Counting carbs: which number matters?

Q. I'm restricting my carb intake to lower my blood sugar levels and lose weight. What number should I use to track my daily carb intake? The number of carbs listed on the nutritional label? The number of net carbs (not exactly sure what that is)? The GI number? The GL number?

A.  Let me see if I can clear up the confusion about what all these numbers mean. Each number tells you something slightly different about the quality and quantity of carbohydrates in a food. You could choose any of them as your "marker." Each has pros and cons, which I'll outline below.

Total Carbohydrates, which is the number you'll find on the nutrition facts label, represents everything that's not protein, fat, or alcohol.  It includes starches, sugars, and fiber.  You can establish a target percentage for total carbohydrates, such as 40% of total calories, or a total number of grams, say, 150g. Your actual target number will depend on whether you're going for a moderate carb, low carb, or very low carb regimen.

One of the advantages of tracking total carbohydrates is that this number is almost always available, whereas a more detailed breakdown of carbohydrates is only sometimes given.  A potential weakness is that the number includes fiber, which is a nondigestible carbohydrates.  A high-fiber food might have more total carbohydrates than a low fiber food but still be lower in digestible (i.e. real) carbs.

Net Carbs refers to the digestible carbohydrates in a food. In most cases, this means the total carbohydrates minus the fiber. In some cases, sugar alcohols--which are a nondigestible form of sugar--are also subtracted from the total.  If you are tracking net carbs, as opposed to total carbs, your target will probably be slightly lower than if you are tracking total carbs.

Tracking net carbs is a slightly more refined version of tracking carbohydrates. One advantage is that it allows or even encourages you to eat more high-fiber foods because these don't blow your carb budget. Eating low net carb foods that are high in sugar alcohols, on the other hand, can lead to digestive distress.

Glycemic Index (GI) refers to a carbohydrate food's likely effect on your blood sugar.  For example, you could choose  to avoid foods with a high GI (70+), limit foods with a moderate GI (40-70), and focus on low GI foods (<40).  This will in effect shift your diet away from sweets and refined starches and toward whole grains, fruits, and vegetables.

The advantage of paying attention to GI is that it helps you to distinguish "good" carbs, which create a gradual and sustained increase in blood sugar, from "bad" carbs, which cause sharp increase in blood sugar. Some of the disadvantages of GI are that there is a limited number of foods for which the GI is known; the GI doesn't reflect serving size in any way (one carrot has the same GI as a hundred carrots); and there is a great deal of variation in how foods affect different people, so the GI may or may not predict how you will respond to a given food.  You can read more about the GI on our GI Topic page.

Glycemic Load (GL) is the GI multiplied by the amount of carbohydrates.  In other words, the GL of one hundred carrots is about a hundred times the GL of one carrot.  You can track the GL of individual foods but it's probably more helpful to look at the GL of whole meals. You might aim to keep the GL of each meal below 25 and the GL for the entire day below 100, for example.  Again, the actual numbers will depend on just how much you want to restrict carbs.

The advantage of glycemic load is that expresses both the quality of a carbohydrate (it's potential impact on blood sugar) as well as the quantity.  I think is a more useful and accurate indicator than the raw GI. The estimated Glycemic Load (eGL) here on NutritionData.com also makes GL figures available for any food and not just the limited number of foods that have been through GI testing. Read more about the eGL on our eGL Help Page.

Total Sugar is one more option that you didn't mention.  As sugar is the form of carbohydrate that has the most dramatic impact on blood sugar and can contribute to weight gain in the form of empty calories, many people simply choose to track and limit their sugar intake.  The World Health Organization recommends limiting added sugars (which do not include the natural sugars found in fruits and dairy products) to 10% of total calories, which is about 50g a day for a 2,000 calorie diet.

One advantage to limiting added sugars is that it focuses on the foods that offer least nutritionally and often do the most damage to health.  One disadvantage is that sugar is not always listed separately on nutrition facts labels.

What's a carb counter to do?

So, to return to your question: Which of these numbers does it make the most sense to track?  It really depends on your approach.  If you have embraced a hard-core, low-carb philosophy, then you're probably going to want to track total or net carbs.  If, on the other hand, you're simply looking for a way to monitor your diet and shift it toward healthier choices, I think tracking GL or total sugars can be quite useful. 

