Small, frequent meals vs. 3 squares a day

I have just discovered a new trove of blog topic material: the students in the nutrition class that I TA. The class's instructor requested that the TA's collect a nutrition-related question for each student, to help guide her lectures. But I think that a lot of their questions are probably the same questions that a lot of people have. But most people don't ever take a college nutrition course to learn the answers. So, I've decided to try to answer some of their questions (and maybe yours, too).

First up: Is it better to eat 3 meals per day or more frequent, smaller meals?

When I was an undergrad what feels like millenia ago, I thought I knew the answer to this. My then-boyfriend and now-husband used to think that the anonymous posters on internet bodybuilding forums were the best source of information about this kind of thing. And according to BigGuns123 and SwoleDude456, it was a no-brainer: 6 small meals per day was best for gaining muscle and losing fat. Period.

WARNING: Science-y stuff ahead. Skip this section if you are easily bored
Their argument was that after 3 hours of not eating, the body would start to break down muscle (they even used the word "catabolize" so they'd sound smarter), which ultimately leads to a decrease in metabolism. Also, the process of digestion itself was supposed to boost metabolism. I have some serious doubts about these theories. It is true that some calories are burned during digestion, but I don't see any reason to believe that the body would burn more calories digesting 300 calories 5 times than it would digesting 500 calories 3 times. The energy that is used during the breakdown of nutrients is the result of the way the chemical bonds in those nutrients are broken. So, the amount of energy needed for digestion during any given day should be dependent on the amount and type of nutrients consumed, not how often they are consumed. Second, although I am not an expert on metabolism, I am pretty confident that muscle breakdown does not occur to a great extent until fasting has been prolonged. Instead, during at least the initial 4 hours after a meal (1), the body's stores of glucose (glycogen) are used for energy along with fatty acids (from, you guessed it.. fat). Even when muscle is broken down for energy, this would only result in a net loss of muscle if protein intake throughout the day was not sufficient to replace it.

The other, more logical, argument for small frequent meals is this: if you eat regularly, you will not get a chance to feel very hungry. And when you're not ravenous, it's much easier to make smart choices about what you're going to eat and to stop eating when you are full. On the other hand, when you come to the table starving, you will eat whatever you can get your hands on and you will eat much more than your body actually needs.

Regardless of the bases for these theories, they are still just theories. What's important is what actually happens. What evidence is there to support them? As it turns out, this question does not have an easy answer. One study found that children who eat more meals are less likely to be overweight.(2) Eating just one meal per day appears to have negative effects on cholesterol and blood glucose.(3,4,5)However, there doesn't appear to be much research comparing 3 meals per day to 5 or 6 meals per day. So, it is difficult to determine whether one pattern is better than the other.

Here's my stance: Don't eat by the clock. Eat when you are hungry but not starving, and stop eating when you are comfortably full. If you feel hungry 3 times per day, then eat 3 meals. If you feel hungry 6 times per day, eat 6 meals. As always, the total calories you consume matter much more than when or how you consume them. So, eat in a way that will help you to not eat too many calories. If you are prone to snacking mindlessly all day, you may be better off limiting your eating to 3 main meals only. However, if you are more likely to stuff yourself silly at every meal, you may benefit from having smaller, more frequent meals that keep you satisfied all day so you are not driven to overeat.

References
1. Morton, The Digestive System, 2001
2. Toschke AM, Küchenhoff H, Koletzko B, von Kries R. Obes Res. Meal frequency and childhood obesity. 2005 Nov;13(11):1932-8.
3. Stote KS, Baer DJ, Spears K,et al. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults. Am J Clin Nutr. 2007 Apr;85(4):981-8.
4. Bhutani S, Varady KA. Nibbling versus feasting: which meal pattern is better for heart disease prevention? Nutr Rev. 2009 Oct;67(10):591-8.
5. Carlson O, Martin B, Stote KS, et al. Impact of reduced meal frequency without caloric restriction on glucose regulation in healthy, normal-weight middle-aged men and women. Metabolism. 2007 Dec;56(12):1729-34.

