Atkins Diabetes Revolution (27 page)

Some nutritionists use these inconclusive studies to “prove” that a high-protein diet is bad for your bone health. What these people neglect to mention is that the value of dietary protein for building and maintaining strong bones as you get older has been powerfully shown by several recent studies.

In 1998, a carefully conducted study of seven young women compared the effects on calcium absorption of a low-protein and a high- protein diet. The result? Calcium absorption from food was much
lower
on the low-protein diet.
15

Results from the long-running Framingham Osteoporosis Study, published in 2000, showed that eating a diet high in protein has a
protective
effect on your bones as you get older. Among the 615 elderly people in the study, the ones who ate the most protein had the strongest bones—and the ones who ate the least protein had the weakest bones.And over the four-year study period, the people who ate the least protein lost significantly more bone mass than the people who ate the most protein. The connection held up regardless of age, weight, smoking habits, calcium intake, and even estrogen use.
16

Further evidence that protein helps preserve your bones came in 2002, when an important study showed that the combination of a high-protein intake and calcium and vitamin D supplements significantly
slows
bone loss in older adults. The study followed nearly 350 men and women, aged 65 or older, over a three-year period. The participants all ate their usual diet, but half were also randomly assigned to take two supplements containing 700 IUs of vitamin D and 500 mg of calcium. Others ate their usual diet and took two dummy pills, as the study was double-blind: Neither the participants nor the researchers knew which group they were in.At the end of three years,the researchers found that among the people taking the calcium and the vitamin D supplements the ones who also ate the most protein had the strongest bones. Among the people taking the dummy pills, there was no connection between the amount of protein in the diet and the amount of bone loss.
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What this study shows very clearly is that when a high-protein diet is
combined
with high-calcium intake,calcium absorption is increased and bones stay stronger. The amount of calcium needed isn’t very large. In fact, the study participants with the strongest bones took in an average of 1,300 mg of calcium each day—only 100 mg a day more than the recommended daily amount for adults over age 50.

A study published in 2004 was designed to answer questions about calcium balance and dietary protein. After studying 32 people for 63 days on either a lower-protein diet or a higher-protein diet, the researchers concluded that exchanging protein for carbs in the diet, calorie for calorie, may have a favorable impact on the skeletons of healthy men and women.
18
This study supports the idea that replacing carbs with protein may be important to maintaining healthy bones.

When you follow the ABSCP, you get plenty of protein
and
plenty of calcium. The calcium comes from cheese (just one ounce of Cheddar cheese contains 204 mg of calcium) and from all those green leafy vegetables, nuts, and legumes you’re eating now. Along with the calcium you’re getting other nutrients important for bone health,including magnesium, phosphorus, and folic acid. You also get plenty of vitamin D from your food—it’s abundant in eggs, butter, cheese, and fish. To account for individual differences in intake and absorption, we recommend that you take a balanced supplement containing calcium and phosphorus (we’ll discuss supplements in more detail in Chapter 20).

THE STORY ON SOY

In 1999, the FDA approved a heart health claim for soy protein. The agency began allowing food companies to put a statement on foods that provide at least 6.25 grams of soy protein per serving,saying that eating the food could help reduce your risk of heart disease. Does this mean you should eat a lot of soy foods? It’s hard to say. There’s a possible downside to large amounts of soy—among other things,it may increase the risk of breast cancer in women at high risk,such as postmenopausal women and those who have a personal or family history of breast cancer. That’s because soy contains a family of substances called iso- flavones, which have an estrogenic effect; in other words, they weakly mimic the effects of the hormone estrogen in the body, which may trigger breast cancer in susceptible women. Until further research is done, we recommend no more than two servings of soy products of any sort per day for those who may be at risk from excessive estrogen.
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When it comes to protein, we suggest that you get it from a variety of sources, including soy foods now and then (see The Story on Soy above). As mentioned in Chapter 12, eating fish up to twice a week is valuable both for its high-quality protein and the omega-3 fatty acids. Eating a wide selection of protein foods gives you a variety of nutrients, flavors, and cooking possibilities, too—it helps keep your menus interesting.

