After enjoying myself while on vacation in Chicago, I decided to do penance by reading more of the 2010 Dietary Guidelines. (Our house, meanwhile, imposed its own penance by developing a plumbing problem that caused the toilets to back up into the downstairs bathtub. I’m not sure which was more nauseating: scooping sewage from the tub, or reading the Dietary Guidelines.)
The 86-page section I just finished is titled “Energy Balance,” but could’ve been titled “Let’s Put Our Heads Together and Save The Reputation of The Carbohydrate” or perhaps “Nobody Who Blames Carbohydrates Gets Out of Here Alive.”
In a nutshell, this is what the committee concluded:
- We’re fat because we consume too many calories and don’t move around enough, period, end of story, so would everyone please shut up about macronutrient balances and just go on a low-calorie diet for Pete’s sake, and then maybe go jogging.
- We consume too many calories because we eat too much fat … uh, and sugar too.
- We eat too much fat (uh, and sugar too) because there are too many fast-food establishments and not enough grocery stores and produce markets.
For the two or three people living in civilized society who are unfamiliar with the theory that consuming more calories than you burn will make you fat, the committee generously took the phrase “consuming more calories than you burn will make you fat” and translated it into impressive-sounding Engfish:
Energy balance refers to the balance between calories consumed through eating and drinking and those calories expended through physical activity and metabolic processes. Energy consumed must equal energy expended for a person to remain at the same body weight. Overweight and obesity will result from excess calorie intake and/or inadequate physical activity. Weight loss will occur when a calorie deficit exists, which can be achieved by eating less, being more physically active, or a combination of the two.
So there you have it: the key to losing weight is to base your diet on a theory that has less than a 2% success rate. But hey, if you’re one of the 98% who tried to lose weight and failed, don’t feel bad. It’s not your fault, really. As the committee explains:
Examining shifts in the food environment over the past 40 years is helpful in understanding why Americans have difficulty meeting the U.S. Dietary Guidelines.
As someone with working tastebuds, I always assumed most people had difficulty meeting the U.S. Dietary Guidelines because they don’t like bland, low-fat, low-salt, tasteless grain-based foods. Turns out I just didn’t have the intellectual capacity to fully grasp the many complexities involved. You can read about those complexities in the official report if you want to give yourself a serious headache, but just to give you an idea, I copied the helpful graphic provided in the report:
Wow … and to think some people still believe in the concept of free will. Clearly, this amazingly complex set of environmental influences can only be solved by an equally complex set of government initiatives. The committee offers just a hint of things to come. (Those “things,” since this is a government committee, would be regulations.)
In order to reduce the obesity epidemic, actions must be taken to improve the food environment. Policy (local, state, and national) and private-sector efforts must be made to increase the availability of nutrient-dense foods for all Americans, especially for low-income Americans, through greater access to grocery stores, produce trucks, and farmers’ markets, and greater financial incentives to purchase and prepare healthy foods. The restaurant and food industries are encouraged to offer foods in appropriate portion sizes that are low in calories, added sugars, and solid fat. Local zoning policies should be considered to reduce fast food restaurant placement near schools.
Yup, we need those regulations and financial incentives because poor people don’t have enough access to grocery stores and have too much access to fast food. Here’s how the committee figured it out:
The presence of supermarkets in local neighborhoods and other sources of vegetables and fruits are associated with lower body mass index, especially for low-income Americans, while lack of supermarkets and long distances to supermarkets are associated with higher body mass index. Finally, limited but consistent evidence suggests that increased geographic density of fast food restaurants and convenience stores is also related to increased body mass index.
An economist would say that a lack of supermarkets is associated with a lack of community support for supermarkets, while a high concentration of fast-food restaurants is associated with strong community support for fast food. But apparently the committee has figured out that supermarkets are avoiding low-income areas because they just don’t want the extra business. So now we need to bribe them … or the people in the community … or … well, dangit, I don’t know, but SOMEBODY needs to be bribed, or that graphic explaining all the complexities will look exactly the same when the 2015 committee meets.