How much of your calorie budget goes to non-essentials? Discretionary calories explained

Over the last couple of weeks, the students in my discussion groups at UMass have heard (or slept through) my lecture on the food pyramid. I think that my readers might benefit from a little explanation as well. The food pyramid is pretty confusing, and there is a lot of information I could bore you with. But for now, I'm going to focus on what I think is the most important and least understood aspects of the pyramid: discretionary calories.

If you haven't seen the food pyramid in a few years, you probably haven't even heard this term. It is a new category, a substitute for the "fats, oils, and sweets" group depicted at the very top of the old food pyramid. Oils have now been recognized for their beneficial nutrients (e.g. essential fatty acids) and given a group of their own. The other fats and added sugars now comprise the "discretionary calories" (DC) group.

In a nutshell, DC are the calories left over after your nutrient needs are met. They are not unlike the money you have left after paying your bills; money you have for discretionary spending. These are the calories you can "spend" on whatever you like. The MyPyramid Plan site will tell you exactly how many of these calories you have to use each day, based on your age, BMI, gender, and activity level. For example, a 120 lb. lightly active 5'4" 25 year old female has a daily allowance of 195 discretionary calories.

One could use this allowance on approximately 6 oreo cookies. This may sound like a generous amount of junk food to be able to eat daily. But, what many people don't realize is that these nutrition-less calories are not only found in the obvious places-- cakes, cookies, fried foods, and the like-- but also lurking in less conspicuous staples of the American diet. For example, a cup of 2% milk has 41 DC, a single slice of cheese 83 DC, and a small hamburger patty has 74. Even seemingly harmless foods like low-fat yogurt (97 DC), granola bars (59 DC), and fruit sorbet (82 DC) can quickly whittle away your discretionary calorie allotment.

The important thing to remember about these calories is that they provide no valuable nutrients. They are truly "empty calories." All they do is give you more energy which, if not needed, will be stored as excess fat. The flip side of this is that foods high in DC tend to displace more nutritious foods. So, not only are you getting more calories than you need, but you may also not be getting enough nutrients because you are foregoing healthful things like fruits and vegetables in favor of the junky stuff.

If you want to know how much of your daily calorie budget you're spending on foods that don't do anything good for you, go to the MyPyramid site to find out your DC limit, and then check out MyFood-a-pedia.gov. It has a searchable database of foods with complete information about the food groups they belong to and their exact number of discretionary calories (called "Extras").

While I am at it, a final word on the food pyramid: I don't think it is anywhere near the best nutritional guidance we can come up with. For an alternative view, you may want to consult Walter Willett's Food Pyramid. This one is actually based on science, not input from agricultural lobbyists.

Eat this veggie!

Over the weekend, I made one of my favorite vegetables to accompany my lunch; one that I think few others ever eat. Fennel. As I took my first bite, taking in the taste of the lightly salted, crunchy/soft, toasted pieces of the licorice-scented plant, I thought "why don't more people eat this?" I think everyone should know about this tasty and healthful food, so here I am, telling you about it.
This is what fennel looks like when you buy it in the store. Sometimes it's labeled "anise."


To prepare it, cut off the green stems and slice the bulb like you would an onion. I cut the bulb in half and then slice each half. You can eat it raw on a salad or, as I prefer it, roasted in the oven. Actually, I broil it technically. Grilling is another option. Once it's sliced, I lay the slices on a baking pan sprayed with oil spray (like PAM), spray another coat of oil on top of the slices, and season with salt & pepper. Then, I put the pan under the broiler until the fennel is browned, flip the slices once and let them cook until lightly browned on the other side.

I love fennel just by itself, but it's also very good with carrots, potatoes, other root vegetables, and fish. It has a unique flavor unparalleled by other vegetables and plenty of nutrition, too. Fennel is low in calories and high in vitamin C and fiber. So next time you're in the mood for something a little different, give fennel a try!