Also, take into account your personality. If you just want a quick and dirty way to keep tabs, I'd go with total carbs, which is readily available on every nutrition facts label. If you're trying to be more exact and are willing to do a little extra leg work, then net carbs and/or GL might be valuable.

Let me know what you decide and whether this was helpful!

Are BMI guidelines for the birds?

Q. I recently read that the standard BMI calculation and guidelines aren't accurate for African-Americans and other ethniticies. Can you explain why and do you have recommendations for ethnic specific guidelines?

A. Your BMI, or body mass index, is nothing more than a way of expressing your weight in relation to your height.  When we say that a BMI of between 19 and 25 is considered ideal, we're really just saying that for every height, there is a suggested healthy weight range. I'm 5'9" for example.  The suggested healthy weight range for me is 128 to 169.  (Click here to look up your BMI)

I think you're probably referring to a recent article in the British Journal of Nutrition  (reported in the Washington Post), which points out that the BMI guidelines are based on statistics gathered in a predominantly Caucasian population.  

Because of differences in average bone density, lean muscle mass, and so on, the BMI guidelines may be misleading for non-Caucasians. For example, it might underestimate healthy weight range for some people of African descent and overestimate the range for some of Asian descent.  Even for Caucasians, though, the BMI is a fairly crude gauge of body composition. For example, it's not a good guide for athletes, who have more muscle mass, or for the elderly, who have lost muscle and bone mass.

The BMI guidelines are supposed is to help identify people who may have too much (or too little) body fat.  Other ways to gauge whether you are carrying around an unhealthy amount of fat include:

Have a fitness trainer measure your body fat percentage.  The recommended percentage depends on your age and gender but as a very general guideline, women should try to keep body fat under 30% and men under 25%.  There are several methods of measuring body fat. The most accurate is also the least convenient: It involves being submerged in a tank of water.  A fitness trainer can get a pretty good estimate using body fat calipers--but good training and technique are essential.  Those scales and hand-held devices that calculate body fat by measuring electrical impedance are notoriously inaccurate.

Measure your waist size. A waist measurement of more than 35" for women or 40" for men increases your risk of heart disease and other diseases.

Calculate your waist-to-height ratio by dividing your waist measurement by your height.   If you are 5'5" and your waist measures 32", your ratio would be 32/65 or 0.49.  A ratio of less than 0.50 is considered healthy.

Calculate your waist-to-hip ratio by dividing your waist measurement by your hip measurement.  If your waist measures 32" and your hips measure 38", your ratio would be 32/38 or 0.84.   As a general rule, women are shooting for a ratio of less than 0.8 and guys for a ratio of 0.95 or less.

Ask your physician for individual guidance.  Your physician sees the whole you, not just a single measurement or statistic. If you're not sure whether your weight is healthy or not, ask your health care provider for input.

Regular versus instant oatmeal

Q. I have been eating instant oatmeal almost daily for a couple of years now. A friend recently told me I have been wasting my time if I thought I was eating it for nutritional reasons. Is instant oatmeal less effective than the regular stuff?

A. Actually, the nutritional differences between regular and instant or quick-cooking oatmeal are so insignificant that the Nutrient Data Laboratory for the USDA has just one analysis which applies to all three kinds of oatmeal.  All three contain the same amount of fiber and the same amount of cholesterol-lowering compounds.

The biggest difference is in taste and texture.  Regular oatmeal contains larger pieces of rolled oat grains and is a little chewier than the instant and quick-cooking varieties. (Ironically, it really doesn't take much longer to cook regular oatmeal than it does to make instant.)

Of course, I'm only talking about plain oatmeal. If the instant oatmeal that you're eating is flavored, then you're also getting a big helping of sugar with your oats. While that doesn't take anything away from the oatmeal, it may add undesirable (empty) calories. Also the little packets of instant oatmeal usually contain a slightly smaller serving than the standard serving of regular oatmeal--so you're getting a slightly smaller helping of fiber.

