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PART I
The Greatest Story Ever Sold
Chapter 2
A Calorie Is a Calorie – or Is It?
Оглавление“If folks want to maintain a healthy weight, they have to be sensitive to the calories in and calories out…Not every calorie is the same.”
Governor Tom Vilsack (D-Iowa), U.S. Secretary of Agriculture, upon release of the 2010 Dietary Guidelines, January 13, 2011
Wait a second. If people have to be sensitive to calories in and out, then why aren’t calories the same? Does anyone see the contradiction here? This was the first time that any government official had even remotely hinted that calories might not be interchangeable, and it was buried in this cryptic double-speak.
Everyone is a dietitian. Everyone thinks he or she understands obesity. Believe it or not, this is one of the harder medical conditions to comprehend. Why? Obesity is a combination of several factors: physics, biochemistry, endocrinology, neuroscience, psychology, sociology, and environmental health, all rolled up into one problem. The factors that drive the obesity pandemic are almost as myriad as the number of people who suffer from it.
The Venus Von Willendorf is an eleven-inch statue carbon-dated to 22,000 BCE that was unearthed in Austria in 1908 (see figure 2.1). It depicts the torso of a morbidly obese adult woman. This shows us that the ancients knew about obesity long before they knew about fast food. There are other ways to gain weight aside from potato chips and pizza, soda and suds. The medical literature lists at least thirty diagnoses that include obesity as a symptom. These include problems of the brain, liver, and adipose (fat) tissue; genetic disorders; various hormonal imbalances; and the effects of certain medications.
But none of these medical causes explain what’s happened to the world’s population over the last thirty years. Until 1980, statistically only 15 percent of the adult population had a body mass index – or BMI, an indicator of body fatness that is calculated from a person’s weight and height – above the eighty-fifth percentile, indicating either overweight or obesity. Now that statistic is 55 percent. And by 2030 it’s expected to be 65 percent.[8] Something’s happened in the last thirty years, but what?
Fig. 2.1. A Venus FatTrap. The Venus von Willendorf is an 11-cm-high statuette of a female that carbon-dates to between 24,000 and 22,000 BCE. It was discovered in 1908 in Austria, and is on display in the Naturhistorisches Museum in Vienna. It shows that obesity is as old as man (or woman) himself.
The First Law
In order to understand obesity, and energy balance in general, we must acquaint ourselves with the first law of thermodynamics, which states, “The total energy inside a closed system remains constant.” For you math and science geeks:
U = Q – W
where U is the internal energy of a system, Q is the heat supplied by the system, and W is the work done by the system. Work and heat are due to processes that either add or subtract energy; when work = heat, the internal energy stays constant. The first law is a law. It is elegant and airtight. If you don’t like it, file a grievance with Sir Isaac Newton. I subscribe to the first law. The basis for our current understanding of the causes and consequences of the obesity pandemic lies not with the first law itself, but rather in how you interpret it, for, as with all laws, there is plenty of room for alternative interpretations.
The prevailing wisdom on the first law can be summed up by one widely held dogma: a calorie is a calorie. That is, to maintain energy balance and body weight (the U in the equation), one calorie eaten (the Q) must be offset by one calorie burned (the W). The calorie eaten can come from anywhere, from meat to vegetables to cheesecake. The calorie burned can go to anywhere, from sleeping to watching TV to vigorous exercise. And from this dogma comes the standard and widely held interpretation of the first law: “If you eat it, you had better burn it, or you will store it.” In this interpretation, the behaviors of increased energy intake and decreased energy expenditure are primary (and presumably learned); therefore, the weight gained is a secondary result. Thus, obesity is routinely thought to be the natural consequence of these “aberrant behaviors.” As you will see hereafter, virtually all the stakeholders in the obesity pandemic have signed up on the side of personal responsibility.
