If I limit saturated fats, do I need to worry about total fat?

Q.  I understand that fat should be limited in one's diet. However, I also understand that it's the saturated fats that are worst. Would it make sense to limit the saturated fats and not the total fat in the foods one eats?

A. Let's start with the "official" answer and then we'll dig a bit deeper.

The National Academy of Sciences (which sets the government's official dietary recommendations) suggests that you limit your saturated fat intake to 10% or less of your total calories and avoid trans fats entirely.  In addition, they also recommend limiting total fat to no more than 35% of all your calories.   

One reason to limit your consumption of fat is that eating a lot of high-fat foods--even when they contain "healthy" fats--can seduce you into eating more calories than you otherwise would, or should.  Fats are very calorie-dense but not particularly satiating, meaning that you can consume a whole heck of a lot of fat calories before you start to feel full.

But if you are eating the appropriate number of calories and otherwise getting all the nutrients you need, I think its possible to push the fat ratio a little higher and still have a very healthy diet.  A Mediterranean diet, for example, emphasizing fruits, vegetables, whole grains, fish, nuts, and olive oil has been shown to be extremely healthful, and may contain up to 50% of the calories from fats (mostly monounsaturated).

Now let's muddy the water even further:  Many readers of this blog would argue that there is no need to limit saturated fats because it's carbs that cause heart disease, not saturated fat. See, for example, the lively conversation going on on this post about eggs.   

I think the important principle here is you can't draw conclusions about the effects of individual dietary components, such as saturated fat, without taking into consideration the composition of the rest of the diet.

There is certainly a lot of evidence suggesting that a diet high in saturated fats can be quite healthy, providing that it is also very low in refined carbohydrates. On the other hand, a diet high in both saturated fats and refined carbohydrates is a pretty bad idea.  So, how much (and what kind of) fat your body will thrive on depends on your genetics and, even more importantly, how the rest of your diet looks.

One last twist: we've talked about saturated fats, trans fats, and monounsaturated fat, but haven't yet mentioned polyunsaturated fats (PUFAs).  You need a small amount of PUFAs in your diet because they supply essential fatty acids that you cannot get from any other source. These include the notorious omega-3 and omega-6 fats. 

It's very important to strike a balance between omega-6 and omega-3 fats. Most of us get a whole lot of omega-6 PUFAs (which are found in cereal grains, seeds, and vegetable oils) and not enough omega-3 PUFAs (which are found in fish, hemp, chia, and flaxseeds).   The resulting imbalance can lead to chronic inflammation, which increases your risk of many diseases. 

You read an awful lot about the importance of adding more omega-3 to your diet.  But there's another option that I don't see talked about much: reduce your consumption of omega 6!  When the two are in balance, you don't really need very much of either; a couple of grams per day is sufficient.  If you analyze your diet using ND's tracking tools, you'll see total omega-6 and omega-3 amounts (along with totals for saturated, trans, and monounsaturated fats) listed as part of the analysis report.

Osteoporosis Awareness: new guidelines focus on men at risk

Although women are routinely screened for osteoporosis starting at around age 50, physicians typically do not worry about the bone health of their male patients. They should.

One in six men will have osteoporosis by age 65 and the vast majority will go undiagnosed and, therefore, untreated--until their bones are so brittle that they may break during everyday activites. By that time, it's usually too late to get much benefit from bone-preserving therapies that can slow bone loss and prevent injury and disability.  Consider this: men who break a hip are twice as likely to die within one year.

New guidelines released this month by the American College of Physicians call for osteoporosis screening for men, beginning at age 65 or earlier, if men are at increased risk. Things that increase risk include:

• taking anti-androgenic drugs (used to treat prostate cancer)
• low body weight
• physical inactivity
• smoking
• low calcium and vitamin D status

May is Osteoporosis Awareness and Prevention Month: Are you doing enough to protect yourself from osteoporosis?

How does cooking affect vitamin K content?

Q. For foods that act as natural blood thinners (such as broccoli, cabbage, etc.), does it make a difference whether the foods are eaten raw or cooked? My mom, who takes prescription blood thinners, has been told that she should avoid all these foods. But these foods are also good for you and I would like to be able to find a balance. It seems to me that you would need to consume a great deal of vitamin K in order for it to produce a negative effect together with the Coumadin.