We recommend that, when choosing your proteins, you select organic meats and eggs. These foods are more expensive, but they make up for it by being more flavorful—and, more important, they do not contain hormones and antibiotics.(And when you buy these products you’re helping to support sustainable agriculture.) Go easy on processed meats such as salami. Even when you choose high-quality brands that don’t contain added carbohydrates as filler, they often contain nitrates and other additives and preservatives, all of which are best consumed rarely.

To avoid the mercury and other toxins that may be in fish, limit your consumption to just two portions a week.A recent FDA/EPA advisory emphasized the benefits of eating fish; however, for young children or those who are planning to get pregnant, are pregnant, or are nursing, certain precautions should be taken to minimize exposure to mercury. The advisory states that these individuals should avoid shark, swordfish, king mackerel, and tilefish because these varieties contain high levels of mercury. When consuming fish, this group should eat a variety of fish and seafood that are lower in mercury and limit their intake to two meals per week.Five of the most common fish that are lower in mercury are shrimp, canned light tuna (albacore white tuna should be limited to once a week), salmon, pollack, and catfish. Check local EPA advisories concerning the safety of fish caught in local lakes, rivers, and coastal areas. As we have discussed, supplemental oils may have the nutritional benefits with fewer potential risks (see page 162).

We hope that after reading this chapter and the last, you now realize the essential roles of both dietary fat and protein in the Atkins Blood Sugar Control Program. However, the ABSCP isn’t just about fat and protein—other foods,including plenty of vegetables and some grains and fruits, are a big part of the program! The next six chapters will tell you all about the wonderful variety of delicious, high- nutrient, low-carb foods you can eat.

ATKINS WITHOUT MEAT

Pictures of juicy grilled steaks appear so often in articles about Dr. Atkins that many people believe only confirmed carnivores can follow the program. Not so! Many vegetarians have improved their health by doing Atkins. Vegetarians who will eat dairy products and eggs (lactoovo vegetarians) have no trouble at all getting enough high-quality protein to replace the carbs in their diets. Stricter vegetarians and even vegans, who eat no animal products at all, have to be a little more creative to get their protein, but it can still be done by eating soy foods and carefully combining whole grains, nuts, and legumes. If you don’t eat animal foods,you also need to be very vigilant about getting enough dietary fat and vitamins,such as vitamin B
₁₂
.

PICK THE PROTEIN

1. Which food
isn’t
a complete protein?

1. chickpeas
   
2. hard-boiled egg
   
3. shrimp
   
4. baked chicken leg
   

2. How many essential amino acids do humans need?

1. 6
   
2. 9
   
3. 22
   

3. When you follow the Atkins Blood Sugar Control Program,you:

1. limit protein to 1 gram per pound of body weight
   
2. eat enough protein foods to assuage hunger
   
3. eat equal amounts of protein and carbohydrates
   

4. Protein is valuable for:

1. stabilizing blood sugar
   
2. satisfying hunger
   
3. building muscle
   
4. all of the above
   

Answers1.a.2.b.3.b.4.d.

Chapter 14

THE ATKINS GLYCEMIC RANKING

In previous chapters, we’ve made reference to the Atkins Glycemic Ranking (AGR). This simple but powerful tool will help you choose the carbohydrate foods that minimize the impact on your blood sugar. All carbohydrates in your diet trigger a rise in blood sugar, but how large that rise is depends a lot on the type of carbohydrate. The way to keep that rise to a minimum is to choose carbs with a low AGR. The AGR is based on important recent research into the effects of carbohydrates on your blood sugar. It’s a cutting-edge concept that takes a little explaining to be understood.