The Seating Chart at the Table of Blame
The Head of the Table: The Gluttons and the Sloths
Personal responsibility occupies the biggest seat at the Table of Blame. The common assumption in obesity hinges on its being a personal choice: We control what we eat and how much we exercise. If you are obese, it must be because you chose to either eat more, exercise less, or both. Over the past twenty-five years, various government agencies have accumulated ample evidence of the increased caloric intake during that time frame, both in children and in adults. During this time, the CDC has documented that Americans have increased their caloric consumption by an extra 187 calories per day for men, 335 calories per day for women. The behaviors associated with the rise in obesity include increased consumption of sugar-sweetened beverages and decreased consumption of whole fruits, vegetables, and other sources of dietary fiber. On a societal level, obesity is also associated with less breastfeeding, skipped breakfasts, fewer family meals, and more fast food dining. Alternatively, a wealth of evidence supports a role for decreased physical activity and increased “screen time” (TV, computers, video games, and texting) in causing obesity.
It is from this perception of choice that we derive our current societal mantras around obesity: gluttony and sloth, two of the original “seven deadly sins.” I should note here that people exhibiting the other five deadly sins (greed, pride, lust, envy, and wrath) have gotten a pass in the press and in society as a whole. They are frequently extolled in the media – just watch the reality shows The Apprentice (envy, greed, pride, wrath—“You’re Fired!”), Millionaire Matchmaker (lust, greed, pride), or Jersey Shore (all known sins and then some).
We’ve found absolution for nearly every vice and sin we can commit, except for these two. They continue to defy our society’s ability to forgive. This despite the fact that 55 percent of Americans are either overweight or obese. Thin people are now in the minority, yet our culture continues to punish the majority. The average woman in the United States wears a size 14, yet many stores do not carry anything above a size 10. Although many women’s clothing stores now have “vanity sizes” (what was a size 10 in 1950 is now labeled a size 6), a large percentage of the population still can’t find anything on the rack. Approximately ten years ago in San Francisco, a billboard advertising the local 24-Hour Fitness health club depicted an extraterrestrial with the tag line “When they come, they’ll eat the fat ones first.”
Our society continues to glorify thinness even though it appears to be less achievable every year. Those of us who are overweight or obese are immediately assumed to be gluttons and/or sloths. The obese are passed over for employment because it’s assumed they’ll be as lazy on the job as they are in caring for their bodies. They are among the last groups about which you can still make pejorative comments in public. From this condemnation, it’s a quick jump to the determination that obese people became so due to a behavioral defect. This formulation serves many purposes. It certainly justifies society’s desire to place blame.
Even the obese have bought into the thesis of personal responsibility (see chapter 20). They would prefer to be portrayed as “perpetrator” rather than “victim.” If you’re a perpetrator, you maintain control and make your own choices, which is more hopeful than the alternative. If, instead, you’re a victim, you have no power, obesity is your fate, and there is no hope. You’re doomed, which is far more depressing. Finally, “personal responsibility” serves as the cornerstone of both the government’s and the insurance companies’ restriction of obesity care delivery.
Seat 2: The Health Insurance Industry
Much of the public views doctors as moneymaking mountebanks who care less for their patients than for their wallets. Well, we lose money on every patient we see. While our hospital’s general pediatric health insurance reimbursement averages 37.5 cents on the dollar (a pittance), our pediatric obesity clinic collects only 29.0 cents per dollar billed. The reason for this? The health insurance industry refuses to pay for obesity services, saying, “Obesity is a behavior, a flaw in your character, a psychological aberration. And we don’t pay for behavior.” This is the reason that, despite having enough business many times over, childhood obesity clinics and treatment programs are closing across the country. The insurance industry has decided that obesity is a lifestyle choice; therefore, it won’t pay. And when insurance companies do pay, they pay the absolute minimum.
