Santa baby, just slip sustainable aquaculture
under the tree, for me.
Been an awful good girl, Santa baby,
So hurry down the chimney tonight.

From flickr user duluoz cats

Dear Santa,

I know I can be a bit of a “negative Nancy.” I spend a lot more time criticizing existing policy and reform efforts than offering alternatives or solutions. Of course, that’s partially due to the fact that not all policies need alternatives—the flip side of a lot of my apparent negativity is that I have a much sunnier outlook on the U.S. food system than many self-identified foodies and people associated with the “food revolution.”

For example, I’m down on most anti-obesity initiatives because I don’t think obesity causes serious diseases or death. I’m open to evidence to the contrary, but in all the epidemiological studies I’ve seen (including the ones cited by the WHO and NIH when they redefined “obesity” to a lower BMI range) BMI isn’t even significantly correlated with an increased risk of mortality until you get into the territory of severe or morbid obesity (BMI 35+). The number of Americans in that category has been growing since 1980, but it still amounts to less than 5% of the U.S. population, far less than the 30-60% of overweight or obese Americans usually cited as the evidence that we’re in the midst of an obesity “epidemic.” Americans on average aren’t much fatter than they were 50 or 100 years ago. The “typical American diet” high in refined grains and sugar probably isn’t optimal for human health (for reasons other than that it makes most people fatter), but it nonetheless enables many people to live long, relatively healthy lives.

From Found in Mom’s Basement.

I think we’re doing somewhere between okay and great on several other fronts, too. Although imperfect in many ways, the industrial food production and distribution systems are sometimes more efficient in terms of total inputs and carbon emissions per calorie or pound than small, local farms—environmentalists should celebrate the spread of no-till farming and possibility of safe GMO crops that increase yields with reduced water, nitrogen, or phosphorus needs. Illnesses caused by food-borne pathogens are probably less common now than at any point in our country’s history (and new estimates about the incidence of food-borne illness are even lower). For anyone who’s interested in novel foods, there’s probably never been a better time or place to be an eater. The ever-increasing flows of people, goods, and information around the world have made everything from far-flung regional specialties to ancient recipes to innovative taste experiences more available to more consumers than ever.

Of course, that doesn’t mean things couldn’t be better. So here’s a list of seven changes I would like to see in how people produce, consume, regulate, and talk about food in the U.S. It’s a bit of a motley assortment—if there’s one thing people in the “food movement” seem to agree on it’s that food is implicated in our lives in a myriad of interconnected ways. I think there’s room for improvement in multiple realms. 

From flickr user HA! Designs Read more

Previously in this series: Intro, Part I, and Part II.

 Oprah 2005/2009

To test whether turning [fat people] into thin people actually improves their health, or is instead the equivalent of giving bald men hair implants, it would be necessary to take a statistically significant group of fat people, make them thin, and then keep them thin for long enough to see whether or not their overall health then mirrored that of people who were physiologically inclined to be thin. No one has ever successfully conducted such a study, for a very simple reason: No one knows how to turn fat people into thin people.
—Paul Campos, The Obesity Myth (2004)

Diets do cause weight loss…in the short term

People who think calorie restriction dieting “works” haven’t necessarily been duped by the diet industry or seduced by the prevailing nutritional “common sense” that weight loss and gain are a simple matter of calories in vs. calories out. Many of them believe it because their personal experience seems to confirm it, often repeatedly. Of course, “repeatedly” is part of the problem. Weight cycling—losing and re-gaining 5% or more of one’s total body weight—isn’t what dieters or public health policy makers are shooting for. Even people dieting with a specific occasion in mind, like a wedding or a high school reunion, would generally prefer to achieve permanent weight-loss.

But almost a century of research has shown that dieting—which usually involves calorie restriction—is not the way to do that. Studies repeatedly find that while eating less causes weight-loss in the short term, a majority of participants in weight-loss interventions focused on diet gain most of the weight back within 1 year and the vast majority (90-95%) gain all of it back within 3-5 years. Approximately 30% gain back more than they initially lost, and there’s some evidence that people who’ve lost and regained weight have more health problems than people who weigh the same, but have never lost and regained a significant amount of weight.

