Diet logic

I just finished reading Amp's case against diets at Alas, a Blog.*  Ezra and Jane Galt have also posted reactions to Amp's post.

If diets don't work, why do people keep using them? We often hear that people want "quick fixes" instead of lifestyle transformations. That doesn't really explain the popularity of diets. Most diets make the dieter feel miserable. In fact, I've been driven to writing this post because of the incessant chatter of my dieting cube mates. They can scarcely talk about anything else. They can't think straight. They are irritable. They are spending huge amounts of money on books and prepackaged meals. Most of them aren't even losing weight.

My coworkers don't really "need" to lose that much weight, even by their own standards. In theory, if they could just end every day 70 calories in the red, they'd all be at their goal weights by bikini/Speedo season. So, why aren't these people more attracted to slower, more gradual weight-loss regimens?

I submit the answer is epistemological rather than physiological. People go on diets because don't have reliable, detailed information about their own energy balance on a day-to-day basis. We've all read that an extra apple per day could translate into a 10-pound weight gain in a year. By the same token, switching from sugar to sweetener in your coffee would be expected to produce a 10-lb weight loss in the same period.

In theory, weight loss should be simple. Figure out how many calories you need to maintain your weight. Then eat just a little less, or exercise just a little more. We shouldn't need structured diets in order to lose weight. Portion control should work just fine.

The problem is that we can't really tell how many calories we need, or whether some minor lifestyle modification is slowly depleting fat reserves. Of course, there's always the fear the body's metabolism is slowing down to compensate for the missed calories. I think the real appeal of diets is that they provide outside assurance that a change in eating will produce visible results in a short period of time. The need for speed isn't just impatience, it's a desire for concrete evidence that a particular program is working.

We all know people who have been fighting the same 10lbs for years. They go on some diet, make themselves (and everyone around them) miserable for a couple of weeks, lose the weight (or not), gain it back (and more), and grimly resume the cycle. These people are often rational and highly self-disciplined. So, why do they prefer to go on uncomfortable and unreliable diets instead of simply tweaking their lifestyles.

I have a question for my physiologically-minded readers out there. Would it be possible to develop a highly sensitive home-test for energy balance? Scales don't work very well because they aren't that accurate and other factors like fluid retention tend to obscure the tiny incremental declines that lifestyle changes are supposed to produce. Also, scales don't measure body composition, which is a much more important variable than weight, per se.

Would it be possible to create a breathalyzer or a urine test that monitored metabolites associated with fat deposition or fat oxidation? (I know the Atkins people are crazy about their ketosis sticks, but those just measure whether fat is beign burned, not whether the body's fat stores are actually being depleted. On a high fat diet like Atkins, much of the ketosis could be from dietary fat rather than fat loss.)

If someone developed a home test that measured net fat storage or net fat burning, the diet industry would collapse. People would just be able to balance their energy budgets the same way they balanced their checkbooks.

*At this point, the evidence is overwhelming that weight-loss diets are a poor treatment for obesity. By "diets," Amp means structured time-limited eating regimens. Going on a diet is not the same thing as changing one's diet, i.e., improving one's eating habits. In his post, Amp also argues that most obese people won't lose a lot of weight by eating healthier. Nobody disputes the health benefits of a balanced nutrient-rich diet. Good eating habits benefit everyone, including obese people. The only question is whether a significant percentage of people who are significantly overweight and eating badly can solve their weight problem by improving their nutrition.

Comments

[rob helpy-chalk]

People would just be able to balance their energy budgets the same way they balanced their checkbooks.

But a lot of people can't manage their checkbooks, and have to resort to a similar array of self-help books and get rich quick schemes to deal with finances.

We have the kind of knowledge of our finances that you wish to have of personal energy. With a little disciple (ok, a lot) we can know where every dollar comes from and where every dollar goes.

Yet people (lots of them) need debt counciling, self help books, and often resort to get rich quick schemes.

Therefore the problem is not epistemological.

[Alon Levy]

The only question is whether a significant percentage of people who are significantly overweight and eating badly can solve their weight problem by improving their nutrition.

Well, can't you do an analysis of the difference between the US today and the US 30 years ago, or the US and France today, to determine that? I presume that if increases in the population's average weight correlate with diets with more calories, then improving their eating habit will help a significant number of overweight people reduce their weight.

[Lindsay Beyerstein]

Weight control is compounded by ignorance in a way that finances are not. Imagine trying to balance your checkbook if you only knew your income and expenditures to within plus or minus 15% (and that's the equivalent of being very diligent with regard to energy balance. It's pretty easy to estimate energy intake, but it's much harder to know what your exact caloric needs are). Add to that the fact that your apparent balance would fluctuate over course of the month because of non-financial factors.