My graphic of the problem would look something like this:
The committee, empanelled by a government that spends billions of dollars subsidizing grains (and millions more subsidizing research conducted by anti-fat hysterics), heartily disagrees. Okay, it’s impossible to express anything “heartily” in Engfish, but you get the idea. They assure us that fat is a major culprit behind the rise in obesity.
To make the document impressively large, they included long sections discussing food production figures, adolescent screen time, who eats breakfast and who doesn’t, maternal weight during pregnancy, calorie counts of various beverages, caloric expenditure for various forms of exercise, methodologies for gathering data on all the above, etc. I’ll skip those because they’re more boring than C-SPAN and don’t contain anything useful.
The real story for me was how they managed to blame fat for making us fatter while exonerating carbohydrates. To accomplish this, all they had to do was cherry-pick, ignore, or explain away the actual evidence. Here’s a sample from the section on childhood obesity:
The relationship of dietary fat to adiposity in children has been studied more extensively than for other macronutrients, primarily because of its high energy density and palatability, both qualities likely to promote passive overconsumption of energy if not regulated (Parsons, 1999). In addition, studies suggest that fat intake induces less potent satiety signals and less compensation with respect to subsequent energy intake, compared with dietary protein or carbohydrate (Doucet, 1997; Bray, 2004), and that fat oxidation is not as highly regulated as carbohydrate utilization.
Okay, I have to interrupt the committee at this point. Are they actually telling us that fat doesn’t provide satiety, but carbohydrates do?! Does anyone makes jokes about how an hour after eating at a steak house, you’re hungry again? Sometimes when I have sausage and eggs for breakfast, I forget to eat lunch. That never, ever happened when I ate Grape-Nuts. Even some of the most strident anti-Atkins hysterics admit people lose weight, but then explain that it’s only because all that fat is satisfying, so people eat less. They call it a “low-calorie diet in disguise” — usually just before warning that you’ll die of a heart attack.
But back to the committee:
In metabolic studies of children, meal induced thermogenesis increased more after a high-carbohydrate meal than after a high-fat meal; and although fat oxidation increased after the high fat meal, postprandial fat storage was greater after the high fat meal compared with the high carbohydrate meal (Maffeis, 2001).
Ah, I see. So it’s the fat that’s making our youngsters fat, while carbohydrates keep them lean. I guess if somebody created a list of what kids actually eat, fatty foods would be at the top.
Oh, wait … somebody did create that list. In fact, the committee created the list. Here, as published in their own report, are the top 10 sources of calories for males between the ages of two and 18:
2. Grain-based desserts
3. Soda/energy/sports drinks
4. Chicken and chicken mixed dishes
5. Yeast breads
6. Reduced fat milk
7. Dairy desserts
8. Pasta and pasta dishes
9. Ready-to-eat cereals
Here’s the same list for females between two and 18:
1. Grain-based desserts
2. Yeast breads
3. Pasta and pasta dishes
5. Chicken and chicken mixed dishes
6. Soda/energy/sports drinks
7. Reduced fat milk
8. Potato/corn/other chips
9. Dairy desserts
10. Mexican mixed dishes.
Call me crazy, but that looks like a list dominated by carbohydrate-rich foods. I wonder why the heck all that highly regulated carbohydrate utilization isn’t producing satiety and massive thermogenesis in our kids and keeping them thin. By the way, whole milk, beef and cheese are pretty far down on the list for both genders. Pork products were at 17 for both genders, and eggs didn’t make the top 25 in either group.
In another major section on Fat and Cholesterol (which I’ll get to in another post), the committee lists our average fat intake over the decades. Check out these figures:
Total fat grams per day – 84.6
Fat percent of total calories – 40
Total fat grams per day – 71.4
Fat percent of total calories – 32.8
Total fat grams per day – 81.9
Fat percent of total calories – 33.6
Anyone care to read those figures and then explain to me how it’s too much fat that sparked a rise in obesity? Were we fatter in 1977, when we ate more of the stuff? Amazing … these people can see the evidence right in front of their academic faces, then draw conclusions that have nothing to do with it.