What you're not worrying about, but should be

Unless you have diabetes, you probably don't think about your blood glucose levels very often. If you're young, you proabably never think about it. If you're older, you might think about it once a year when you get your annual physical and get your fasting glucose levels checked. Physicians don't make a big deal out of blood sugar, so you probably assume it's no big deal. Sometimes a nutritionist might say something about certain foods being good because they "stabilize blood sugar," but the benefits of that stabilization still probab ly seem a little vague to you. Perhaps you've heard that if you prevent your blood sugar from spiking, you'll also prevent the mood swings, fatigue, and ravenous hunger that can result when you "crash" back down from a glucose peak. If you are particularly well-read you may also have heard something about insulin promoting fat storage when blood sugar is high.

While the term "fat storage" can incite fear well enough on its own, there are even more severe consequences to blood sugar levels that are higher than they should be- even if they are not, by clinical definition, abnormal.

First, a little background information, so we're all on the same page. Below are the fasting blood glucose (FBG) and 2-hour oral glucost tolerance test (OGTT) cut-offs for diabetes mellitus and impaired glucose tolerance (AKA pre-diabetes).

Normal: FBG < or =" 99;">OGTT < or =" 139

Impaired Glucose Tolerance: FBG 100-125; OGTT 140-199

Diabetes: FBG 126 and above; OGTT 200 and above

The problem with these cut-offs is that they are somewhat arbitrary. They seem to give the impression that any blood glucose value in the normal range is, well, normal, and that pre-diabetic levels are only a warning of possible future problems if left uncontrolled. What your physician won't tell you is that even within the normal range, lower is better, and that having impaired glucose tolerance can increase your risk for cardiovascular diseases and death, even if you never become diabetic.

The truth is, even a glucose level of 140 can cause damage to blood vessels and to the cells of the pancreas that produce insulin. Blood vessel damage can lead to artery plaques, which can ultimately cause heart attacks. A glucose level of 140 is not what any doctor would call "high," and yet it appears to be an important threshold. Just to be clear, glucose in the blood is dangerous no matter when it happens. So, if your glucose is high after a meal, but normal when you are fasting, you are still going to be at higher risk than someone who has normal glucose levels all the time. In fact, risk of cardiovascular disease increases with OGTT values as low as 80!! Lower really is (nearly) always better in this case. The problem is, most people have no idea what their blood sugar is after a meal. The average person only receives fasting blood glucose tests regularly, not OGTTs. Unfortunately, FBG will start to rise only after post-meal glucose has been elevated for quite some time. This means that by the time a person has a high FBG, a lot of damage has already been done.

So what are you supposed to about this?? Here are my recommendations:

1. If you have any of the following risk factors, talk to your doctor about whether you should have an OGTT: overweight with mostly belly fat, obese, polycystic ovary syndrome (PCOS), first-degree relative with type 2 diabetes (parent, sibling)

2. Be on the look out for free glucose screenings in your area and plan to go about an 1- 1.5 hours after a meal to catch your peak level.

3. Regardless of what your glucose levels are after eating, virtually everyone could benefit from reducing that level. So, think about making dietary choices that will maintain a stable blood sugar.

Some suggestions:

Reduce your portions of starches

Choose whole grains over refined grains

Increase your portion of vegetables

Choose whole fresh fruits over fruit juices or canned fruits

Eat lean protein and healthy fats (olive oil, canola oil, etc.) with starchy foods

Swap out artificial sweeteners (like Splenda) for sugar wherever you can

Switch from regular to diet soda, or no soda

Snack on nuts and fruit rather than high-carb granola bars or candy

Start your day with eggs and/or a high-fiber cereal

Also, physical activity can help your body to use the glucose in your blood, so if you must have dessert, go for a walk afterwards!