But rest assured that a serving of plain instant oatmeal is just as nutritious as the same amount of plain regular oatmeal.

Being a carb-counting vegan is a tough job

Q. I'm attempting to maintain a 40-40-20 macronutrient balance with the assistance of your website's tools.  As a vegan athlete, I eat more vegetables and grains than an omnivore, and it is nearly impossible to achieve the 40-40-20 balance without cutting down on either vegetables or carbs, which I believe would not be healthy for me. Is there a way for the caloric ratio pyramid tool to take into account the difference between vegetable carbs and cereal/grain carbs?

A. Not really--but I'm not sure how that would help.  The Caloric Ratio Pyramid shows you how your calories are divided between carbohydrates, protein, and fat but doesn't distinguish between different sources of these macronutrients.  So, your carbohydrate percentage will include the carbohydrates you get from grains, vegetables, dairy products and fruits.

But here's the thing: Although vegetables are almost 100% carbohydrate, most are still very low in carbohydrates. So cutting down on vegetables isn't going to change your macronutrient distribution nearly as quickly as cutting down on grains.  A one cup serving of brown rice, for example, contains 216 calories and 45 grams of carbs. If you are eating 2100 calories a day, that would be 10% of your calories, right there.

A salad made with SIX CUPS of raw spinach, on the other hand, contains just 42 calories and 6 grams of carbs (or about 2% of your 2100 calorie diet).  So, I'm not sure it makes much sense to try to the adjust the carbohydrates proportion of your diet by cutting back on vegetables.

You're absolutely right: Vegans usually end up consuming a diet that's higher in carbohydrates and lower in protein than omnivores. After all, some of the most common vegan protein sources--legumes--contain about as much carbohydrates as protein. Nonetheless, it's possible for a vegan to eat a lower carb/higher protein diet. Tough, but possible. (Whether or not its necessary or desirable is a subject for another post).

ND Tools for customizing your diet

Here on ND, you might want to start by setting your preferences so that results from meat, dairy, and egg categories don't show up in your searches. Then, try a search with our Nutrient Search Tool for foods high in protein and low in carbohydrates. Click on the various categories to refine your searches.

Or, use our super-cool Caloric Ratio Search tool!

 

Position your cursor on the pyramid to select a certain macronutrient ratio and click to see a list of foods that match that ratio. Keep in mind that in a 40/40/20 diet, very few individual foods are likely to be 40/40/20.  But say your typical mealplan always seems to lean too heavy on the carbs and fat and too light on the protein. Put your cursor on the part of the pyramid that's high in protein and low in carbs and fat and click for a list of foods that can help you balance your diet.

Calling all low-carb and athlete vegans:

Seems to me we've had some low-carb vegans commenting on this blog in the past and I know we have some vegan body-builders. Anyone out there want to share some more strategies or resources?

How much protein for a healthy pregancy?

Q. My protein is limited to chicken, fish, eggs. Is there a safe protein shake supplement I can take whilst pregnant ? And how many calories daily should I be consuming ?  I'm 36 years old and weigh 80kg.

A. How many calories you need really depends on your pre-pregnancy weight.  The guidelines for weight gain during pregnancy were just revised because so many women are beginning their pregnancies overweight.

You didn't mention how tall (or pregnant) you are, but if you're of average height (5'4") and your weight was close to 80kg (176lb) before you got pregnant, your pre-pregnancy BMI would have been around 30. According to the new guidelines, you should gain no more than 11 to 20 pounds during your entire pregnancy--and the lion's share of that should be during your 3rd trimester. (Click here to read more about the new guidelines.)  

Because a higher BMI puts you in a higher risk category, I'd strongly recommend that you check with your doctor to get more specific guidance about how much weight you should be gaining and how many calories you should be eating throughout your pregnancy.

In terms of protein, the Institute of Medicine suggests that you get at least 1 g of protein per kg of body weight during pregnancy. So, in your case, at least 80g per day now and 91 to 100 g a day by the end of your pregnancy. Chicken, fish, and eggs are all great source of protein and it may be that you are getting all the protein you need without a protein supplement.   You can use our tools to see how much protein you are consuming from these foods.