SIMPLE VS. COMPLEX CARBS

We talk a lot about carbohydrates in this book, but what are they? When you remove the protein, fat, water, and ash (minerals) in a food, anything that is left is considered carbohydrate—the sugary or starchy part of the food plus any dietary fiber. For decades, a basic concept in nutrition was that sugary foods are simple carbohydrates and starchy foods are complex carbohydrates. Simple carbohydrates were assumed to be digested quickly, complex carbohydrates more slowly. That would mean that simple carbohydrates affect your blood sugar more quickly than complex carbs. But do they?

Researchers began questioning that basic premise in the early 1980s, and ever since then a growing mountain of scientific studies tells us that the traditional simple/complex carbohydrates division just doesn’t hold up. For instance, under the old theory, eating a starchy complex carbohydrate such as a baked potato should raise your blood sugar slowly. It doesn’t. In fact, eating a baked potato raises your blood sugar even more speedily than eating a few spoonfuls of table sugar!

Unfortunately, current standard nutritional guidelines, which tell you to eat less fat and more carbohydrates, imply that all carbs are pretty much the same. They don’t even consider how different carbohydrate foods impact blood sugar.

THE GLYCEMIC INDEX

There’s a much better way to think about the way carbs act on your body: It’s using what’s called the
glycemic index.
1
The thinking behind the glycemic index (GI) is pretty simple. The GI is a measure of how quickly a carbohydrate food affects your blood sugar. Because pure glucose raises your blood sugar very quickly, 50 grams of glucose (about 3 tablespoons) is the standard reference food for the glycemic index—it’s ranked 100. (The more recent versions of the glycemic index use a slice of white bread as the standard reference.) The effect on your blood sugar of other carbohydrate-containing foods can then be compared with the effect of glucose or white bread to ascertain a particular food’s glycemic ranking.An apple that contains 50 grams of carbohydrates, for example, raises your blood sugar to 55 percent of the level caused by eating 50 grams of glucose, so an apple has a glycemic ranking of 55. (To determine a food’s GI, a volunteer eats a portion of the food large enough to contain 50 grams of carbs; then his blood glucose is measured frequently over the next few hours.)

Instead of thinking of carbohydrates as simple or complex, sugary or starchy, you could think of them as fast-acting and slow-acting. Obviously, if you need to keep your blood sugar normal, slow-acting carbohydrates—those with a lower GI ranking—are the ones to choose. They’re the ones that are digested slowly and cause a gradual rise in blood sugar, followed by a gradual fall.

There’s been a lot of research into the glycemic index over the past few decades, so we now have a pretty good idea of the rankings for hundreds of common carb-containing foods. As a rule of thumb, foods ranked from 0 to 55 are considered low GI; foods ranked from 56 to 69 are medium GI; and those at 70 and above are high GI.Amazingly, there are some foods that have a GI ranking above 100, meaning they elevate your blood sugar even faster than when you eat pure glucose. Remember that baked potato we mentioned earlier? A baked potato served without fat (no butter or sour cream) has a GI ranking of 102!

A major criticism of the GI concept is that it doesn’t take mixed meals into account. After all, you’re not very likely to eat a baked potato all by itself—it would generally be part of a larger meal that would include protein, fat, and perhaps fiber from other foods, all of which slow digestion and your absorption of glucose. That’s true, but it doesn’t diminish the usefulness of the glycemic index. When researchers do studies that involve mixed meals, they use a formula for calculating the amount and type of carbohydrate in the meal so they can factor in the effects of the other foods.

THE GLYCEMIC LOAD

The glycemic index is certainly a useful tool, but it does have some limitations. One big problem is that it’s based on food portions that contain 50 grams of carbohydrate. That means that if a food is low in carbs to begin with, the portion itself has to be large.Also, even within a single food,the GI also doesn’t fully account for the fiber and fat content, which slow the entry of glucose into your bloodstream. For some foods, such as carrots, the extra-large portion size required to comprise 50 grams of carbohydrate makes the GI number misleading.