References

Ceriello A. Impaired glucose tolerance and cardiovascular disease: the potential role of post-prandial hyperglycemia. Am Heart J. 2004

MedScape article

Peter R, Okoseime OE, Rees A, Owens DR. Postprandial glucose- a potential therapeutic target to reduce cardiovascular mortality. Curr Vasc Pharmacol. 2009

I heart Chobani

If you haven't jumped on the Greek yogurt bandwagon yet, you need to get on it. And the best brand (in my not-so-humble opinion) is Chobani. What makes Greek yogurt so special? It's super thick and creamy, which makes it ideal as a substitute for sour cream or as a decadent sweet treat. Another reason why I love it is that it is nutritionally superior to other yogurts. It is much higher in protein than other yogurts, which means more nutrient bang for your calorie buck, and probably a lower glycemic index as well (though I can't be sure of that; I don't think it's been tested).

For example, 6 oz. dannon nonfat plain yogurt has 80 calories, 12g sugar, and 8g protein. This is pretty good!

But Greek yogurt has even better stats: a few more calories (100), but only 7g of sugar and a whopping 18 grams of protein!!

For people who aren't into plain yogurt, Chobani makes some great flavored yogurts, too. I had the pleasure of trying two of their new flavors: 2% strawberry-banana and 0% raspberry. They were both delicious! I hadn't ever tried the 2% yogurt before, but that could be a special indulgence because it was SO creamy and rich. Both of the yogurts had the fruit on the bottom that reminded me of the yogurt I ate as a child, before I cared about calories.

But even the sweetened yogurts are well within a reasonable range of calories for a snack. The flavored 0% yogurts have 140-150 calories, 20g sugar, and still pack 14-16g of protein. The 2% pineapple yogurt has 160 calories, 21g sugar, and 13g of protein.

In comparison, Yoplait light yogurt has fewer calories (100) but about the same number of carbs (19) and only about a third of the protein (5g). Original Yoplait's nutritional value is abysmal with 170 calories, 27g sugar and still only 5g of protein! You might save a couple of calories eating the light version, but the Chobani yogurt will be more filling (so you'll be apt to eat less later on) and will probably have a smaller impact on your blood sugar, which is more important than you know. I will be dedicating a post to this topic in the near future, so keep an eye out for it.

And if the superior nutrient profile isn't enough to convince you to switch to Greek yogurt, it just tastes a whole lot better! I know Yoplait has this "thick and creamy" line out, but that just tastes like yogurt mixed with jello, and essentially, that is what it is. The yogurt is thickened artificially with gelatin. Chobani, on the other hand, is naturally thick and creamy, and way better than anything else out there.

My only complaint about Chobani is that they don't have any truly "light" yogurts, sweetened with sugar substitutes. Although the flavored yogurts aren't very high in calories, I just can't bring myself to eat that much added sugar. I don't care if it's "natural" sugar, it's still sugar. As a result, as good as the new flavors are, I am going to stick with what I've been eating almost daily these days: Chobani nonfat plain yogurt, to which I add splenda and thawed, frozen blueberries. I don't think anything they could make could trump this combination in taste, but it would be nice to be able to have a no-sugar-added but still sweet version of this to take on the go when it's not so convenient to mix it myself.

Chobani, if you're listening, what are you waiting for?!! So many weight-conscious yogurt-eaters out there are currently gobbling up that watery, chalky tasting excuse for a "light" yogurt that's being pushed by that OTHER yogurt company (you know which one I'm talking about) simply because it's the lowest calorie option available. This is a travesty! With a few simple adjustments, Chobani could make the best-tasting AND most nutritious low-calorie yogurt on the market. I get that they're committed to "all-natural" ingredients and don't want to use artificial sweeteners, but even that's not an excuse anymore, what with Truvia and other erythritol-containing natural non-nutritive sweeteners now widely available. Time to get on the ball, people!

