Category: Diet

Here’s a handy online tool for calculating your exact BMI or Body Mass Index. This is the standard figure used for reckoning overweight and obesity.

The system is open to some criticism in that it doesn’t take into account all the relevant factors (e.g., is the person a body builder who has extra muscle in his weight, or a person who has suffered muscle wasting and has less muscle than normal inhis weight, or a person who is large or small boned), but it’s still nice to be able to calculate your exact BMI and see how you stack up against the idealized numbers in common use.

Another reader writes:

I always wondered why then peoples like the Italian or French tend to be a lot slimmer than Americans though their diet is definitely a lot higher on Carbs that most of the studies you are using recommend.

What is your take on this?

There are a number of factors that are potentially relevant here, but the big one is this: The traditional European diet–like the traditional American diet–is not as high in carbs (and particularly in refined carbs) as the one Americans now eat. People over there might be eating pasta, but in much, MUCH smaller portions.

But things are changing in Europe. Fast. The high-carb, high-sugar diet that Americans eat is now sweeping Europe, particularly among the young. The European overweight and obesity rates are spiking, and it has European health authorities very worried. They’re rapidly catching up to us.

A hundred years ago there wasn’t this difference, but America modernized its diet in the mid 20th century in order to maximize profits of the food industry, and Europe simply lagged behind doing so by a few decades. Now their diet is changing in the same way due to the same pressures (i.e., financial ones), and Europeans are starting to lose the battle of the bulge.

Here’s an article that explains it well.

Regarding my notes on the Kekwick diet research, a reader writes:

Very interesting results. However, if you take the same proportions of macro-nutrients in what you are currently eating, and reduce them all by the same amount (reducing calories, keeping same % of macro-nutrients), then you will loose weight acording to the usuall 3500Kcals = 1lbs formula.

I also wonder if there has been research where there was not such a huge differential (90%) to try to determine at what % the carb-insulin fat-increase effect takes place.

It is true that if you reduce calories far enough–regardless of the ratio of the macronutrients–that you will lose weight. The problem is what happens to your body as you do that. As the Kekwick research and other research has shown, a high-carb ratio has the effect of inhibiting weight loss in the calorie range where most people are comfortable. In other words, in order to consistently lose weight with a high-carb diet, many people have to reduce their calorie intake so far that the diet becomes torture for them to stay on, and they drop off it without making substantial progress toward their weight goals.

(Incidentally, the 3550 calories = 1 pound formula is an average based on the metabolism Americans tend to be in. For individuals, the actual amount will vary considerably.)

There has been research done on where the threshold is for weight gain, and the answer is interesting. First, there are two thresholds, one above which a person will gain weight (i.e., eat X number of carbs per day or more and your body will start storing new fat) and one below which one will lose weight (i.e., eat Y number of carbs per day or less and you will start burning fat).

Where these two thresholds are varies considerably from one individual to another. Some people are much more prone to weight gain or resistant to weight loss than others.

The thresholds also vary depending on the metabolic state that the individual is in at the time. This varies based on a variety of factors, including exercise and total caloric intake. For example, if you were to eat 10,000 calories per day, you’d probably gain weight even if none of them were from carbs, and if you ate 500 calories per day, you’d certainly lose weight even though all of them were from carbs.

FWIW, Atkins encourages people to find where their own thresholds are in the zone where they are comfortable eating (i.e., where they don’t feel like they are starving or gorging themselves). For most people, the number of carbs they can eat in this zone and still lose weight is rather low, but as one makes progress toward one’s weight goal the amount goes up until, when one arrives at one’s goal, one eats enough carbs to maintain one’s weight without losing further and without gaining weight back.

If you’d like the details of the approach, check out the book.

I did after my doctor recommended a few years ago that I go on the Atkins diet (which was much harder then than it is now, what with all the new low-carb products on the market). I lost seventy pounds before hitting a plateau (which I now think was due to slipping out of good diet habits), but I kept the weight off. Late late year I took a few months off from the low-carb approach to let my metabolism re-set, then went back on in mid-January. Since that time, I’ve lost over 40 pounds, an average of two pounds a week, without being hungry and feeling better than I had in years before discovering the diet.