The insurance industry hates this obesity epidemic almost as much as we doctors do. They are hunkering down for a long siege. Why do they continue to deny reimbursement for obesity services? Because if they paid for all the services required by today’s pandemic, it would break their piggybank. Instead, they keep plugging holes in the dike by ascribing blame to the individual. They know that if they ever admit that obesity is the fault of no one person, the waters will engulf them all.
Seat 3: The Medical Profession
Twenty years ago, obesity was a social issue, not a medical one. At the beginning of my career, a colleague in pediatric endocrinology (the study of hormones in children) would send a form letter to the parents of children referred for obesity that read, “Dear parent, thank you for your interest in our pediatric endocrinology division. Your child has been referred for obesity. Obesity is a problem of nutrition and activity, not one of endocrinology. We suggest that you seek general advice from your child’s pediatrician.” And despite the undeniable onslaught of patients referred, many of my colleagues still feel this way.
As the problems have soared and the research dollars have poured in, the American Diabetes Association (ADA), the American Heart Association (AHA), and countless others professional organizations have devoted a substantial portion of their agendas to the obesity pandemic. The standard mantra espoused by the medical establishment is, “Lifestyle causes obesity, and obesity causes metabolic syndrome.” We doctors recognize our role in mitigating the negative effects of obesity. But, again, for most physicians, the behaviors come first. The fault still lies with the patient.
Seat 4: The Obesity Profiteers
They say, “You’re weak. You’ve failed. Let us help you.” They profess to have the answer for your obesity problem and are peddling one solution or another. They are the obesity profiteers, and they represent large and vast industries, most of which are ostensibly trying to “do the right thing,” while making a fortune in the process. We have the otherwise reputable peer-group weight-loss programs such as Weight Watchers and Jenny Craig, which strongly recommend the option of buying their trademarked cuisine (often loaded with sodium) to bolster profits. There are the diet supplement people such as Nutri-System, who demand that you purchase their food if you want to see results. Gym programs such as Curves and 24-Hour Fitness charge initiation and renewal fees for membership. Then there are the companies that make home exercise equipment. Their late-night infomercials invariably show a buff guy stretching a rubber band with the implicit message, “You can look like this if you stretch a rubber band.” And then we have the “obesity authors” (gee, I’m one now!). Some are M.D.s, some Ph.D.s, some journalists, some pop culture phenomena, and some charlatans (none of which is mutually exclusive). All profess to have the answer to your obesity problem, peddling one diet or another. A few of these authors have developed corporations that want to sell you their food line, such as Atkins or the Zone. And each provides just enough science and nuggets of truth to hook the public.
Some weight-loss doctors and clinics peddle prescription appetite suppressants or other weight-loss remedies – all of which are paid for out of pocket. Some of these doctors are reputable and brilliant academics at medical universities who are trying to save people’s lives while studying the physiology of obesity. Some are surgeons who perform liposuction for cosmetic purposes and bariatric surgery for metabolic and cardiac rescue. But some of them are “cut-and-run” surgeons operating out of small airplanes and flying around to little towns to perform quickie lap-band surgeries or gastric bypasses. They take their victims’ money, have no quality control, never see the patient in follow-up, and sometimes leave medical catastrophes in their wake.
While the insurance companies refuse to shell out funds for this problem, the research money is pouring in. The pharmaceutical industry has spent a lot of money to come up with the “obesity blockbuster,” that magic bullet that will work long-term and for everyone. But that’s a pipe dream because, first, obesity isn’t one disease, it’s many; second, our bodies have many redundant pathways to maintain our critical energy balance, so one drug can’t possibly be effective for everyone; and third, there’s no one drug that will treat metabolic syndrome (see chapter 19).
