Living Low Carb (20 page)

If I’m running late and in a hurry, I get a lot less gas mileage than normal. I race up to stoplights, slam on the brakes, floor the accelerator when the light changes—all activities that minimize gas mileage, but get me wherever I’m going a little sooner.

In other words, you can’t predict the mileage just from knowing how many gallons of gas are in the tank. You have to also know how the car is going to be driven—or, in the case of calories and the body, how the body is going to process those calories. And all calories are not processed in the same way. This is the basis of the metabolic advantage.

More than a few studies have raised questions about the whole “
calorie is a calorie
” orthodoxy. At Cincinnati Hospital, Dr. Bonnie Brehm put two groups of obese women on diets: one was put on Atkins Induction (very low-carb), the other was put on a conventional low-fat high-carb diet. The Atkins dieters lost more weight
even though both groups tended to consume the same number of calories
. Dr. Stephen Sondike did a similar study with two groups of obese teenaged boys—the Atkins dieters consumed an average of 1,800 calories, while the low-fat kids took in 1,100. Guess who lost more.

Now, it’s also true that in a lot of studies where one group is on a lowcarb diet and the other is on a conventional diet, the low-carb folks lose more weight at first (like for the first 4–6 months), but the differences often even out over time (like after a year). We’ll get to the reasons for that in a moment.

First, let’s demolish the idea that being able to eat somewhat more calories on a carb-restricted diet and still lose weight violates the sacred “First Law of Thermodynamics.” Which it seems to do.

The operative word here is “
seem
.” But if you ask people who actually
understand
the laws of thermodynamics, you come up with a quite different take on it. According to a paper published by Richard Feinman, PhD, professor of biochemistry at the SUNY Downstate Medical Center and founder of the Nutrition and Metabolism Society, it appears that the naysayers may not understand thermodynamics nearly as well as they think they do.

The naysayers don’t account for
another
part of the laws of thermodynamics which basically talks about waste and inefficiency (see Mike Eades’s driving experiences above). Turns out, lots of calories are actually
wasted
during the processes of metabolism, and some calories tend to be wasted more than others. That’s because some forms of “energy” (calories) are more
efficient
; glucose molecules, for example, tend to be used for energy right away. They’re like coins you have in your pocket—easier and faster to use than if you have to go to the ATM to get your cash. If you’re using mainly protein and fat for fuel, it’s like having to go to the ATM. You still use cash, but you’ve wasted a lot of time (and energy) converting that ATM swipe into something the clerk at the cash-only supermarket will accept. Those extra calories that low-carbers may consume don’t actually “disappear” at all—they’re just “burned” in the process of being converted to usable fuel for the body.

Here’s how it works. Suppose you have two similar cars, with equal size gas tanks and engines, about to depart on a trip of a given distance, neither of which has Mike Eades at the wheel. Both have to go through the same toll booths and obey the same speed limits. However, one driver is given “exact-change tokens” to drop in the toll-booth basket as she cruises by. The other driver is given a stack of $50 bills and told she has to use one at every single booth. Who do you think is going to get to the destination first?

You see, driving through the toll booth with the exact-change tokens is very
efficient
. But driving through with $50 bills is not. A lot of time and energy is
wasted
—you have to stop the car for a minute, wait for the change, count out the money, and finally put the token in the basket before you can get started again.

In their paper “Thermodynamic Edge for Low Carbohydrate Diets,” Feinman and his colleague Eugene J. Fine, PhD, explain that the same thing is true on low-carb diets. Carbohydrate is an
efficient
fuel; it’s like having exact-change tokens. Protein and fat, on the other hand, is more like having $50 bills. To turn it into tokens takes energy (burns calories), and it is this “wasted” energy that accounts for what we might call “the metabolic advantage.”

And that extra waste is precisely what allows people on very-low-carb diets to consume
somewhat
more calories than they did on low-fat, high-carb diets, and still lose weight.