This is not controversial. Virtually every study of weight-loss dieting that has followed participants for longer than 6 months has found that the majority of dieters regain all the weight they lose initially, if not more. In other words, Oprah’s high-profile weight fluctuations are not the unfortunate exception to most dieters’ experience, they are the rule. A gallery of pictures of Oprah through the years illustrates the most frequent and reliable outcome of dieting:

             1985                           1988                             1992                             1996

              2001                            2005                          2008                            2010        

I am not concerned (in this entry) with why calorie restriction diets fail—there are competing theories and perhaps I’ll try to tackle them some other time. However, when it comes to evaluating public health policies aimed at the general population, like posting calorie counts on menus, it doesn’t really matter why the kind of behavior it’s designed to encourage fails, especially when it fails so spectacularly. Whether the problem is that 90-95% of people don’t have the willpower to stick to calorie-restricted diets or that most peoples’ metabolic rates eventually adjust or both or something else entirely, continuing to prescribe calorie restriction to individuals seeking to lose weight is futile at best. Given the health problems associated with weight cycling and psychological distress caused by diet “failure,” it’s probably also dangerous and cruel. More on that another day, too.

The goal of this entry is to provide a condensed-but-comprehensive overview of the evidence that convinced me that weight-loss dieting—and particularly calorie-restriction dieting or eating less—does not “work” for most people. By “work” I mean lead to significant weight loss—at least 10% of starting body weight—that lasts for more than 3 years (in keeping with the clinical definition of “weight loss success” proposed by the 1998 National Heart, Lung, and Blood Institute [NHLBI] Obesity Education Initiative Expert Panel proposed). I honestly tried to keep this as short as possible and bolded the “highlights” if you want to skim. However, if brevity is what you’re looking for, see this 2007 Slate article. Read more

Introduction to this series here.

  When you see 450 posted, that might really mean 530. Or more.

Publishing caloric values right on the menu seems straightforward and transparent. The numbers offer what appears to be a simple way to compare items no matter how different they are based on what many people believe is, as Margo Wootan said, the “most critical piece of nutrition information.”  But even setting aside for a moment the issue of whether the number of calories should be the most important factor governing food choices or all calories are equal, there are problems with the numbers themselves.

Give or take 20%…but almost always give

According to a recent study at Tufts where a team of nutrition scientists led by Susan Roberts used a calorimeter to measure the actual caloric value of 39 prepared meals purchased at supermarkets and restaurant chains:

Measured energy values of 29 quick-serve and sit-down restaurant foods averaged 18% more than stated values, and measured energy values of 10 frozen meals purchased from supermarkets averaged 8% more than originally stated. Some individual restaurant items contained up to 200% of stated values and, in addition, free side dishes increased provided energy to an average of 245% of stated values for the entrees they accompanied. (Journal of the American Dietetic Association; full-text is subscription only—here if you have UM library permission)

As Roberts told Time, she decided to do the study because when she was trying to follow the diet advice in her own book, substituting prepared or restaurant meals, “the pounds stopped dropping off. Just as suspiciously, she always felt full” (more on the idea the fullness means a diet must be failing when I get to the issue of why calorie-restriction doesn’t work for long-term weight loss).

It’s worth noting that the results of the study didn’t reach statistical significance “due to considerable variability in the degree of underreporting.” However, they “substantially exceeded laboratory measurement error” and—as noted above—the average discrepancy was 8% or 18% higher, it didn’t even out. However, the average is actually within the Federal regulations—from the same Time article:

Federal regulations are strict about the accuracy of the net weight of a package of prepared food, which must be at least 99% of the advertised weight. When it comes to calories, the count can be a far bigger 20% off. The Federal Government plays no role in checking the calorie claims in restaurants, which means it's up to the states to handle the job — with the predictable patchwork results.

What Roberts’ research suggests is that calorie counts aren’t just wrong, they’re wrong in one direction. As anyone who’s ever tried to count calories knows, a difference of +18% could be devastating to a diet. Say, for example, you think you burn 2000 calories/day, like the supposed average American adult, and you’re trying to generate a ~250 calorie/day deficit through your diet. Assuming you continue to burn 2000 calories/day, that diet should make you lose about 1/2 lb per week or 26 lbs in a year. However, if you were actually eating 18% more calories than the 1750 you’ve budgeted, or 2065 calories/day, and the caloric algebra worked perfectly, you’d gain 6.8 lbs in a year instead.