A. First, a clarification on why people taking blood-thinners are sometimes advised to avoid foods that are high in vitamin K. Vitamin K does not act as a natural blood-thinner; quite the opposite. Vitamin K regulates clotting action and can interfere with blood-thinning medication.

But you are quite right to note that these foods are also very good for you and, in fact, it is not necessary to eliminate them from the diet when taking blood-thinning medication.  It is important, however, to keep your intake of vitamin K relatively steady from day to day so that your doctor can calibrate your dosage appropriately. Please refer to this post for a more complete discussion of this issue.

To your question about how cooking affects vitamin K levels: The amount of vitamin K is not greatly affected by cooking.  Nonetheless, most vegetables are listed in our database in both their raw and cooked forms so you can check the vitamin K content of a food according to how its prepared.

Vitamin A: all your questions answered

I got three questions about vitamin A this week...must be something in the air!

Q. The Nutrition Facts for carrots shows that they are very high in Vitamin A. I thought that vitamin A was only found in animal products and that vegetable sources like carrots contained beta-carotene, a compound that's converted to vitamin A. Can you explain?

A. The type of Vitamin A found in animal foods is called retinol. it's also sometimes referred to as pre-formed vitamin A.  Plants contain precursors to vitamin A (such as beta-carotene), which are converted to retinol in your liver.  The figure that you see in the Nutrition Facts label represents the vitamin A potential of a food--or how much vitamin A your body can either absorb or make from the precursors in that food.

If you scroll down the analysis page to the detail section, you'll see the various vitamin A compounds listed separately (retinol, beta-carotene, lutein, and so on). There, you'll see that carrots contain no retinol but lots of carotenoids. The carotenoids are converted to retinol activity equivalents (how much vitamin A your body can produce from them) and the total is then converted one more time into IU (international units).

Q. In your recent post about vitamin D, you mention that we should be cautious about our intake of vitamin A exceeding 10,000 IU. What are the issues with that? It seems that I get quite a bit of A in my diet (thanks to your website, I now know this!), and there is so much conflicting information out there, it's hard to know what's what.

A. The most important thing to realize is that the concerns about excessive vitamin A intake apply only to retinol and not to vitamin A precursors like beta-carotene.  To see where the vitamin A in your diet comes from, scroll down to the detail section, where you can see how much is in the form of retinol and how much is from carotenoids.

One major concern is that retinol intake of 5,000IU a day can increase the risk of osteoporosis in  older people.  This is the amount found in many multivitamins.  Excessive intake of preformed vitamin A (retinol) can also cause liver damage.  The recommended upper limit for retinol is 10,000IU or 3,000mcg a day.  Note that this is only about three times the recommended daily intake!

The typical diet is not going to exceed this amount. High-dose vitamin supplements and/or taking lots of cod liver oil are the most common culprits. If you take a mult-vitamin, try to find one that provides some or all of the vitamin A activity in the form of beta-carotene. There is no reason to be concerned about getting too much beta-carotene from foods.

Q. Monica, could you please mention something about Retinyl Palmitate as I've seen it in supplements. Is this a synthetic Vit A that we should avoid?

A.  Most of the vitamin A in your liver is stored as retinyl palmitate, which is a compound made of retinol (which is unstable by itself) and palmitic acid (which stabilizes it).  Synthetic retinyl palmitate is frequently used in vitamin supplements and fortified foods and is identical to the retinyl palmitate your liver makes.  Other than the cautions outlined above, there's no reason to avoid it.

Calculating your metabolic rate

Q. How accurate are the various methods of estimating Resting Metabolic Rate? After checking several calculators, I had my RMR tested using a mask that measured oxygen levels for 20 minutes while I read a book. It resulted in an RMR of 720. I was expecting it to be closer to 1200. I'm very confused now.

A. According to this post by our resident fitness expert, Steve Cabral, the test you had done is fairly accurate when properly administered.  So, I'm also a bit surprised at the discrepancy between your test results and the various calculators.  I wonder if it would be worth having it retested.

Obviously, RMR calculators, which take into account your size, age, gender and body composition, can only provide an estimation of your true metabolic rate. For most people, though, these estimates are pretty close. This article explains other factors that can affect your RMR and estimates your RMR using 5 different formulas. When I plugged in my data, all five calculators estimated my RMR within 100 calories.