Each of these people and industries have one thing in common: they are trying to make a buck off the misfortunes of the obese, to the tune of $117 billion a year. And they’re all charging retail. Out of pocket, cash on the barrelhead. No insurance reimbursements here. No discounts. In case you hadn’t noticed, the obese will do anything not to be obese, even throw their money away on “get-thin-quick” schemes. That’s why these industries are the obesity profiteers. Do any of their “solutions” work? Fat chance. If you just did what they told you, the fat would magically disappear. If it fails, it’s your fault – you must have been noncompliant! Yet another reason for the obese to be depressed. Think about it – if any of these books, diets, or programs actually worked for the entire population, there would be only one. The person who makes this discovery will likely win the Nobel Prize, move to a mansion in Tahiti, and be featured on Lifestyles of the Rich and Famous.
Seat 5: The Fat Activists
There’s nothing socially or medically wrong with being fit and fat; you’re doing better than the people out there who are thin and sedentary. But there is something medically wrong with being fat and sick. Especially if you’re suffering metabolically, which 80 percent of obese people are. If you fall into this category, you are costing society money in caring for your metabolic illnesses, reducing productivity, and clogging up (and bringing down) the health care system. Not to mention digging yourself an early grave! The vocal proponents for the political and social rights of the obese, primarily the National Association to Advance Fat Acceptance (NAAFA), say, “Being fat is a badge of honor. Be fit and fat, be fat and proud.” No victimization here. And I agree. But NAAFA is also opposed to academic obesity research where its primary goal is weight loss – because why would you investigate a condition that is totally normal? They don’t think attention should be paid to how much kids weigh. This is puzzling to me. There is something highly paradoxical about enabling your child to be fat and sick. The majority of obese kids will be diabetic and cardiac cripples by the time they’re fifty. The science and research that NAAFA’s policy would seem to exclude are critical to studying this epidemic and determining what we can do about it. It’s my job as a pediatrician to protect these kids from such misguided thinking.
Seat 6: The Commercial Food Industry
The commercial food industry responds to the obesity pandemic with two mantras. First, “Everyone is responsible for what goes into his or her mouth.” Is that true? What goes into our mouths depends on two things: selectivity and access. Second, “Any food can be part of a balanced diet.” True but irrelevant because, thanks to the food industry, we don’t have a balanced diet, and they’re the ones that unbalanced it. They are a major instigator of the obesity pandemic through both their actions and the kind of rhetoric they use to justify those actions. Corporations repeatedly say one thing, yet do another. McDonald’s now advertises a healthier menu, with commercials featuring slim people in exercise clothes eating salads. However, the vast majority of people entering McDonald’s, even if they come in with the idea of eating a salad, instead order a Big Mac and fries. And McDonald’s is well aware of this. Its recent billboard campaign, “Crafted for Your Craving,” says all you need to know. Carl’s Jr.’s promotion of the “Western Bacon Six Dollar Burger,” which has a whopping 1,030 calories and 55 grams of fat, generally depicts fit and attractive people consuming the company’s fare with relish. Do you really think they would continue to be thin if they ate this on a regular basis?
Food has become a commodity (see chapter 21), with foodstuffs that can be stored being traded on the various commodities exchanges. Speculators can corner the market on anything, from pork bellies to orange juice, by betting how much the price will rise and fall. And it’s because individual foods are treated as commodities that the downstream effects of changes in the food supply, and subsequently food prices, are being felt worldwide (see chapter 21). Cheap food means political stability. There is an imperative to keep food highly available and the prices as low as possible. Everyone is for cheap food. The United States spends 7 percent of its gross domestic product (GDP) on food, which allows the populace to buy more DVDs and iPads and take more vacations. But cheaper food, loaded with preservatives for longer shelf life, costs you on the tail end, and way more than all your gadgets and vacations put together (with interest).
Seat 7: The Federal Government
Our government is extraordinarily conflicted about where it should stand on the obesity pandemic. In 2003, former U.S. surgeon general Richard Carmona stated that obesity was an issue of national security, a stance that current surgeon general Regina Benjamin has upheld (despite the fact that she herself is obese) and one to which the U.S. Army has signed on. The public health branches of the government tell us that we eat too much and exercise too little. Mrs. Obama’s Let’s Move! campaign centers on the idea that childhood obesity can be battled by planting school vegetable gardens, encouraging kids to get out and exercise, and remaking the School Nutrition Act. All necessary, but not sufficient.