Here’s an another example of explaining away results they don’t like:
One longitudinal study found no association between dietary energy density and adiposity among children who were followed annually from age 2 to 18 years (Alexy, 2005). Participants in this cohort were classified by dietary pattern into clusters based on percent energy from fat, with dietary energy density lowest at 3.7 (0.4) in the low fat cluster; 4.0 (0.4) in the medium fat intake; and highest at 4.1 (0.4) in the high fat cluster. Mean BMI during the study period differed significantly, with the highest BMI in the low fat, low dietary energy density cluster, a result the investigators suggest may have reflected under-reporting of energy intake among overweight participants, difficulty in detecting minor over-consumption of energy, and lack of power due to small sample size.
Get that? In this study, kids who ate the diet lowest in fat had the highest BMI … but by gosh, we can dismiss this one because the investigators suggested the fat kids (and only the fat kids) didn’t report their intake accurately. How convenient. I’ll bet you dollars to donuts that if the low-fat group had the lowest BMI, the investigators wouldn’t have felt any need to pooh-pooh their own results.
The examples of explaining away or completely ignoring the evidence get even worse. If you can stay awake long enough, read this paragraph carefully:
Three of the four RCTs found no association between percent energy from dietary fat and adiposity. The STRIP clinical trial, which tested the effects of a fat-modified diet from 7 months of age (Hakanen, 2006), reported less obesity among intervention girls compared with control girls at age 10 years, but no differences for boys; while at age 14 years, Niinikoski et al. (2007) found no difference in obesity between treatment groups, for either males or females. Caballero et al. (2003) reported no change in percent body fat in a 3-year school-based nutrition and physical activity intervention among 1,704 Native American children, who were age 7 years at baseline. Results showed that percent body fat and BMI did not differ by treatment group at study end. However, children in the intervention group reported lower total energy intake (1,892 vs. 2,157 kcal/d) and percent energy from total fat (31.1% vs. 33.6%) compared with the control group, and percent energy from fat was lower in the intervention school lunches compared to the control schools (28.2% vs. 32.0%).
So in several trials, kids who were put on a low-fat diet didn’t end up any leaner than the kids in the control groups. And in the last study cited, the kids on a low-fat diet consumed less fat and fewer calories but STILL didn’t end up any leaner. Now, if you have a functioning brain, you’d probably look at that as evidence that low-fat diets aren’t the key to making kids leaner. But unfortunately, having a functioning brain would also disqualify you from serving on a government nutrition committee — as evidenced by their conclusion:
In summary, the combination of evidence from methodologically strong studies in the NEL and ADA reviews supports a conclusion that dietary fat and adiposity in children are positively associated.
Yes, you read that correctly. No, it doesn’t make any sense. I’m starting to wonder if they made the document long and boring in hopes that no one would bother to analyze it.
Since this committee was no doubt given the task of justifying the Food Pyramid, they did their best to dissuade people from attempting to lose weight by giving up grains and other subsidized carbohydrates:
There is strong and consistent evidence that when calorie intake is controlled, macronutrient proportion of the diet is not related to losing weight. A moderate body of evidence provides no data to suggest that any one macronutrient is more effective than any other for avoiding weight regain in weight reduced persons. A moderate body of evidence demonstrates that diets with less than 45 percent of calories as carbohydrates are not more successful for long-term weight loss (12 months). There is also some evidence that they may be less safe.
Hmmm, I wonder which evidence convinced them low-carbohydrate diets may be less safe? It certainly wasn’t the study published in the American Journal of Clinical Nutrition that concluded women who ate a high-fat diet showed less progression of heart disease than women who ate a high-carb diet. Or the study published in the Journal of the American Medical Association that concluded that women who followed the Atkins diet lost the most weight and had the best metabolic markers. Or the study published in the American Journal of Clinical Nutrition that found zero association between saturated fat and heart disease or stroke. Or about a dozen more I could name.