If you do decide to use a protein supplement, I'd steer clear of ones with a lot of added vitamins, as you're probably taking a high dose prenatal vitamin already. Look for for one that's very simple and doesn't contain any artificial sweeteners, herbal ingredients, or caffeine.  Again, your obstetrician is there to give you personalized guidance about all aspects of your pregancy, including diet and nutrition!

Healthy Weight Loss: When the usual formulas don't apply

Q. I want to lose 10-15 pounds, which would put me in the middle of the healthy weight range for my height. I've read that losing 1-2 pounds a week is healthy.  However, when I used the daily needs calculator on your site, it said if I cut back to the recommended minimum of 1200 calories per day I could only lose .4 pounds a week.  So which is right?  Could exercise help explain the discrepancy?  Thanks!

Q. It sounds as if the daily needs calculator estimates that it takes about 1400 calories to maintain your current weight. In order to lose one pound a week, you'd have to cut back to about 900 calories per day--and that's lower than we usually recommend that you go for more than a day or two because it increases the chances that you'll be falling short on important nutrients.

If you cut back to the recommended minimum of 1200 calories/day, you'll only be creating a 200 calorie per day deficit, which adds up to the slower  .4 lb/wk weight loss.

Remember, though, that these guidelines are rules-of-thumb, designed for the average-sized person. Most people burn something closer to 1600 to 2400 calories per day. So if they cut back to 1200 calories, they create a much bigger deficit and lose the weight a lot faster. That's what the 1-2 pound/wk estimates that you see are based on.

But 1400 calories is pretty low--suggesting that you're either rather small, somewhat older, and/or fairly sedentary.  Losing a half-pound a week might be a perfectly  appropriate pace for you, especially if you are on the smaller side and this half pound represents a larger percentage of your total weight.

A nutritionist or dietician would be able to give you more personalized guidance about appropriate calorie intake for weight loss.  But you're on to something:  burning more calories with exercise will create a bigger deficit (without you having to dip below 1200 calories) and speed your weight loss.

Related content: 
How many calories do I need?
Diet and Weight Loss Resource Center

Understanding the difference between dietary cholesterol and blood cholesterol

Q. Here in Baja, squid is abundant and we like to eat alot of it. Your site says it is high in cholesterol. Is that bad cholesterol or the good stuff? Can you break it down for me?

 

A. Dietary cholesterol (the cholesterol found in foods such as eggs and seafood) is neither "good" nor "bad."   Those terms are often used to describe different types of cholesterol-containing compounds in your blood.  In your body, cholesterol is bonded to various types of proteins to form packages called lipoproteins. LDL and HDL are two types of cholesterol-containing lipoproteins.

 

LDL is often characterized as "bad" because elevated levels are one risk factor for heart disease. HDL cholesterol is often described as "good" because high levels of this type of cholesterol lower your risk of heart disease.

 

The most recent research indicates that cholesterol from your food has very little effect on how much cholesterol is in your body.  If you're trying to reduce your LDL cholesterol, it's more effective to reduce your intake of saturated fat.

 

In other words, enjoy the squid!

 

 

Eggs and inflammation

Q. Eggs are supposedly an inflammatory food, especially the yolk. Do you still belive that eggs are a good food choice?

A. Like most foods, eggs are a mixed bag.  On the plus side, they are an inexpensive source of complete, high-quality protein. Because many people enjoy eggs for breakfast, eggs can be an alternative (or adjunct) to the usual high-carb breakfast foods and research shows that eating more protein at breakfast helps with appetite control and weight loss.

Eggs also provide vitamin B12 (one of the more common nutrient deficiencies) and selenium, an important antioxidant. They contain no carbohydrate and have a very low glycemic impact.

Among the potential negatives is that egg yolks contain saturated fat and cholesterol. However, the amount of saturated fat is relatively small--about 1.5 grams per large egg. Many don't people realize that eggs contain more monounsaturated fat than saturated fat!  And dietary cholesterol is no longer viewed as a major contributor to blood cholesterol. 

The ratio of omega-6 to omega-3 fats in egg yolks is also very high (about 15:1) and eggs are also somewhat high in arachidonic acid, an omega-6 fat thought to be particularly inflammatory. These last factors are what earn eggs an inflammatory rating here on ND.