The U.S. government does everything it can to keep food cheap (see chapter 16). The USDA has chosen not to accept any responsibility for its role in the obesity pandemic, continuing to market our Western diet around the world. The Farm Bill (see chapter 21) maintains food subsidies to keep farmers employed and growing more crops. The growers make their profits on volume. The food processors make big markups and pass them along to the consumer. And the USDA subsidizes food entitlement programs to the poor, such as the Supplemental Nutrition Assistance Program (SNAP, formerly known as food stamps) and the Women, Infants, and Children nutrition program (or WIC, which supplies low-income infants and their mothers with food and health care), to keep them alive and complacent. Until 2007, WIC bowed to the pressure of food lobbyists. The foodstuffs provided were largely unhealthy, and included white bread and high-sugar juices.
The “Food Pyramid,” the federal nutrition guide released in 1974 (see figure 2.2a) and revised every five years, cultimating with “MyPyramid” in 2005, was never based on science. Indeed it was top and bottom heavy – hardly a pyramid. In response to calls for revision from many in the medical community, the Food Pyramid was deep-sixed in 2011. “MyPyramid” has now morphed into “MyPlate” (see figure 2.2b). The most recent guidance from the Dietary Guidelines Advisory Committee (DGAC), released in 2010, says that obesity is a problem (shocker) so we should all eat less fat, sugar, and salt. We’re all supposed to eat more fruits and vegetables, and less of everything else. This is stating the obvious. Don’t we already know this? Eat less? How? If we could eat less, there wouldn’t be an obesity pandemic. But we can’t.
Fig. 2.2a. The Ancient Pyramids. The traditional USDA Food Pyramid, circa 2005, which advised us to eat more grains and less fat and sugar. Alongside it, what Americans actually ate – more like an hourglass than a pyramid.
Fig. 2.2b. The Modern Merry-Go-Round. Under pressure from consumer groups and in response to the emerging science, the Pyramid was relegated to ancient history, and MyPlate was adopted by the USDA in 2011. MyPlate advises us to eat approximately half a plate of vegetables or fruits, one quarter fiber-containing starch such as brown rice, and one quarter protein, preferably low-fat. It’s too early to tell if this change will have any effect on American eating habits.
Each of the stakeholders in the obesity pandemic is singing the same tune: “Your obesity is your personal responsibility, it’s your fault, and you’ve failed.” And all these accusations are a variation on a theme based on one unflappable dogma: a calorie is a calorie.
Calories Don’t Count If…
The clues are all around us as to what’s really happened. It’s time to look at where those extra calories went, because it is in these data that we will find the answer to the obesity dilemma.
There are three problems with “a calorie is a calorie.”
First, there is no way anyone could actually burn off the calories supplied by our current food supply. A chocolate chip cookie has the equivalent calories of twenty minutes of jogging, and working off a Big Mac would require four hours of biking. But, wait! Olympic swimmer Michael Phelps eats 12,000 calories a day and burns them off, right? If this were the case for all of us, diet and exercise should work – you’d burn more than you ate and lose weight (see chapter 13). And diet drugs should work – you take the drug, eat or absorb less, and lose the pounds. Except the meds don’t deliver on their promises. They work for a brief period, and then patients reach a plateau in weight loss (see chapter 4).[9] Why? Do the patients stop taking the pills? No. So why do the medications stop working? The answer: because the body is smarter than the brain is. Energy expenditure is reduced to meet the decreased energy intake. So a calorie is not really a calorie, because your caloric output is controlled by your body and is dependent on the quantity and the quality of the calories ingested.