Incidentally, the picture of me that you see on the blog is me before going back on the diet. I need to get a new one made, because I’m now quite a bit thinner than I am in that one.

‘Member how I said in a prior post that “The form of the calories don’t matter that much in and of themselves. A thousand calories of protein or fat or carbohydrates is still a thousand calories”? In saying that I was conceding an element of truth to a common dieting axiom: “a calorie is a calorie is a calorie.” This axiom is often used by those who tout calorie restriction as the key to successful fat loss. These folks would say that it doesn’t matter whether the calories you take in are in the form of fat, carbohydrates, or protein. All that counts for losing weight is losing calories.

But while it’s true (by definition) that one calorie represents as much energy as another calorie, that is much more to the story than this. As I went on to point out,

the type of calories does have an effect on the body’s metabolism because the body has to do different things in order to burn different macro-nutrients (i.e., protein, fat, and carbohydrates). If you change the ratio of the macro-nutrients you are eating, your body’s metabolism changes in order to digest and/or store them.

I’d like to document that now by citing a classic study published in 1956 by Alan Kekwick and Gaston Pawan (“Calorie Intake in Relation to Body Weight Changes in the Obese,” Lancet, July 28, 1956, 155-161). These researchers divided their test subjects into three groups, each of which ate a thousand calories a day that were principally composed of one of the three macronutrients. One group got a thousand calories a day that were 90% carbohydrate calories, another got a thousand calories a day that were 90% protein calories, and the third group got a thousand calories a day that were 90% fat calories. If the “a calorie is a calorie” maxim applied to weight loss, these groups should have lost the same amount of weight–or at least approximately the same amount of weight.

They didn’t.

The 90% protein group lost an average of .6 pounds per day of the study. The 90% fat group lost .9 pounds per day. And the 90% carbohydrate group actually gained .24 pounds per day.

What explains this?

The basic explanation is that your metabolism adjusts to the input you give it. If you put in primarily fat, it triggers one set of responses as your body gears up to utilize the fat and manage its energy output. If you put in carbs, it triggers a different set of respones. And if you put in protein, it triggers a third set. These have an impact on how much weight a person will lose. As the 1956 Kekwick study showed (and as subsequent studies have reinforced), if you give your body fat in the absence of carbohydrates then your body will go into fat burning mode. If you give it protein in the absence of carbohydrates then it will do the same, though the rate of fat burning will be less efficient.

On the other hand, if you give it primarily carbohydrates then it will slam on the brakes for fat burning and start hoarding the fat it has, even slowing your metabolism so that it can generate excess calories to try to hoard more nutrients since the sudden absence of fat from your diet has convinced your body that some kind of famine is going on and you need to go into emergency survival mode.

Subsequent studies have confirmed and amplified the Kekwick and Pawan results, and I’ll try to document some of those in future entries, but the basics were right there in the 1956 study.

This is definitely going into my regularly-read blog list.

This is definitely going into my regularly-read blog list.

A reader writes:

One thing I remember seeing in the news is that children in the US are much more overweight than in past generations.

Actually, the problem is much worse than children. The whole US population is much more overweight than in past generations. According to current statistics, two thirds of the American population is overweight (having a Body Mass Index [BMI] of 25 or more) and one third of the population is obese (having a BMI of 30 or more). This means that only a third of the population has a healthy weight by BMI reckoning [Source]. Now, there are some problems with the BMI scale (it doesn’t take into account muscular people or people who have suffered muscle loss), but it provides enough of a benchmark to show that there is a huge problem. Further, the problem is getting worse, and the trend toward obesity has been dramatically accellerating in recent years.

If your explanation of weight gain is true, and it may very well be, how does one also explain the much greater incidence of obesity among children (as well as adults) than in past generations? If the problem of obesity is primary biological, why would we see such a large increase in the percentage of obesity in today’s generations?

Actually, I haven’t thus far commented on why people gain weight. I’ve merely pointed out that the body tries to maintain a particular weight level homeostatically, which is why people find significant weight loss so difficult: Your body fights you as you start trying to lose. Under most diet strategies, the body will simply up your hunger level and give you cravings to get you to make up the calories that you are trying to avoid by following your diet program. How a person got to being overweight is a different question.

