat once again? Not bloody likely, especially after you've just spent so much time and trouble getting thin! Because it's too much bother? Preposterous! It only takes 30 seconds a day to log your weight, compute the trend, and plot it on a chart, even if you do it by hand. To avoid restrictions on what you eat? But there are no restrictions, not a single one. All that feedback, the eat watch, does is tell you how much to eat—you eat whatever foods you like, whenever you wish. What you choose to eat can make a difference in how you feel, but it won't affect your weight.

Will you tire of making the continual adjustments? Don't confuse the incremental month to month changes in what you eat based on the trend with the rollercoaster of binge eating and dieting that afflicts so many people. First, as long as your weight never strays outside the 5 pound band, adjustments are completely optional and in any case are tiny: fewer calories per day than a glass of skim milk. As you monitor the trend month after month, you'll probably find that before long you don't have to do any arithmetic or formal meal planning at all. Whenever the trend's a little above the goal, eat less, and when it's below the goal, enjoy a little more every day. It is entirely possible to spend years without ever straying outside the 5 pound band.

Will you become frustrated by repeatedly having to cut back calories when you exceed the band or hit the brick wall? Again, no. As you master controlling what you eat, these occurrences will become increasingly rare, but even when it happens it's not that awful. Since the brick wall triggers weight loss when the trend exceeds the goal by 5 pounds, you're never more than about a month from the goal. In fact, if the diet you use after hitting the wall has a moderate 500 calorie a day shortfall, within three weeks the trend should be back within the band.

The only way you can gain back the weight you lost is by deliberately choosing to; by discarding the simple and easy feedback that keeps your weight under control; by taking off the eat watch. The slow creep into snowballing weight gain that is the undoing of most dieters simply cannot happen to you any other way. And if you aren't already committed to maintaining your weight, wait until you've gotten really used to being thin and fit. Then no temptation will induce you to resume the life of a fat person.

Proportional feedbag

The only ongoing irritation in managing your weight is planning meals and calculating calorie intake. As you gain experience in keeping your weight within the band and confidence in your ability to do so, you will eventually be able to extirpate this lingering annoyance from your life.

The actual number of calories you eat and burn every day, while interesting to know, doesn't really matter. Only the balance between calories in and calories out, expressed by the difference of these quantities, affects the rubber bag. That's why the block in the diagram of the eat watch that controls the Eat! signal subtracts calories burned from calories eaten. To keep your weight within the band, all you have to do is keep calories in balance: the result of the subtraction at zero.

After several months of planning meals and adjusting calorie content up and down to stabilise the trend, you may find you're developing an excellent sense of how many calories different foods contain and, more importantly, how much and what kinds of food are appropriate at each meal. You're still planning meals but you're doing it subconsciously, all in your head. In effect, you've advanced from planning meals by counting on your fingers, adding up tables of calories and carefully measuring food, to doing sums in your head. No longer will you look at a bowl of mashed potatoes and think “137 calories a cup.” Instead, you know that a dollop the size of a baseball with gravy on the top is about right along with a drumstick of broiled chicken and an ear of corn on the cob. Through carefully planning meals, you've taught yourself by practice and repetition, the only way humans ever learn anything, how to gauge the proper amount of food at each meal.

You're not relying on your appetite; it's still broken, in all likelihood, and shouldn't be trusted in any case. You're using your eyes to measure what your stomach can't: how much to eat at a sitting. After a year of stable weight, you will probably have become sufficiently accomplished at this skill so the only time you resort to a calorie table is upon encountering new food items, to find something comparable among the foods you regularly eat. As you practice the skill of planning meals by eyeball, the trend provides constant guidance. Any tendency to err in either direction quickly manifests itself in a rising or falling trend, which not only tells you there's a problem but how many calories you're high or low. Further, the band and the brick wall protect you during the transition from formal meal plans to your own judgement. If you try to dispense with meal plans too early, the trend will let you know by exceeding the band or hitting the brick wall, and the planning and adjustment required under those circumstances will rescue you before a real problem develops.

In a year or so, controlling your weight like this will seem as easy as riding a bicycle, and something you're no more likely to ever forget. Like riding a bicycle, it was far from easy to learn, but hard-won skills tend to be the most enduring. Unlike a bicycle, no matter how skilled you become in managing your weight, you need never remove the training wheels. Every day you continue to log your weight, every month you compute and chart the trend and make any necessary adjustments, and every year you add another dozen charts of stable weight to your ever-growing archive. When people ask “How do you manage to stay so thin?” you can answer honestly, “Simple, whenever I start to gain, I eat a little less. Whenever I start to lose, I eat a little more.” Simple, indeed. But, as we've learned from our long and arduous journey through the wilds of engineering and the swamps of management, from pounds of fat and thermostats, and rubber bags and things, simple does not mean easy.

Evading evangelism

Once you've succeeded in controlling your weight, a tremendous weight is lifted from your mind as well as your body. Discovering you have the power to lick a long-standing and difficult problem may motivate you to attempt many other things you scarcely contemplated before. Go to it! You gain not only physical stamina by losing weight, but a sense of power that contributes to anything you undertake.

But don't let success in weight control engender disdain and contempt for others who haven't yet achieved your happy state. Disrespect for and discrimination against those who happen to be overweight is bad enough already without adding recruits to the ranks of the self-righteously slim. You succeeded by understanding you suffered not from a character flaw or weakness of will, but a broken feedback system: not a deep-seated psychological problem but a built-in eat watch that ran too fast.

Now that your weight problem is solved, don't become a tiresome nag, exhorting others to emulate you. Your very success is the strongest form of persuasion: the argument by example. As the months pass and those who predicted, “Just wait, he'll gain it all back” are proven wrong, others may begin to wonder if they, too, can solve their weight problems as you have.

If you want to recommend this book, hey, go right ahead. But just because this plan worked for you doesn't mean it will work for everybody. Anybody can control their weight: it's simply a matter of balancing calories, but the means that work for you may seem intolerable or utterly baffling to the next fellow. That individual may eventually become thin and healthy with a plan that strikes you as fascism cloaked in mumbo jumbo. In this book I've tried to present a relentlessly rational approach to weight control. You can't persuade somebody to be rational. You're better off trying to out-stubborn a cat.

The dream

Oh my God! M-535: Advanced Topics In Differential Geometry, final exam 8:00 May 25: next Monday. I signed up for that course…but I never went to class—never even bought the textbook. I totally forgot about it. It's too late to drop the course now. And if I fail, I won't graduate and my job offer will fall through and….

Toss, turn: you wake up in a cold sweat and realise it was only a dream. Somehow, years ago, you did graduate, and this recurring nightmare is only a product of your mind recycling the anxieties of college days. This is “The Dream,” and almost everybody who survived college has it occasionally, even after decades.

The nightmare is so common it's been studied by psychologists. The funny thing is, it only seems to afflict people who eventually succeeded. Those who failed or dropped out don't have the dream.

Perhaps, a year or so after you've reached your weight goal and gotten used to thinking of yourself as thin and fit, you'll have a different dream.

Oh my God! I have just eaten an entire dozen jelly doughnuts. Mute but damning evidence is before me: the empty box, covered with my fingerprints already dusted by powdered sugar. I can't guess how many thousand calories it was and I lack the courage to look it up, but the scale will doubtless tell the tale….

Toss, turn: you wake up, dismayed and depressed, and in a few seconds, as consciousness seeps into your skull, you realise. It was only, like the years you spent overweight now increasingly seem, a bad dream.

Losing Weight     Computer Tools