Even if you’re being reductive, food is more than the sum of its parts

One factor that may work in the opposite direction: the method used to determine the caloric  content of food may systematically overestimate how much energy most people get from some foods. A quick primer on the calorie (most people who are reading this probably already know this, but since lots of people don’t): a nutritional calorie is a measure of the energy contained in food. The base unit, a gram calorie, is the amount of energy required to heat 1 gram of water 1 degree Celsius. A nutritional calorie is a kilocalorie (kcal) or “large calorie” (C), the amount of energy required to heat a 1 kg water 1 degree.

Here’s the part a lot of people don’t know: the caloric value on labels is calculated according to the “Atwater system” named after the USDA chemist William Atwater, who spent his career burning food and excrement (cue Bevis & Buthead laughter). Based on the formula Metabolizable Energy = Gross Energy in Food – Energy Lost in Secretions, Atwater came up with average energy values for each macronutrient: 9 Kcal/g for fat, 4 Kcal/g for protein, 4 Kcal/g for carbohydrates, and 7 Kcal/g for alcohol. For the purposes of nutrition labeling, even though fiber is technically a carbohydrate, it’s subtracted from the total carb weight before the calories are calculated since it’s not digested.

However, there appears to be considerable variation within macronutrients. Sucrose burns at a lower temperature than starch and isolated amino acids vary in their heat of combustion. Additionally, the Atwater system doesn’t account for differences in how macronutrients behave in when combined—for example, fiber seems to change the amount of fat and nitrogen that turn up in feces, which suggests that its effect on caloric value might not be entirely accounted for by simply subtracting fiber grams from the total carbohydrates. And, as you might expect, “variations in individuals are seen in all human studies” (Wikipedia).

The differences between estimated calories and the actual caloric value (as measured by a bomb calorimeter like the one Roberts’ team used in their study, which still might not correspond exactly to how food is turned to energy in the human digestive tract--I’m not entirely sure how calorimeters account for fiber given that fiber is combustible even though it isn’t digestible) might not be very large—but perhaps more importantly, the discrepancies probably aren’t consistent. The Atwater system is probably more accurate for some foods than others, and seems especially likely to overestimate the energy value of high-fiber foods and distort the differences between starchy and sugary foods.

That might help to explain the discrepancy seen in studies on nuts: in controlled nut-feeding trials, people eating more calories in the form of nuts don’t gain the weight that they should based on their greater energy intake. Additionally, they excrete more fat in their feces (Sabate 2003, American Journal of Clinical Nutrition). This is similar to another issue I mentioned in the introduction—not all calories are the same—but it’s not actually the same problem. Non-random variance in the reliability of caloric estimation means that even if all calories were the same, the numbers on the menus might not be accurate, i.e. the way we estimate calories might not correspond reliably to the amount of energy people actually derive from the food they eat.

So what?

Well, this means that there are (at least) two possible ways that providing consumers with “more information” in the form of calorie counts might actually lead to worse decision-making:

1) Even if people do base their decisions about what to order on the posted calorie counts, they might end up getting many more calories than they want and eating more than think they are.

2) Certain kinds of foods—including high-fiber foods and nuts, which might be “healthier” than items with lower posted calorie counts according to more holistic metrics—might have misleadingly high calorie counts based on the Atwater system. That could dissuade customers from ordering them or restaurants from offering them in favor of less “healthy” foods that may  have lower counts based on the Atwater system but actually provide more energy.

NOTE: Comments disabled due to spam. Feel free to e-mail me with responses.

Note: I try to avoid writing overly confessional, navel-gazing posts, but I’m making an exception today because I think personal narratives can be useful in attempting to understand the complexities and challenges of trying to eat “well.”  

All images in this entry from PostSecret 

When I work from home, I almost never eat out. That doesn’t mean I don’t eat prepared or processed foods—the freezer is almost always full of things from Trader Joes and the local Asian market (I know I could make tamales and pot stickers myself, and that that would probably be cheaper and perhaps better-tasting, but at least for now, other priorities win out over eating 100% cooked-from-scratch meals). But even if you don’t count TJ’s prepared foods and the occasional package of instant pho or ramen, I still eat mostly “homemade” food most of the time, even when I’m working under deadline pressure. A lot of that has to do with the fact that it’s usually quicker, easier, and cheaper to cook an egg, cut up some fruit or vegetables, or throw together a salad or sandwich than it is to go somewhere or get delivery.