As far as why our generation is so much more overweight than prior ones, there are three basic reasons:

• The first reason is that we exercise less than former generations did. A hundred years ago, most people worked outdoors, which meant much more physical activity than we office-dwellers get today.
• The second reason is that we take in more calories per day than prior generations
• The third reason has to do with your question concerning the nature of the food we eat:

Perhaps it is not only a function of how many calories one eats, but also what kinds of calories one eats. Does a person gain more weight from eating 500 calories worth of donuts than they would from eating 500 calories worth of fruit, for example?

The form of the calories don’t matter that much in and of themselves. A thousand calories of protein or fat or carbohydrates is still a thousand calories. But the type of calories does have an effect on the body’s metabolism because the body has to do different things in order to burn different macro-nutrients (i.e., protein, fat, and carbohydrates). If you change the ratio of the macro-nutrients you are eating, your body’s metabolism changes in order to digest and/or store them.

And that’s where part of the problem comes in: One of the macro-nutrients–carbohydrates–triggers an insulin response in the body that can send your blood sugar skyrocketing (which is why diabetics have to regulate their carbohydrate intake and often need to take insulin to help control their blood sugar). But blood sugar will quickly fall again, and when that happens your body starts to get weak (which is why people get sleepy in the hour after lunch), and your body triggers a new hunger response in order to get you to eat more and thus raise the blood sugar level back to where it was (which is why you get hungry an hour after eating carbyhodrate-rich Asian food). The result is that eating too many carbohydrates puts you on a blood sugar roller-coaster that keeps leaving you weak and hungry, and when you eat to get your blood sugar back up, you take in more calories.

Now, guess what the big change has been in the last hundred years in our diets? That’s right: We take in way more carbohydrates, particularly refined carbohydrates that will make your blood sugar go nuts. Wherever this high-calorie, high-carb, high-refined carb “Western diet” gets introduced in the world, the problems of overweight, diabetes, and heart disease quickly follow. It’s simply not what our species is meant to eat. We’re hunter-gatherers by nature, and hunter-gatherers have a diet rich in protein and fat but not carbs, and especially not refined carbs.

Now, why has the weight problem been accellerating in America? Here’s part of the reason:

I’m sure you recognize the famous “Food Pyramid” or, as I prefer to call it, the “PYRAMID OF EVIL.” Like everbody else, I assumed when the pyramid first came out that it represented the diet you were supposed to eat to be healthy, but back then I hadn’t studied diet and nutrition. After my weight situation forced me to do so, I came back, looked at the pyramid again, and was shocked. “Man! This is the Give-Your-Children-Diabetes Pyramid!” I exclaimed.

The recommendations it makes are absolutely insane. It’s way out of whack with what our species is designed to eat. Six to eleven servings of grain a day is completely crazy for a hunter-gatherer species. The additional two to four servings of fruit only makes the problem worse.

People have the idea that fruit is a healthy food that ought to be eaten in large quantities, but this falls apart when one applies a little common sense. Ask yourself: What is the one foodstuff that everybody (hi-carb dieters, lo-carb dieters, the Food Pyramid, everbody) agrees needs to be eaten in very limited quantities? Sugar. Now, what is it that makes up prefer to eat fruit over vegetables? Sugar. Fruit has lots of sugar in it. In fact, that’s the main difference between a fruit and a vegetable: What we call a fruit has more sugar than what we call a vegetable. Biologically, they tend to perform the same function (they both tend to be the seed-bearing parts of a plant). One simply tastes better to us because it has more sugar in it, and so we have a different word for it.

If you compare the amount of sugar and other carbohydrates in fruits to the amount in manmade confections, the differences are not that great. They can even stand your expectations on their head. A typical 8″ banana that you’d buy in a store has 31 grams of carbohydrates in it. By contrast, a Hostess powdered sugar donut has only 19 grams of carbs. There are some advantages of fruit over pastry, but not near as much as people have been led to believe. About the best that I can say for most fruits is that they are less unhealthy as a major component of your diet (though, as with anything, in limited quantities they’re fine).

Now, here’s something you probably didn’t know about the Food Pyramid: Know which government agency puts it out? You’d think that it would be one of the ones that monitors public health, like the Food and Drug Administration or the National Institutes of Health or even the Center for Disease Control, right? Wrong. It’s a creature of the United States Department of Agriculture–the body tasked with monitoring and (in practice) looking after the interests of the farm industry.