However, in my view, it's not necessary or even desirable to eliminate from your diet every food with a negative IF Rating.  Many wholesome foods, such as eggs, fruit, and whole grains, are considered mildly inflammatory and I, for one, couldn't imagine buidling a healthy balanced diet without these foods.

The idea is to use the ratings to guide you towards balance.  In my book, I suggest that people try to avoid extremely inflammatory foods (such as foods high in sugar and fried foods) and ensure that the combined IF Rating of all the foods they eat over the course of the day is in the positive anti-inflammatory range. That certainly leaves room for eggs,

Pastured and/or omega-3 enriched eggs are less inflammatory than conventionally produced eggs. And, as you mention, egg whites are not considered to be at all inflammatory. 

What's more important: adding omega-3 or reducing omega-6?

Q.    I've read that in lowering your ratio of Omega-6 to Omega-3 fatty acids to something approaching 3-1 or 2-1 contributes to health. However, some excellent sources of Omega-3 like walnuts have a ratio higher than that. What's more important--adding more Omega-3 to one's diet or lowering that ratio?

A. This is a great question!  It's essental to have some source of omega-3 fats in your diet, because your body cannot manufacture them from other fats. The National Academy of Sciences estimates that adults need a minimum of 1 to 1.5 grams of omega-3 fat (alpha linolenic acid) every day.  Cold-water fish, flaxseed, walnuts are all rich in omega-3 fats.

The reason so many health experts recommend higher intakes of omega-3 is to balance the very high intake of omega-6 that are typical in a Western industrialized diet.  As discussed in this recent post, "Is taking fish oil environmentally responsible?", people would need less omega-3 fats if they reduced the amount of omega-6 in their diets.  Vegetable oils (such as corn and soy) are rich sources of omega-6.

So, if you're otherwise healthy, you're getting at least the minimum recommended intake of omega-3, and you're maintaining a decent ratio between omega-6 and omega-3, you should have your bases covered.  Certain health conditions, such as high triglycerides, may benefit from higher (i.e. therapeutic) levels of omega-3 fats.

Does cooking with oil create trans fats?

Q. How exactly is trans fat created? If I bake with some (say, 1/4 cup) oil in a batter, does that make trans fats?

A. We’ve all read a lot about the dangers of trans fats.  Most of the trans fat in our diet comes from artificially hydrogenated oils that are still widely used in food manufacturing.  But did you know trans fatty acids also occur naturally? The natural trans fatty acids found in milk and other foods are not considered to be a health threat. In fact, one naturally-occurring trans fatty acid called conjugated linolenic acid, or CLA, is thought to have many beneficial effects in the body.

The trans fats you need to watch out for are the ones created by artificial hydrogenation. These “Franken-fats” are polyunsaturated fatty acids (PUFAs) that have been twisted into an unnatural configuration called a trans-isomer. This means that the molecule contains the exact same number and type of atoms as it did before, but they are arranged in a different shape.

But what a difference that small change makes!  Polyunsaturated fats and their trans-isomers produce completely opposite effects in the body. While PUFAs help to improve cholesterol profiles and reduce your risk of heart disease, trans fats contribute to heart disease by fueling inflammation, raising bad cholesterol and lowering good cholesterol.

What does it take to create a “Franken-fat”?

Artificial hydrogenation involves mixing polyunsaturated oils with hydrogen atoms under very high pressure--not something you could accidentally do at home!  High heat can also cause PUFAs to trans-isomerize into trans fats, if it is applied for long enough. For example, you have to heat a polyunsaturated oil to 240 dgrees F for 16 hours before it begins to trans-isomerize into trans fats--and even then, only a very small percentage (less than 1%) are converted.

As you can see, normal cooking temperatures and times are not nearly enough to create any significant amount of trans fats in the foods we cook at home.

Reference: Wolff, R. L. 1993. Heat-induced geometric isomerization of alpha-linolenic acid: effect of temperature and heating time on the appearance of individual isomers. Journal of the American Oil Chemists Society 70(4): 425-430.