Protein is the main building block for every part of your body—and it’s also the mainstay of the Atkins Nutritional Approach (ANA) and the Atkins Blood Sugar Control Program (ABSCP). Protein plays a vital role in stabilizing your insulin and blood sugar, making it easier to lose weight.
PROTEIN FACTS
Most of your body is made up of protein—even your bones and teeth are approximately half protein. Proteins are made up of long, very complex, intricately folded and coiled chains of some 20 different amino acids.Amino acids are small molecules made from atoms of nitrogen, oxygen, hydrogen, carbon, and sometimes sulfur. The amino acids fall into two groups: essential and nonessential.
Essential amino acids are the ones you have to get every day from your meals to maintain good health, just as you need vitamins and essential fatty acids. Nonessential amino acids can come from the food you eat, but your body also synthesizes them from essential amino acids.
You need all those amino acids from protein in order to build new cells and maintain and repair your body.Every single day,for instance, your body needs to make millions of new red blood cells to replace the ones that wear out. Without protein, it could not do so. You also need protein to make the many thousands of different enzymes, hormones, and other chemical messengers that make your body function properly. In fact, insulin is a protein—an intricate chain made of 51 assorted amino acids.
WHAT ARE AMINO ACIDS?
Just as you can make any word in the English language from some combination of 26 letters, your body can manufacture any of the many thousands of proteins it needs by combining the 20 or so different amino acids.
The essential amino acids are:
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
The nonessential amino acids are:
Alanine
Arginine (essential for babies)
Asparagine
Aspartic acid
Cysteine (conditionally essential—in some circumstances you may need this from your diet)
Glutamic acid
Glutamine
Glycine
Proline
Serine
Taurine (essential for babies)
Tyrosine (conditionally essential—in some circumstances you may need this from your diet)
To make your body’s tissues,hormones,and other substances,your cells follow instructions from your DNA and assemble the various amino acids into different proteins. The protein chains can be as short as just two different amino acid molecules (peptides) or so complex that they contain thousands of various amino acid molecules. When exactly the right amino acids are linked together in exactly the right sequence,they coil and fold into the exact shape of that particular protein. The newly formed protein fits, just like a key into a lock, into specialized receptors in your cells—or links up with other proteins to carry out its highly specific job in your body. And when that job is done, other proteins come along and break down the “old” protein so that the amino acids can be reused. Not all the amino acids can be recycled; some are even burned for energy,which is why you need a daily supply of the essential ones.
HOW MUCH PROTEIN DO YOU NEED?
Although there’s a formula to calculate the minimum amount of protein necessary for the standard low-fat, high-carb diet, the amount of protein you need to control your insulin and blood sugar and manage your weight on the ABSCP can’t be calculated by a set formula. Instead, we simply—and strongly—recommend that you eat liberally of delicious high-protein foods such as poultry,fish,beef,pork,and eggs. Eat enough at each meal or snack to feel satisfied but not stuffed.Your body will tell you when you’ve had enough,because you’ll feel satiated. You might be surprised at how quickly you feel full after eating a high- protein meal. That’s because protein helps maintain blood glucose levels within the range for optimum body function. Without the dramatic highs and lows, you’ll feel more energetic and less hungry.
In the end, the amount of protein you eat when you follow the ABSCP may not be that much higher than the amount you ate before you started the program. When the dietary intake of individuals following the ANA has been studied, generally 30 to 35 percent of their calorie intake is protein. Plus, there’s a very positive catch-22 here. Because you allow yourself to eat liberally of the protein foods, and protein is both very satiating and helps control the insulin/blood sugar swings that drive excess hunger, you may end up feeling too full to eat all that much of it! In fact,studies have shown that individuals who reduce their carbohydrate intake actually wind up consuming fewer calories—because they are more quickly satisfied.
PROTEIN SOURCES
The quality of the protein you eat is as important as the quantity. The ideal protein is complete—meaning it contains reasonable amounts of all nine essential amino acids. Meat, poultry, fish, eggs, dairy products, and other animal foods are complete proteins, but grains and legumes are not. Some plant foods contain all nine essential amino acids, but in most of them the quantity of at least one amino acid is very low.For this reason,most plant foods by themselves can’t provide adequate amounts of all of the essential amino acids to meet our protein requirements.Grains,for instance,are generally low in lysine,and beans are low in the sulfur-containing amino acids methionine and cysteine. But people who don’t eat any animal foods can still get enough of the nine essential amino acids by carefully combining different plant foods such as nuts, seeds, legumes, and whole grains. The problem for someone with an imbalanced insulin/blood sugar metabolism is that the foods full of plant proteins typically also contain lots of carbs.
Not all of your protein sources are created equal when it comes to the ABSCP, however. Meats, poultry, fish, and eggs are fair game— they’re pretty much pure protein. Cheese is another good source of low-carb protein. An ounce of Swiss cheese, for instance, contains about 9 grams of protein and only 1 gram of Net Carbs.Watch out for the carbohydrates in milk and yogurt, though.A cup of whole milk or full-fat plain yogurt has 8 grams of protein, but it also contains 11 grams of Net Carbs.If you’d like to get some of your protein from milk or yogurt,try the new reduced-carb “dairy beverage”products and yogurts. The dairy beverage has extra protein and fewer carbs; 8 ounces contain 12 grams of protein and only 3 grams of Net Carbs.