Having to be at an office everyday, which I’ve been doing for the last six weeks due to a dissertation writing institute, has disrupted my eat-at-home habits. I’ve tried to pack lunches every night and keep “healthy” convenience foods like nuts and apples in my office to minimize the extent to which I end up eating out, but I haven’t been entirely successful. The availability of outside food has basically exposed me to a whole array of temptations that I don’t normally encounter, and I’ve found myself engaging in some of the patterns of impulsive or emotional eating, negative self-talk, and general anxiety about food that I thought I was mostly “over.”

Bad Day Part 1: Pizza and Self-loathing

Here’s how last Friday went:

While getting ready in the morning in the bathroom, I weigh myself for the first time in about a week. I used to weigh myself multiple times a day, taking perverse pleasure in every decrease, no matter how small, even if it was clearly due to excretion or being dehydrated from drinking too much the night before. Now I’m not nearly as obsessive, but when I see that the number is over 110—the highest it’s been in at least two years—I feel disappointed and ashamed. I tell myself the number doesn’t matter, and even if it did matter, 110.4 is a perfectly acceptable number for my height and build. And even if it wasn’t a totally acceptable number, obsessing about it wouldn’t do any good. But the best I can do is repress the emotions. I can’t un-feel them. 

In the kitchen, I look at the last container of leftover nettle soup in the refrigerator and sigh. The factors in favor of taking it are many and obvious: it is tasty, relatively healthy, easy, and will prevent me from even having to think about leaving the office to get food. There was even a handful of oyster crackers left at my office from the day before, when I had made the “right” choice and taken the soup. But I tell myself I’m “sick” of it, since I had it yesterday. I briefly contemplate grabbing one of the packages of tamales from the freezer, but then I’d have to find something to transport salsa in. Also, I don’t really have the eating implements at the office for that, and it doesn’t even sound that good in the first place. I am conscious of and unhappy about the fact that I’m making excuses. I throw some cherries in a tupperware container to eat for breakfast, feeling like that’s a reasonably healthy “trade-off” for the potentially less-healthy lunch I’m setting myself up for.

It hasn’t been a good week for dissertation writing. I keep revising instead of adding new material—or, worse, writing blog entries and playing games online. I feel lazy and ashamed, and I know that what would make me feel better is to actually do the work. But I just keep not doing it—willpower failing on multiple fronts. However, this particular morning goes pretty well. I spend an hour or so on the egg post, but then I finish revising a section of the chapter that’s been frustrating me for a while. Around noon, when I start to get hungry and distracted, I decide that the best way to keep my momentum going is to take a break and go to lunch to try to circumvent the pit of despair that I seem to slip into around 1pm.

I wander outside contemplating my options and decide to get pizza. I know this is probably among the worst of the options available to me no matter what criteria you’re using—carbs, calories, fat, pizza has it all in abundance. My justification is that I have been vaguely wanting pizza for days, so perhaps if I just have it, I will stop thinking about it and possibly compensating for not having it by “splurging” on other foods.

It tastes good, but as with most foods I have ever craved or idealized, it’s not nearly good enough to warrant either “craving” or feeling guilty about. The idea that it’s a “bad” food only makes me want it more, it doesn’t make it taste better. I probably would have gotten more pleasure from the nettle soup. I make a note of this but endeavor not to mentally castigate myself.

Perhaps because I can tell I’m on a sort of dangerous track, while I’m eating the pizza, I start thinking about a moment a few years ago that has become somewhat totemic for me as an example of my “disordered” past tendencies. I was looking at a friend’s stomach—she’s slender, but has a tiny rounded belly—and I thought something along the lines of: ugh, if my stomach ever looked like that, I’d start seriously starving myself. It was less…concrete than that because I didn’t put it into words, but it was something between that kind of thought and more general feeling of disgust and dread that seemed like it was directed outward (towards the friend) but was actually just a projected form of self-hatred. At the time, I took the comparative flatness of my stomach as evidence of my superior self-control. But I wasn’t in control—I was terrified of getting fat and ashamed of my hunger and hypercritical of my body. When I did feel beautiful back then, it was entirely dependent on feeling thin (not being thin, because it was entirely about perception, not reality) and it was a hollow, imperious sort of self-love that required other people to be fat and inferior. And most of the time, I didn’t feel beautiful at all.

Thinking about that moment and how completely insane I had to be to think this woman was fat seems to help. I say to myself: So I had pizza for lunch, so what? Eating two pieces of pizza is not some major “transgression.” It’s not going to make me fat or sick, it doesn’t make me morally weak, and it definitely does not make me less beautiful or deserving of love. Read more