To estimate how many calories you actually burn in a day, our Daily Needs Calculator starts by estimating your RMR and then estimates how many calories you expend in your normal daily activities, plus exercise, plus a relatively small number of calories attributable to the thermic effect of food (which is bascially the energetic cost of converting food to energy).   The resulting figure is an educated guess about how many calories you expend, which can help you gauge how many calories you should be consuming. But short of going through every day wearing an oxygen/CO2 mask, there's no way of knowing your exact calorie expenditure.

It's tempting to think of the human body as a machine, for which we can simply calculate a "miles per gallon" figure. And in a way, it is a machine, but one so complex that it resists reduction to simple formulas.  In his book Good Calories, Bad Calories, Gary Taubes argues that attempting to manage our body weight by manipulating the calories in/calories out equation is a waste of time anyway, because the body will recalibrate its engine to compensate for changes in input and output. Taubes holds that it's the type of fuel, not the amount, that determines fuel efficiency.

So, I guess my point is that the calculators are merely a way to get you on the green. Once there, you've got to get out your putter. And by that I mean that despite your best efforts to figure out how many calories you should be eating, you may need to adjust that if you find you are gaining or losing weight when you don't expect to.

Anyone else have any experience with RMR testing?

Vitamin D: Now I'm a believer

One of the most electrifying sessions I attended at Andrew Weil's Nutrition and Health Conference in April was one given by Dr. Michael Holick on Vitamin D.  Dr Holick is a well-known, even notorious, name in nutrition research circles. He's been insisting for years that vitamin D deficiency is far more wide-spread and dangerous than anyone realizes and he has a reputation (which he himself promotes!) of being a bit of a kook. 

A few years ago, he was famously booted from the Boston University dermatology faculty for making heretical statements about the benefits of moderate UV exposure (which stimulates the production of vitamin D in the skin) and has been chided and derided by the dermatology establishment ever since.

I thought I had a pretty good idea of what to expect from Holick's presentation; it would be all about the miraculous powers of vitamin D and the dire consequences of deficiency.  I tend to take these sort of Wonder Nutrient presentations with a grain of salt.  When you spend your whole life researching a single compound--like many of these researchers do, I think you can start to lose your sense of perspective. As the old saying goes: When you're holding a hammer, everything starts to look like a nail.

The evidence is always reasonably compelling. And by the end of every Wonder Nutrient presentation, you find yourself thinking, I really should start taking that, and I should probably start recommending it to my patients, too. The problem is that after a few dozen of these presentations, you (and your patients) have a list of 40 nutrients that you "need" to be taking.

It's probably a backlash against too many Wonder Nutrients but, as many of you know, I'm not all that big on dietary supplements. Whenever possible, I think it's better to meet your nutritional needs with actual foods. I myself take very few supplements.  And I have become immune to the persuasive power of Wonder Nutrient lectures.

And yet, after hearing Dr. Holick's presentation, I literally stopped on my way back to the hotel to buy a bottle of vitamin D (1000IU).

Meet Troy: A Body-builder goes vegan

Troy Loferski first got interested in body-building during his college years. Back then, he says, he had a typical body-builder’s approach to nutrition. “I was focused entirely on macronutrients: how much protein, carbohydrate, and fat I was getting. I ate a lot of tuna, eggs, whey protein, and whole grains, but hardly any fruits and vegetables.  I’d read that they were so filling that they made it difficult to consume enough calories to support muscle gains.”

Troy became absorbed by his career and drifted away from training. With his 30th birthday looming, though, he decided in the Fall of 2007 that he wanted to get back in shape. This time around, however, some things had changed.

“I’d been thinking about adopting a vegan lifestyle. Initially, it was for ethical reasons but the more I looked into it, the more I was convinced that the vegan diet was also the ultimate healthy diet and great for longevity. And, of course, there’s a huge emphasis on fruits and vegetables and all the micronutrients and phytochemicals they provide.

“So, I wanted to pursue this healthy diet but I also wanted to start body-building again. At first, I wasn’t sure if it would be possible to do both. But I found a vegan body-building site [veganbodybuilding.com], and then I found Nutritiondata.com.

Troy last year (before becoming a vegan) and now:

“I just kept plugging different foods into the tracking tools to find the combinations that would provide the optimal balance of macronutrients and micronutrients.  I used the Nutrient Search Tool to find foods that had a certain nutritional profile. For instance, that’s how I discovered chia seeds, which I now eat almost every day. I didn’t even know you could eat them…I thought they were just for chia pets! They are a great source of omega-3 fats.