As Dr. Feinman puts it, “The human body is a machine and the efficiency of the machine is controlled by hormones and enzymes. Carbohydrates increase insulin and other hormones that regulate enzymes, leading to storage rather than burning of fat.”

I mentioned earlier that a number of studies showed that low-carb diets have an advantage right out of the starting gate, when compared with conventional diets for weight loss. Time and again, we see low-carbers beating the competition at the six-month mark, only to see no substantial difference between the two groups by the end of a year or two. Why does this happen?

I don’t know, but I have a theory.

I think what happens is this: People do really well on their “protein and fat” carb-limited program, and stick with it pretty religiously for a few months. Then they get complacent. They think, hey, things are going pretty good, maybe I can add some carbs back. Before you know it, they’re eating that same “meat and eggs” breakfast, but now they’ve got a few slices of toast with it, and maybe a glass of orange juice. They’re back to a high-calorie “mixed” diet, even though they’re still technically being treated by the researchers as members of the “low-carb” group. It’s no surprise that these folks gain their lost weight back. It’s actually a tribute to how well low-carb does that even staying on it even a
little
produces better results than not staying on it at all.

Take the famous “A to Z” diet study done in 2007 at Stanford University.
¹
Back in March of that year, you couldn’t swing a bat without seeing a headline somewhere about this study, a year-long affair that compared four diets. “Atkins beats Zone, Ornish and U.S. diet advice,” proclaimed CNN. “Atkins Diet Tops Others In Study,” said the
Washington Post
. The study got a lot of press and generated a fair amount of controversy. It was also the subject of a fair amount of misinterpretation in the press. But what actually happened has a lot to tell us about dieting in general.

First, some background: Researchers at Stanford University took 311 premenopausal women, all of them overweight or obese, and assigned them to four diet groups: Atkins, Ornish, the Zone, and the LEARN plan, a conventional-eating program based on U.S. dietary guidelines. “We wanted a range of diets from high carbohydrate to low,” explained lead researcher Christopher Gardner, PhD. The Atkins diet, of course, is famously low in carbohydrates (and can be high in either fat, protein, or both). The Ornish diet is extremely low in fat (about 10% of intake); and the Zone is right in the middle (technically, 40% of the diet comes from carbs and 30% each from protein and fat; see page 258). The LEARN diet is based on conventional recommendations of about 55% to 65% carbs and less than 10% saturated fat.

The researchers were interested primarily in weight loss, though other measures were taken as well (more on that in a moment). “In the weight-loss department, there was a modest advantage for the Atkins group,” Dr. Gardner told me. Those in the Atkins group lost the most weight (10 pounds, on average); those in the Zone group lost the least (3.5 pounds, on average)—and the difference between the two was statistically significant.
²

But there were some problems. For one thing, the women in the study were far from meticulous about following the dietary regimen to which they were assigned. While the women in the Atkins group were aiming for between 20 and 50 grams of carbohydrate a day, by the end of the study they were eating well over 125 grams, which, while definitely less than the average American daily carb consumption, is nonetheless hardly a strict “lowcarb” diet. The Ornish group, meanwhile, aiming for 10% fat, was actually eating almost 30%. Zone dieters shooting for 30% protein wound up eating 20%, and even the women attempting to follow the conventional LEARN diet wound up reducing their carbs to just over 47%. Critics—including the designers of the diets that bore their name—complained loudly that the study results were not valid because the diet strategies under investigation had not been followed to the letter.

Well, maybe not. But as Dr. Gardner convincingly pointed out to me in an interview, this was a study of what people actually
do
with dietary advice. As such, it sheds a lot of light about “real-world” dieting. Here’s what Gardner said:

We purposely didn’t just hand them the diet book and tell them to come back in a year. We made sure they understood it. Each group had 8 weeks of classes with a dietitian who went over the principles of the books, section by section, so everyone knew exactly what to do. Furthermore, these were educated women in the Stanford University area—they were highly motivated and had a lot of support. For the last 10 months of the 12-month study, the women were left to follow the diets on their own without any additional support or guidance from staff. So what we’re seeing here, in terms of deviation from the exact principles of each diet, is a very ‘real-world’ scenario—it’s what happens when even motivated people follow diet books. We think that’s extremely relevant.