Well, let’s just set aside the safety issue and look at their evidence on weight loss:
Twenty studies found no difference in weight loss between diets differing in macronutrient proportion. (Arvidsson, 2004; Avenell, 2004; Benassi-Evans, 2009; Capel, 2008; de Luis, 2009; Frisch, 2009; Gordon, 2008; Jenkins, 2009; Johnston, 2006; Leidy, 2007; Lim, 2009; Lopez-Fontana, 2009; McLaughlin, 2006; Miller, 2009; Noakes, 2006; Sacks, 2009; Tay, 2008; Viguerie, 2005; Wal, 2007; White, 2007).
Thirteen studies found that lower carbohydrate diets reduced weight significantly more than low-fat or higher-carbohydrate diets (Buscemi, 2009; Halyburton, 2007; Hession, 2009; Johnstone, 2008; Keogh, 2008; Krieger, 2006; Mahon, 2007; McAuley, 2005; Nickols-Richardson, 2005; Nordmann, 2006; Rankin, 2007; Shai, 2008; Volek, 2009).
Isn’t that interesting? First they tell us it’s fat making us fat. Then they tell us 20 studies showed the macronutrient content makes no difference in weight loss. And finally they tell us 13 studies showed people lost more weight on low-carbohydrate diets. Notice they didn’t cite any studies showing that low-fat diets — the type they recommend — produce more weight loss.
Interestingly, in a document full of research citations, I didn’t find a single reference to the Stanford study conducted by Dr. Chris Gardner — a vegetarian who admitted he was a bit dismayed when his own results showed that people on the Atkins diet lost the most weight and had the biggest improvements in health markers. Somehow, a committee that brags about its efforts to review all the relevant evidence managed to skip that one.
If 20 studies showed no difference, while 13 other studies showed greater weight loss for people restricting carbohydrates, then the obvious conclusion is that low-carb diets are more effective for quite a few people. (Heck, let’s make it 14. I’ll throw in the Stanford study, even if they didn’t.) But you can read the report forwards, backwards, and sideways, and you’ll never find that possibility even mentioned.
And if you were to dig into the 20 studies that showed no difference, I promise you’d find many of them used a loosey-goosey definition of “low carbohydrate.” The committee, for example, defines it as less than 45% of calories. That’s a common trick employed by researchers who set out to prove low-carb diets don’t work. (See this post for an example.)
Anyone who reads the Atkins books, the Protein Power books, or any other book on low-carb diets knows you’re supposed to kick-start the fat-burning process by reducing your carbohydrate intake to 20-40 grams per day for a couple of weeks, then gradually raise it to perhaps 60-100 grams per day, depending on your reaction to carbohydrates. At 1800 calories per day, a diet that’s 40% carbohydrates would work out to 180 grams. Even 30% percent carbohydrates would work out to 135 grams.
Most of the people I know who lost weight by restricting carbohydrates limited their carb intake to somewhere between 5% and 20% of total calories. So the “low carb” diet in many of these studies wasn’t even close to what Dr. Atkins or Drs. Eades and Eades advised … it’s just lower in carbs than what the federal government recommends.
Just to make sure we didn’t miss the point, the committee tossed in this paragraph near the end:
The macronutrient distribution of a person’s diet is not the driving force behind the obesity, rather it is the overly large amount of total calories eaten coupled with very low physical activity. There is no optimal proportion of dietary fat, carbohydrate, and protein to maintain a healthy body weight, to lose weight, or to avoid weight regain after weight loss. It is the total amount of calories eaten that is essential. While weight can be reduced with diets where the macronutrient proportions vary widely, the crucial issue is not the macronutrient proportion but rather the compliance with a reduced-calorie intake.
We’re just plain eating too much, you see. As Gary Taubes noted in Good Calories, Bad Calories, saying fat people are fat because they eat too much is about as illuminating as saying alcoholics are alcoholics because they drink too much. It doesn’t begin to explain why. It doesn’t even ask the question.
We eat too much because we’re too hungry. And we’re too hungry because the federal government decided to tell us how to eat and helped turn us into a nation of carbohydrate addicts. Isn’t it comforting to know they’re coming to save the day?