The Food Pyramid is a marketing ploy designed to get people to eat the foods that the farm industry wants them to eat.

Why does the farm industry want people to eat certain foods? Look at the ones at the base of the food pyramid and compare them to those at the top. Except for the “use sparingly” category, the foods at the top almost all (a) come from animals and (b) require refrigeration. The ones at the bottom almost all (a) come from plants and (b) don’t require refrigeration. The significance of those facts is that the ones at the bottom of the pyramid are all low-cost to manufacture (plants don’t require as much investment to raise as animals) and high-profit items (because the cost of the end product doesn’t have things like refrigeration coming out of its profit margin).

Getting people to eat low-cost, high-profit foods may serve the interests of agribusiness, but those aren’t the foods our species was designed to rely upon, and making them the principal components of our diet is bound to lead to problems–like overweight, diabetes, and heart disease.

A reader writes:

I agree that just because someone is overweight doesn’t necessarily mean they eat to much…however it does mean they don’t exercise

I’m sure that you probably don’t mean this to be taken as a technical statement, but . . . it’s . . . not . . . true. It comes across as a diss to people who are overweight. It sounds like a cavalier dismissal of their situation, including whatever efforts at exercise they may be making. It would be better to make the statement in a more qualified manner, for as it stands it is subject to a number of criticisms:

1) Exercise is not a binary phenomena. People don’t fall into two classes of “those who exercise” and “those who don’t exercise” with no further relevant distinctions. Physical activity is something that exists on a continuum, and merely falling into the “does exercise” category is not a guaranteed cure for the problem of overweight.

2) Even falling into the category of “does a lot of exercise” isn’t a guarantee of losing body fat. Look at professional football players. Those guys tend to get a lot of exercise, but they also tend to have a lot of body fat (because they consume more calories in order to simultaneously [a] keeping doing the exercise and [b] keep their bodies at the homeostatic weight points they want to remain at).

3) Depending on the metabolic state one is in, doing exercise can increase the appetite one has, as the body tries to stay at its homeostatic weight point and responds by increasing appetite as physical activity increases. If you just add some exercise without addressing dietary considerations, this is likely what will happen to you: You’ll just eat more. (Paradoxically, there are also states–which dieters can exploit–where the body decreases appetite as exercise increases. The point is simply that not everyone who exercises is going to lose weight.)

4) Even when one is in high weight loss mode, exercise is rarely if ever a sufficient condition for that weight loss. Exercise tends not to add that much to the calories we burn each day. Consider:

A 6’0″, 200 lb., 30 year old man is likely to have a Basal Metabolic Rate (BMR) of 2019 calories per day (BMR Calculator). This is the number of calories he needs just to lay in bed, without adding any physical activity. If you add his daily work duties to this (let’s say he does office work), you might get the number up to 2500 calories.

Let’s just stick with his BMR for the moment, though. How much physical activity would he need in order for exercise to equal what he needs to just keep the lights on and the machinery working? Well, he’d need to generate another 2019 of calorie burning through exercise. How much is that? It depends on the exercise he does, but let’s take a common one that is easily within the reach of almost all dieters: walking. If a person of his weight walks briskly for half an hour, he will burn approximately 220 calories. This means that in order for his exercise-based calories to equal his BMR-based calories, he would have to walk briskly for 4.6 hours a day. (NOTE: There are some quibbles to make with these numbers, but they don’t affect the scale of exercise required, so we can stick with these numbers for purposes of showing the principle.)

Very few people are able to make that kind of exercise investment, and so exercise rarely plays as big a role in calorie expenditure as BMR. The result is that diet rather than exercise tends to be the most important factor in weight loss. In order to effectively lose weight, dietary change is what is needed. Exercise is an important adjunct to this (otherwise I wouldn’t do five miles of aerobic power walking per day, plus weight training), but exercise by itself is not the solution to weight problems for most people. It’s not even the major factor. Diet is more important.

6) Exercise also is not a necessary condition for weight loss. A few years ago I was dealing with a significant weight problem and lost almost seventy pounds without doing any exercise, simply by making a dietary change.