Imagine if saving was like those minor lifestyle modifications. You'd just toss a few bucks into the black box every day. Some or all of the money might be falling through the cracks. Or it might be siphoned off for other projects without you knowing. You have no way of knowing how much of that money was ending up in your account. Personally, I'd find it even more difficult to save small ammounts on a regular basis if I couldn't check to make sure that all of the money was being credited to me.

To me, financial planners and nutritionists have similar jobs. They're supposed to teach people reliable guidelines for managing their finances on a regular basis. Obviously, even with the best advice, many of us will fall short because of akrasia, or unforseen circumsntaces, or whatever.

Diet book hucksters are in a similar category to get-rich-quick schemers. There's always going to be a baseline level of guillibility in the population.

I'm arguing that fad diets attract a segment of the population who wouldn't go for them if they could simply monitor their energy intake and expenditure with enough precision to assure themselves that their efforts are actually working.

[Njorl]

I think Lindsay's on to something. Some kind of calorimeter-suit would be ideal. A skin-tight unitard would be just the perfect form for it - preferably a shiney one. The wisdom is born out by how often you see them in futuristic TV shows and movies. Now we know why! The soles could have scales. The stretching material could accurately measure body volume. Heat transfer and perspiration could be monitored! The wrist-computer could accurately relay proper dietary regimen. Plus, if you're always wearing a shiney, skin-tight unitard, you're damn well gonna make every effort to stay in shape.

[rob helpy-chalk]

A skin-tight unitard would be just the perfect form for it - preferably a shiney one. The wisdom is born out by how often you see them in futuristic TV shows and movies.

My theory is that we could actually force technological development simply by making shiney, skin-tight unitards fashionable. If enough people wore silver lamé jumpsuits, the flying cars would just show up.

[Alon Levy]

The most accurate way to measure your body volume is in a bath, preferably one where the horizontal cross-section has constant area.

[michael Schmidt]

>Would it be possible to develop a highly sensitive home-test for energy balance?

We may already be equipped with such a test: hunger. I lost weight when I decided that I needed to feel hungry for a good part of the day, and that I shouldn't respond to mild hunger by eating.

[Mandos]

Doesn't work for everyone. I feel hungry constantly, I think.

[michael Schmidt]

Does your hunger vary by degrees, or is it constant?

[Njorl]

The problem is, our hunger responses were honed by evolution. Every calorie was a good calorie. You had very few Homo Erectus guys with congestive heart failure and morbid obesity. Many of the foods we eat throw our hunger response all out of whack. They are not designed to handle bread, let alone twinkies.

One of the more powerful aspects of Adkins is the way it reduces hunger. A lot of the carbohydrates we eat will cause an unwarranted hunger response shortly after being consumed. My own pet theory (no idea if it is worth a damn) is that this is our body's way of telling us "This is a valuable food to eat. Eat as much as you can now before something else gets it!" That was useful for Australo Pithecus. Not as useful for Njorlus Rotundus.

[Alan Bostick]

People go on diets not because they don't have reliable, detailed information about their own energy balance on a day-to-day basis; but because we are taught over and over again through many channels of experience over the course of our lives to hate our bodies for being fat.

I predict that if such a test as you describe, Lindsay, were to become available, Jenny Craig would simply add it to her product line and sell it to her victims at a substantial markup.

[Lindsay Beyerstein]

I just wish that my hungry coworkers were as stoic and cheerful as Mike.

As I see it, the problem is that they only believe that they are losing weight if the feel hungry all the time. In theory, it should be possible to lose weight more slowly without feeling hungry at all, i.e., by simply substituting sweetener for sugar and walking two extra blocks every day.

My associates don't trust the small changes to get them to their goal in time for bikini season, so they decide to do something drastic and short-term. Of course, they get too hungry, overeat, and end up worse off than they started.

It seems that their main problem is that people don't have a reliable way of tracking the benefits of small, healthy changes over time.

[maurinsky]

I'm overweight, and I have successfully lost weight on the Weight Watchers program. What is *really* difficult about losing weight is changing your habits. I followed WW pretty devoutly for 4 months, after school ended, and lost about 30 lbs. And then the fall semester started, and I was running from work to home to drive the kids around to my own classes, and I gradually put it back on, because once I was back into the day to day chaos of life, I reverted back to my old habits.

[Brad Howard]

This is post has quite a few interesting twists. The correlation between "get rich quick" and "get slim quick" is dead on.

The diet and fitness industry preys on hope. In actuality, one could make an argument that the success of the health and fitness industry is directly related to the failure of it's customers.

Everyone knows that someone that is pretty emotional about losing weight is much more prone to making illogical decisions based on weight loss. The "lure" of the quick fix, however far it pushes the boundaries of ethics, is one of the most proven marketing tactics around.