Check out Chobani's website
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On mammograms and politics

When I started this blog, I wanted to keep politics out of it. Mostly because talking about politics always leads to arguments, and as much as I can enjoy a good debate, I usually end up feeling stressed out and frustrated. The people who argue about politics feel very strongly about their convictions and typically seek out information that confirms their opinion while dismissing anything that supports the contrary view. It's called confirmation bias. Because of this phenomenon, I know that I will not be able to convince anyone on the opposing side to change their minds any more than they could convince me to change mine. So I usually prefer to not talk about politics unless provoked. But I am so struck by some recent developments in public opinion on a couple of health care issues that I feel the need to break my own rule. I might not sway people on the other side, but maybe I can help push some people who are on the fence closer toward the right side: my side. Okay, just kidding about that.. sort of.

If you haven't heard about the new recommendations about mammography screenings that have been released by a panel of experts to advise the Department of Health and Human Services, you must be living under a rock. In a nutshell: a review of evidence has led the panel to conclude that routine mammography screenings are not necessary for women under 50.

This recommendation has not surprisingly been met with downright furor from the American public, and especially women. Young breast cancer survivors are standing up saying, "A mammogram saved my life" and critics are calling it a step towards "rationed health care." I can understand these points of view.. to a point. Being a believer in evidence-based life (as the title of my blog suggests), I support the new recommendations, and I'll tell you why in a minute.

First, I have a question for those who think the panel is wrong. It occurred to me after reading a letter to the editor in my local newspaper this morning. In it, the writer says "Shame on this panel. We want to save lives no matter what the cost." My question for this writer and others like her is: Do you also support saving the lives of Americans who are currently uninsured, no matter what the cost? Or is it only the lives of people like you (the "us" in the world) that you want to save, while the rest ("them")are left to get sick and die?

At this time in this country, I am hearing two arguments that, to me, seem contradictory. On one hand, it is morally imperative that we perform 19,000 unnecessary mammograms in order to save one woman's life (NY Times) "no matter what the cost"; and on the other hand, health care reform designed to expand access to health insurance is simply too expensive. I would hope that these arguments are coming from two discrete groups of people, but I suspect there is some overlap; some people who are making both arguments at the same time. This doesn't make sense to me. The only explanation I can think of is that some people will justify any expense to save the lives of the people they can relate to: middle-class or wealthy Americans who already have health insurance, but are simply unwilling to pay to save the lives of those who are below them on the socio-economic totem pole: the poor and uninsured. Now that, to me, is morally reprehensible.

I could go on about that, but I have other things to do with my day so I will leave it at that. Now, to explain why I agree with the mammography recommendation:

1. Although there is the rare virulent cancer that is detected by early mammography screening, there are also other, slowly-growing and innocuous cancers that are detected and treated unnecessarily by risky procedures like surgery, chemotherapy, etc.

2. The recommendation only advises against routine screening, not screening in general. So, for women who are at high risk and would receive the most benefit from early screening, that will always be an option. Even if insurers were to use this recommendation to change their reimbursement policies (which they are NOT doing anyway, so relax), it would only mean that a mammogram would have to be prescribed by a physician after assessing an individual patient's risk, similar to the way that blood tests are ordered and covered by insurers now. My insurance company doesn't cover "routine" blood tests (i.e. blood tests for no good reason), but as long as my physician signs off on it because she feels it is necessary for diagnosis, it is all paid for. Women are not being told not to get screened, they are only being told to make the decision with their physicians on an individual basis rather than automatically being screened every year. I don't see what is so horrible about this.

3. If routine screening for women in their 40's is worth the cost because it saves a handful of lives, then why wouldn't we expand the screening to women in their 30's? Or 20's even? There are women who develop breast cancer and die from it in those age groups as well, so if we are unable to accept any level of risk, shouldn't all women who could possibly develop breast cancer be screened? And for that matter, although it is rare, breast cancer can occur in men, so should all men be receiving regular mammograms, too?