Diet rather than exercise tends to be the dominant factor in weight loss. The trick is, how to take in less calories than you expend without being eaten alive by hunger–a subject I imagine we’ll end up discussing in the fullness of time.

MEMO TO THE BBC: Get the loading dock ready. There’s a big truckload of “Duh!” coming your way.

Don’t get me wrong, I’m always glad when stories appear in the press pointing out that obesity is not simply a product of gluttony. I just get annoyed when this is portrayed as a revolutionary new discovery. It isn’t. We’ve know it for a long time. It’s simply that the news media (of which the BBC news service is at least ostensibly a part) has not done an effective job communicating the fact. Instead of doing real investigative journalism into the subject, they have been content to pass off to the public the expostulations of countless diet and exercise quacks, including that people are obese because they simply and irresponsibly eat too much.

Wrong.

Eating more calories than the body requires is part of the obesity phenomenon, but the situation is way more complicated than that, and it isn’t hard to tell why. Let’s do a little math:

1) Suppose that a particular 20-year old person needs to consume 2500 calories a day given his metabolism and level of exercise. (This is not at all unreasonable. The “2000-calorie recommended daily intake” that you read about on food labels is–for some unexplained reason–based on the calories consumed by the average post-menopausal woman. It is not representative of what a younger person or a male person needs to eat.)

2) Now suppose that the person actually eats 10% too many calories, or an extra 250 calories per day. Know how much weight the person will gain in a year?

3) 250 calories x 365 days = 91,250 calories. Since there are about 3550 calories per pound of body fat, the person would gain 25.7 lbs. in the course of a year.

4) Now let’s suppose that we project the trend into the future. Suppose that the person continues to eat 250 too many calories per day for a decade. At the end of ten years, when the person is 30, he will have gained 257 lbs. and can be expected to weigh between 400 and 500 lbs.

Know very many 30-year old people who weigh between 400 and 500 lbs?

Didn’t think so.

Even people who give no attention at all to their caloric intake (such people being legion) do not usually gain 26 pounds a year or end up weighing between 400 and 500 pounds by the time they are thirty.

The only possible explanation for this is that the great majority of people–even overweight people–are not overeating more than 250 calories a day.

Now let’s flip the situation around:

5) Suppose that the same 20-year old person underate by 250 calories per day? How many pounds would he lose in a year? That’s right 25.7.

6) And what would happen in a decade? He’d be dead.

If he were magically able to continue losing weight evenly throughout the decade, he would have exhausted his entire body mass before the decade was up. In reality, though, unless you are The Incredible Shrinking Man, you can’t continue to lose body mass indefinitely. You’d probably die around the time you hit 70-90 lbs.

This means that people do not undereat by more than 250 calories per day, either.

Except for a the rare cases of a few individuals who starve themselves to death or who gain 250 pounds in a decade, most people consistently stay within an average of 250 calories of where the number they need to metabolize each day or within about 10% of the needed amount.

Further, even people who give no attention at all to their diet do this. The only conclusion is that there is a mechanism in the human body that pushes us to stay within that range of our needed caloric intake. (In actuality, the range is narrower than I have indicated, but I wanted to use simple obvious numbers to make the point.) Our bodies have a “weight regulator” fuction that works like a thermostat, keeping our caloric intake within a modest range of the number of calories we need per day.

From a phenomenological perspective, the tools the body uses to keep us in that range are feelings of hunger and satiety. When the body wants to jack up our calorie intake, it hits us with feelings of hunger. When it wants to tamp down our calorie intake, it hits us with feelings of satiety.

This means that the great majority of overweight people are not simply gluttonously sucking down food. If they were, their weight would quickly spiral out of control and keep going up until they died. Instead, they are simply eating when their body tells them to eat and not eating when it tells them to stop. In other words, they are responding to the biological imperative that is implanted in them.

Now, for obese people something has obviously gone wrong with the situation or they wouldn’t be overweight, but for most the problem is not the vice of gluttony. They are simply doing what their body is telling them to do.

I don’t have space in this blog entry to talk about what has gone wrong or how it can be fixed, but I’ll be happy to do so if folks want me to.

For now, we need to bear the above in mind when we are tempted to look down on people who are overweight–or who are more simply overweight than we are. Unless they’re experiencing rapid weight gain at the moment, they’re not eating beyond what their bodies are asking them to.