And so do I. If most of the women in this study—who were given information
and
support (including financial incentives for finishing)—couldn’t follow any of the diets to the letter, what chance do mere mortals have?

Not much. But that hardly means the study is irrelevant. In fact, it might be even
more
relevant because it’s representative of the way diets are actually followed in reality.

See, critics of the study missed a very important point: while the women may not have followed the diets to the letter, they
did
made changes in some important areas according to the
principles
of the respective plans. For example, the Atkins women had started the program consuming about 215 grams of carbohydrate a day (about 45% of their diet), which is still lower than average (the “average” American consumes about 300 grams a day or more, at least 50% of their diet). By the end of the 12 months, the women in the “Atkins group” were down to about 34%. That’s a big deal. Sure, it was higher than what was recommended for their group, but it was still a substantial change in the low-carb direction. They may not have achieved
perfection
, but they did achieve
results
, and those results shouldn’t be overlooked simply because the women didn’t follow the diets perfectly. After all, who can?

It’s also worth mentioning that the women in the Atkins group also improved a lot of other things besides their weight. Their HDL (“good”) cholesterol at 12 months was significantly higher for the Atkins group members than for the Ornish folks, and triglycerides were lower in the Atkins group than in the Zone group. In fact, triglycerides for the Atkins group went down by 29%, more than twice the percentage of any other group. And the decrease in average blood pressure for the Atkins group was significantly greater than any other. By the end of the 12-month study, LDL (“bad”) cholesterol, the type that many health professionals warned would worsen on the Atkins diet, was statistically about the same among the four diet groups. These are important findings, particularly in view of the negative press low-carbohydrate diets have gotten for their supposed bad effects on cardiovascular health. In this study, at least in the short term, the opposite appeared to be the case.

“
It’s increasingly clear that the average person may not be able to make huge shifts in their diet without a lot of help
,” Dr. Gardner said. “
You have to ask yourself, is the (diet) book too complicated? Or, do some people have certain limitations—physiological or psychological—that are just too difficult to overcome, even when they know what they are supposed to do? And then you have to look at the food environment we live in and the fact that there are constant messages about food that make it extraordinarily difficult to stay with any plan that is healthful and suggests limitations on the amount you eat
.” A person aiming for 10% fat who works in an office where the only available food is standard cafeteria-and-snackmachine fare doesn’t get a lot of support for staying on their plan.

So what’s the take-away? “
I think one advantage that the Atkins diet had was the simplicity of the message,
” Dr. Gardner told me. “
A lot of people say that the main Atkins message is to eat all the steak and brie that you want, but that’s not it. Their main message is this: you can’t have any refined sugar. None. No soda, no white bread, no high-fructose corn syrup. It’s simple and direct and easy to understand, and I think it may turn out to be one of the most important messages of all
.”

The bottom line is this: you can lose weight on low-carb; but if you want to keep losing, you need to stay on the program. You can also lose weight on a “regular” diet, but guess what: you
also
have to stay on the program. (In case you hadn’t noticed, there’s really no way around staying with the program, whatever the program is!)

So now the question becomes: how easy is it to stay with the program?

And the answer is: it depends on the person. Or, more accurately, on the “match” between person and program.

For many people with blood-sugar issues, “staying on the program” is going to be a whole lot easier on low-carb. That doesn’t mean you can’t get results on the standard low-fat regimen—obviously people do, just as they do on raw foods, on vegan diets, and on mixed diets. But not if it’s highcalorie, and not if they don’t stick with it. For many people, lower carb intakes mean
fewer
blood-sugar fluctuations,
fewer
cravings, and
better
bloodlipid profiles (since glucose and insulin are better managed, and triglycerides are always lowered). Many people find it easier to manage their appetite on low-carb.