Second, if a calorie is a calorie, then all fats would be the same because they’d each release 9.0 calories per gram of energy when burned. But they’re not all the same. There are good fats (which have valuable properties, such as being anti-inflammatory) and bad fats (which can cause heart disease and fatty liver disease; see chapter 10). Likewise, all proteins and amino acids should be the same, since they release 4.1 calories per gram of energy when burned. Except that we have high-quality protein (such as egg protein), which may reduce appetite, and we have low-quality protein (hamburger meat), which is full of branched-chain amino acids (see chapter 9), which has been associated with insulin resistance and metabolic syndrome.[10] Finally, all carbohydrates should be the same, since they also release 4.1 calories per gram of energy when burned. But they’re not. A closer look at the specific breakdown of the carbohydrate data reveals something interesting. There are two classes of carbohydrate: starch and sugar. Starch is made up of glucose only, which is not very sweet and which every cell in the body can use for energy. Although there are several other “sugars” (glucose, galactose, maltose, and lactose), when I talk about sugar here (and in the rest of this book), I am talking about the “sweet” stuff, sucrose and high-fructose corn syrup, which both contain the molecule fructose. Fructose is very sweet and is inevitably metabolized to fat (see chapter 11). It is the primary (although not the sole) villain, the Darth Vader of the Empire, beckoning you to the dark side in this sordid tale.
The third problem with “a calorie is a calorie” is illustrated by the U.S. secretary of health and human services Tommy Thompson’s admonishment in 2004 that we’re “eating too damn much,” would suggest that we’re eating more of everything. But we’re not eating more of everything. We’re eating more of some things and less of others. And it is in those “some things” that we will find our answer to the obesity pandemic. The U.S. Department of Agriculture keeps track of nutrient disappearance. These data show that total consumption of protein and fat remained relatively constant as the obesity pandemic accelerated. Yet, due to the “low-fat” directives in the 1980s of the AMA, AHA, and USDA, the intake of fat declined as a percentage of total calories (from 40 percent to 30 percent). Protein intake remained relatively constant at 15 percent. But if total calories increased, yet the total consumption of fat was unchanged, that means something had to go up. Examination of the carbohydrate data provides the answer. As a percentage of total caloric intake, the intake of carbohydrates increased from 40 percent to 55 percent.[11] While it’s true we are eating more of both classes of carbohydrate (starch and sugar), our total starch intake has risen from just 49 to 51 percent of calories. Yet our fructose intake has increased from 8 percent to 12 percent to, in some cases (especially among children), 15 percent of total calories. So it stands to reason that what we’re eating more of is sugar, specifically fructose. Our consumption of fructose has doubled in the past thirty years and has increased sixfold in the last century. The answer to our global dilemma lies in understanding the causes and effects of this change in our diet.
There’s one lesson to conclude from these three contradictions to the current dogma. A calorie is not a calorie. Rather, perhaps the dogma should be restated thus: a calorie burned is a calorie burned, but a calorie eaten is not a calorie eaten. And therein lies the key to understanding the obesity pandemic. The quality of what we eat determines the quantity. It also determines our desire to burn it. And personal responsibility? Just another urban myth to be busted by real science.
8
S. L. Gortmaker et al., “Changing the Future of Obesity: Science, Policy, and Action,” Lancet 378 (2011) 838–47.
9
R. Padwal et al., “Long-Term Pharmacotherapy for Obesity and Overweight,” Cochrane Database Syst. Rev., Art. No.: CD004094. DOI: 10.1002/14651858 (2004). PMID: 15266516.
10
C. B. Newgard et al., “A Branched-Chain Amino Acid-Related Metabolic Signature That Differentiates Obese and Lean Humans and Contributes to Insulin Resistance,” Cell Metab. 9 (2009): 311–26.
11
P. Chanmugam et al., “Did Fat Intake in the United States Really Decline Between 1989–1991 and 1994–1996?” J. Am. Diet. Assoc. 103 (2003): 867–72.