MEMO TO THE BBC: Get the loading dock ready. There’s a big truckload of “Duh!” coming your way.

Don’t get me wrong, I’m always glad when stories appear in the press pointing out that obesity is not simply a product of gluttony. I just get annoyed when this is portrayed as a revolutionary new discovery. It isn’t. We’ve know it for a long time. It’s simply that the news media (of which the BBC news service is at least ostensibly a part) has not done an effective job communicating the fact. Instead of doing real investigative journalism into the subject, they have been content to pass off to the public the expostulations of countless diet and exercise quacks, including that people are obese because they simply and irresponsibly eat too much.

Wrong.

Eating more calories than the body requires is part of the obesity phenomenon, but the situation is way more complicated than that, and it isn’t hard to tell why. Let’s do a little math:

1) Suppose that a particular 20-year old person needs to consume 2500 calories a day given his metabolism and level of exercise. (This is not at all unreasonable. The “2000-calorie recommended daily intake” that you read about on food labels is–for some unexplained reason–based on the calories consumed by the average post-menopausal woman. It is not representative of what a younger person or a male person needs to eat.)

2) Now suppose that the person actually eats 10% too many calories, or an extra 250 calories per day. Know how much weight the person will gain in a year?

3) 250 calories x 365 days = 91,250 calories. Since there are about 3550 calories per pound of body fat, the person would gain 25.7 lbs. in the course of a year.

4) Now let’s suppose that we project the trend into the future. Suppose that the person continues to eat 250 too many calories per day for a decade. At the end of ten years, when the person is 30, he will have gained 257 lbs. and can be expected to weigh between 400 and 500 lbs.

Know very many 30-year old people who weigh between 400 and 500 lbs?

Didn’t think so.

Even people who give no attention at all to their caloric intake (such people being legion) do not usually gain 26 pounds a year or end up weighing between 400 and 500 pounds by the time they are thirty.

The only possible explanation for this is that the great majority of people–even overweight people–are not overeating more than 250 calories a day.

Now let’s flip the situation around:

5) Suppose that the same 20-year old person underate by 250 calories per day? How many pounds would he lose in a year? That’s right 25.7.

6) And what would happen in a decade? He’d be dead.

If he were magically able to continue losing weight evenly throughout the decade, he would have exhausted his entire body mass before the decade was up. In reality, though, unless you are The Incredible Shrinking Man, you can’t continue to lose body mass indefinitely. You’d probably die around the time you hit 70-90 lbs.

This means that people do not undereat by more than 250 calories per day, either.

Except for a the rare cases of a few individuals who starve themselves to death or who gain 250 pounds in a decade, most people consistently stay within an average of 250 calories of where the number they need to metabolize each day or within about 10% of the needed amount.

Further, even people who give no attention at all to their diet do this. The only conclusion is that there is a mechanism in the human body that pushes us to stay within that range of our needed caloric intake. (In actuality, the range is narrower than I have indicated, but I wanted to use simple obvious numbers to make the point.) Our bodies have a “weight regulator” fuction that works like a thermostat, keeping our caloric intake within a modest range of the number of calories we need per day.

From a phenomenological perspective, the tools the body uses to keep us in that range are feelings of hunger and satiety. When the body wants to jack up our calorie intake, it hits us with feelings of hunger. When it wants to tamp down our calorie intake, it hits us with feelings of satiety.

This means that the great majority of overweight people are not simply gluttonously sucking down food. If they were, their weight would quickly spiral out of control and keep going up until they died. Instead, they are simply eating when their body tells them to eat and not eating when it tells them to stop. In other words, they are responding to the biological imperative that is implanted in them.

Now, for obese people something has obviously gone wrong with the situation or they wouldn’t be overweight, but for most the problem is not the vice of gluttony. They are simply doing what their body is telling them to do.

I don’t have space in this blog entry to talk about what has gone wrong or how it can be fixed, but I’ll be happy to do so if folks want me to.

For now, we need to bear the above in mind when we are tempted to look down on people who are overweight–or who are more simply overweight than we are. Unless they’re experiencing rapid weight gain at the moment, they’re not eating beyond what their bodies are asking them to.