Remember also that we live in a society that tosses away the responsibility of self. It's always someone else's fault that a person is overweight (or maybe they have diabetes, a thyoid condition, etc, etc). In my experience, very rarely does a person have a condition that was not brought on by themselves.

Even if a method for calculating the exact energy expendatures of a person manifested, the question remains: Would any "desperate" person use it? In my humble opinion, the mentality of society has more to do with the state of obesity than any food pyramid or fast food chain.

[Mandos]

Does your hunger vary by degrees, or is it constant?

If I stuff myself, I'm no longer hungry. Otherwise, I'm basically just hungry, unless I'm sick. At least that's how I've been feeling this week.

[michael Schmidt]

I agree, Njorl, that our hunger responses were honed for different living conditions. Under these living conditions, we were hungry most of the time, so that we would spend most of our time searching for, hunting, and growing food. So we need to reinterpret hunger not as a signal to eat, but as a signal write more proposals, sell more widgets, build more houses, or grade more papers....

[michael Schmidt]

In theory, it should be possible to lose weight more slowly without feeling hungry at all, i.e., by simply substituting sweetener for sugar and walking two extra blocks every day.

Actually, I don't think that's empirically true. What got me to start losing weight by being hungry more was an article in Science years ago that said, in effect, if you start losing weight, your body will signal that by increased hunger, even if you're still overweight.

[donna]

Yup. The body maintains a certain set point, and if it goes up or down, you'll feel more or less hungry. A lot of people become overweight because this little "thermostat" doesn't work right.

A bit of weight up or down isn't the issue. The issue is maintaining a healthy lifestyle and eating the right combination of foods *for you* to stay healthy. Some people are healthier being thin, others are actually healthier being a little overweight. Some are too thin to be healthy, and some are too heavy. And we are all different, and have to find what works for us. I think the popularity of diets is their contribution to that search for what makes us feel good and healthy. But, the American diet in general isn't very conducive to good health. People get too much sugar, too many carbs, too much whatever without realizing it and end up feeling miserable. We have the Starbucks addicts downing their triple lattes, the fast food garbage everywhere, etc, etc. Where are the healthy fast food places? Few and far between.

And the whole American system, from work to school to lifestyle, is designed to stress us out and make us feel like crap. And stress leads to weight gain, and the whole cycle continues....

[michael Schmidt]

The body maintains a certain set point, and if it goes up or down, you'll feel more or less hungry. A lot of people become overweight because this little "thermostat" doesn't work right.

I seem to recall the "set point" is actually adjustable--but only upwards, not downwards. You may be "set" at 150 lbs., then have a period of excess eating and/or low activity, and gain ten pounds. Now you're "set" at 160. If you drop back to 150, you'll be hungrier than you were at 150 before. 160 is your new set point. It sucks.

[Mandos]

160 is your new set point. It sucks.

This doesn't change even over a long time?

[jrochest]

The problem with the long term thing is that you have to accept being just slightly hungry, and never really full, as a constant state of being. Which is rather like accepting being just a little bit too cold, and never really warm. It's not easy -- most people eventually eat what their bodies tell them to, and most bodies opt for comfort.

[gmanedit]

A lot of people think they're hungry when they're not; they don't know how hungry feels. I once went on a three-day fast (actually, two and two thirds days—friends came over and we went out for dinner) and learned that I wouldn't die if I missed a meal. What works for me is eating slowly—I'm the last to leave the table—and stopping when I'm no longer hungry; after that, eating feels like work. Of course, what you eat has to be good: no (or minimal) processed food, nothing with hydrogenated fat or corn syrup. Also good: a compelling hobby and (for the night eaters) going to bed early.

[Mandos]

Is the body optimizing for a certain amount of fat, or just a certain amount of size, though? For instance, would muscle-building alter the balance?

[Helen of Troy]

Mandos,
Once concept you might be interested in is the "volumetric" diet concept. You can add it as a feature to any diet or weight loss plan.

Its the idea that people should eat foods with lots of volume per calorie. As long as those foods can make you feel full, you'll feel full faster on less calories. The food has to have some fat and protein to trigger fullness, so just water or just drinks won't work.

So, for example, a steak alone could have 800 calories, but not be large enough in size to make you feel full. For the same 800 calories you could have a big soup, a salad, a salmon steak and a berry dessert: those would fill you up.

By learning in general what types of foods are better and worse for volumetrics, you can make whatever diet plan you're on make you feel fuller. (Unless you're on the steak, pasta, cheese and butter diet.)

[Midnight Mike]

Philosophically, Lindsay, it appears that your argument is a restatement of Socrates' argument: if a person was fully cognizant that something was bad for them, that knowledge alone would be enough to cause a change. In other words, reason, alone is a sufficient motivator. In still other words, reason should be sufficient to overcome instinct.