This "save every life at any cost" mentality, though understandable, could lead to a slippery slope of more and more unnecessary screenings for more people, and subsequently higher health care costs. Furthermore, it may backfire by leading to excess disease and deaths in other segments of the population. The uniquely American unwillingness to look at disease from a public health perspective rather than an individual perspective is one of the reasons that the United States spends so much more on health care than other countries, without receiving the dividends of better health outcomes. Although it is difficult, sometimes it is necessary to think with our heads rather than our hearts. The cost of excessive procedures will be paid not only in dollars and cents, but in lives as well. It might save the lives of a few, but those savings will ultimately be paid by those for whom the resulting higher costs of health care become prohibitive. If the cost of health care is increased, access will be decreased, which will lead to greater morbidity and mortality for those who don't have it.

And just think about this: there are already women who can't afford to get mammograms at any age and regardless of their risk because they don't have health insurance. Maybe our first concern should be to get them covered. But then the question is, are they worth saving "at any cost"?

Deceptive Advertising: Nutella

There's a new commercial I keep seeing for Nutella that is really pissing me off (View it at Nutella's website here). Now, I have to admit, I love me some Nutella. I might not eat it very often, but it's seriously good stuff. But my affection for the product does not mitigate my disgust with the company's marketing practices.

The commercial, for those of you who can't be bothered to click the link, features a mom talking about all of the reasons why she likes to give her kids Nutella. She says Nutella is "a delicious hazelnut spread I use to get my kids to eat healthy foods. I spread a little on all kinds of healthy things, like multigrain toast. Every jar has wholesome, quality ingredients like hazelnuts, skim milk, and a hint of delicious cocoa. And Nutella has no artificial colors or preservatives." Sounds pretty good, right? Let's look at each of these claims separately shall we?

1. Nutella can get kids to eat healthy foods. Notice, she doesn't say that Nutella IS a healthy food. That's your first clue. If the best thing that can be said about the product is that it helps kids eat OTHER foods that are healthy, chances are the product itself is not.

2. It contains wholesome ingredients. What the hell does that even mean??? Does anyone know? Let me give you a tip: "wholesome" is the word food manufacturers use to describe foods that have no nutritional benefits worth mentioning. The dictionary definition of wholesome is "promoting health," but the professor of my food science class defined it differently. He said "wholesome" refers to foods that contain everything you would expect them to contain and nothing else. In other words, they have not been contaminated by substances you wouldn't want in your food (like chemicals, insects, etc.) "Wholesome" CAN refer to healthy foods such as fruits and vegetables, but it can just as easily be used to describe butter, bacon, and french fries. When you hear this word, just ignore it.

3. Nutella contains hazelnuts, skim milk, and a "touch" of cocoa. Maybe so. They're probably not making this up, but let's look at what else is in it. According to the label, the first ingredient is not hazelnuts, skim milk, or cocoa. It's sugar; 21 grams of it per serving to be exact. Why don't they mention that in the commercial? Oh and there's also some modified palm oil, a saturated fat (i.e. artery-clogging fat). And the skim milk? It's down at the bottom of the list. You can't tell how much skim milk you'd actually get in one serving, but judging by the 4% daily value of calcium each serving contains, you can bet it's not much. An 8 ounce glass of skim milk provides 30% of the daily value for calcium, so if you do the math, that's about 2 tablespoons, or .13 servings of dairy.

4. Nutella has no artificial colors or preservatives. My short answer to this is: so what?! There is no convincing evidence that either of these things has any negative effect on health. But there is plenty of evidence that sugar, saturated fat, and excess calories contribute to all kinds of health problems.

This kind of advertising (and I've seen it done many many times before) makes me think that we really need more regulation of food advertising. If a product has an overall poor nutritional profile and is likely to promote disease rather than health, a company should not be allowed to suggest that it is nutritious. It is deceptive and unethical. These companies are exploiting the public's lack of nutrition knowledge and profiting while their customers suffer the consequences.