“I still log in everything I eat on most days. The tools on ND are fantastic, especially the pantry and the custom entry tool. The caloric ratio pyramid shows me my macronutrient ratios and the total consumption report helps me track all the micronutrients.

“I eat about 3,800-4000 calories per day with a ratio of about 55% carbs, 20% protein, and 25% fat. That’s way less protein than most body-builders eat—most of them don’t believe it’s possible to do what I’m doing. But my strength and energy levels are fantastic and I feel terrific. Plus, I know that this diet is also really healthy for me over the long-term. My friends and family were a little skeptical about me becoming a vegan, but now that they see how healthy I am, they are very supportive.

“Eating that many calories on a vegan diet can be a challenge. Fruits and vegetables are micronutrient rich but not macronutrient rich. It ends up being a lot of food. I drink 2-3 green smoothies a day, made with pea protein powder, flax or chia, nuts, fruit, and greens. They are 600 or 700 calories each (and no chewing!) so they help me meet my caloric needs. Usually I get about 200% or more of the DV for all the vitamins and minerals, except for sodium, which is usually less than 100%.

“I’m constantly telling other body-builders (and vegans) about Nutritiondata.com. It’s been a big part of making this work for me!”

If you'd like to be profiled as one of our ND Champions, we'd like to hear your story!  Anyone who has used Nutrition Data to make positive changes in their health and lifestyle can be an ND Champion. Click here for details.

A Healthy Brunch for Mom

Mother's Day is coming up! Treating Mom to a festive brunch is a great way to show her you care. But instead of braving the crowds (and calories!) at one of those giant restaurant brunch buffets, why not prepare a healthy brunch at home? Here are several simple and delicious recipes from our sister site Epicurious.com, all featuring fresh ingredients that are in season right now.

Artichoke and Mushroom Fritatta

Asparagus, Peas, and Basil

Fluffy Baked Eggs with Roasted Vegetable Hash

Cauliflower and Feta Omelet

Egg Roulade Stuffed with Turkey Sausage, Mushrooms, and Spinach

At the bottom of each recipe, you'll find a link to a complete nutritional analysis, which you can save to your Nutrition Data pantry. 

For more healthy recipe ideas, our Healthy Dinner Tonight feature delivers a fresh new recipe to your email inbox every day, or subscribe via RSS and view them on your favorite blog reader or igoogle homepage.

Happy Mother's Day!

A question of maturity

Q. What is the difference between immature and mature pinto beans?

A. As you've noticed, when you search the database for certain beans, such as pinto or lima beans you'll find listings for both "mature" and "immature" beans. But you might not have noticed that the "mature" varieties are classified as legumes while the "immature" beans are in the vegetable category.

Beans that are shelled and eaten green are considered immature. Beans that have been allowed to ripen and then dried are considered mature.  So, if you are buying them in the produce or frozen vegetable section, they are immature. If you are buying them in the canned and dried bean aisle, they're mature.

Nutritionally, the mature and immature varieties are fairly similar, except that the mature (dried) beans appear to be significantly higher in folate and selenium.

Which foods slow macular degeneration?

Q. My dietitian suggested I go to your site to find a list of foods that are relatively high in lutein and/or zeaxanthin. I am in the early stages of age related macular degeneration and am told I need these in my diet. I tried imputing Lutein into your search and got no results.

A. The main search box (which you'll find in the upper right corner of every page on NutritionData.com) searches the database by food name but not by nutrient name. To find foods high or low in specific nutrients, use the Nutrient Search Tool, which I used to create this list of foods high in Lutein and Zeaxanthin. (Lutein and zeaxanthin are separate compounds but they are measured together.)  Below is  a screen shot of the the search results.

At the top, you'll see a summary of all the categories that foods high in lutein and zeaxanthin fall into. The category with the most foods (by far) is the vegetable category, which gives you a big hint as to what types of foods you're looking for.  You can click on any category and to see just the results in that category.

In the list of foods, you'll see the amount of lutein + zeaxanthin per 100 grams. By clicking on the name of the food, you'll go to that food's detail page for a complete nutritional analysis. Or click "Add to Pantry" to add some of these nutrient-rich foods to your list of favorite foods.

With a little exploring, you'll see that the foods that you want to emphasize in your diet to hopefully slow the progression of your eye disease include all kinds of leafy greens, peppers, winter squash, and cruciferous vegetables.