EAT YOUR EGGS
Eggs are such a good source of complete protein that they’re the standard against which all other proteins are compared. Because one large egg contains about 213 mg of cholesterol, however, some doctors recommend limiting or avoiding eggs, thinking they raise blood cholesterol levels. That’s actually true—but the cholesterol that goes up is your good HDL cholesterol.
In a 1994 study, 24 adults who added two eggs to their daily diet for six weeks showed a 10 percent increase in their HDL levels, while their total cholesterol went up only 4 percent. The change in the ratio of total cholesterol to the HDL was not statistically significant.1
Two other studies published since 1999 have found that eggs aren’t the issue.In both of these studies,people were fed eggs and their blood was examined. One author of the study stated that the dietary management of obesity and insulin resistance should emphasize calorie restriction rather than the restriction of fat in the diet.2 In the second study done on healthy, postmenopausal women, Dr. G. M. Reaven stated that large amounts of cholesterol in the diet had little effect on the total or LDL cholesterol level. These results were true regardless of insulin resistance or insulin sensitivity.3
Unfortunately, many people have been brainwashed into thinking eggs are dangerous because they contain cholesterol. James R. came to Dr. Atkins for treatment of high blood lipids. Dr. Atkins stopped James’s statin drug, put him on the Atkins controlled-carb program, and assured him he could eat eggs if he wished. James followed the program but just couldn’t bring himself to believe that eggs were safe. He finally had two scrambled eggs for breakfast one morning—and spent the next ten minutes sitting white-knuckled at his kitchen table, convinced he was about to have a heart attack! He didn’t, of course, and when he came in for his next checkup his blood lipids were better than they had been when he was taking the drug and avoiding eggs.
The nutritional advantages of eggs for people with diabetes are substantial. Eggs have a very low glycemic index ranking and are a good source not just of high-quality protein, but also of vitamins B, D, and E and the minerals calcium, zinc, iron, potassium, and magnesium. Egg yolks get their yellow color from the carotenoids lutein and zeaxanthin, which can help protect your eyes from the sight-robbing condition called age-related macular degeneration.
PROTEIN AND YOUR BLOOD SUGAR
We’ve mentioned the satiety and appetite control benefits of protein, but the advantages of swapping protein for low-quality carbs go far beyond that. Consuming protein is the signal to your body to build muscle.4 This is obviously preferable to consuming an overabundance of refined carbs, which signals your body to store fat!
Adequate amounts of protein also help get your blood sugar under control. This was shown in a recent study that looked at the effect of a higher-protein diet on blood sugar in people with Type 2 diabetes. In this study, for five weeks 12 people with Type 2 diabetes ate a diet with 30 percent of calories from protein,40 percent from carbs,and 30 percent from fat. They then switched for another five weeks to the standard diet recommended by the American Diabetes Association (15 percent of calories from protein, 55 percent from carbs, and 30 percent from fat). What happened? You’ve probably already guessed. When the patients were eating the higher-protein diet, their triglycerides were lower, their blood sugar was significantly lower, and their glycated hemoglobin (A1C) number dropped. In fact, on the higher- protein diet,the A1C went down by 0.8 percent,a significant improvement; it dropped by only 0.3 percent on the standard diabetic diet.5
Note that the participants ate much higher levels of carbohydrates than Dr. Atkins would have recommended for a diabetic patient. His patients typically showed a much larger drop in the A1C, a measure of blood sugar control, when they restricted carbs by following the ABSCP. This would strongly suggest that the improvements for the patients in the study, good as they were, could have been much more dramatic had the carbohydrate amounts been lower.
Other studies have shown the benefit of protein in improving blood sugar metabolism. In one study of overweight women, 12 of the women followed a moderate-protein, reduced-carb (40 percent of calories from carbs) diet for ten weeks. Another 12 women followed the typical American diet, with less protein and 55 percent of calories coming from carbohydrates. At the end of the ten weeks, the women on the higher-protein diet had better results on both the oral glucose tolerance test and the test for fasting blood sugar. Compared with the high-carb dieters, the higher-protein dieters had much more stable blood sugar. Their blood sugar stability continued to improve over the length of the study, while the high-carb dieters experienced more blood sugar swings. And the higher-protein dieters lost more weight!6
These women were not yet diabetic. Their improvement came from decreasing carbohydrates and increasing protein. Yet neither of these studies decreased the carbohydrates enough to show the results Dr. Atkins experienced in decades of caring for patients.7
IS TOO MUCH PROTEIN DANGEROUS?
For people with normal kidney function there’s no evidence that the amount of protein consumed when following the guidelines of the ABSCP is harmful. In fact, there’s some very important evidence to show that eating more protein, especially if it replaces carbohydrates in your diet, is good for you. To take one good example, let’s look at a 1999 study that examined the diets of more than 80,000 women taking part in the Nurses’Health Study.The researchers were interested in the association between protein intake and the risk of heart attack. When they compared the women who ate the most protein with the women who ate the least protein, they found that the group with the highest protein intake had the smallest number of heart attacks. The women who ate the most protein—whether their overall diet was high-fat or low-fat—cut their risk of a heart attack by about 25 percent compared with the women who ate the least protein.8
In the large International Study of Salt and Blood Pressure (INTERSALT), which looked at dietary factors affecting blood pressure among 10,000 people worldwide, the researchers found something similar. The people with the highest protein intake had lower blood pressure than those with the lowest protein intake. This study confirmed what earlier studies had also shown.9
These studies don’t mean, of course, that eating more protein will keep you from having a heart attack or getting high blood pressure, but they do suggest that getting ample amounts of protein could help prevent these problems—and that limiting your protein intake doesn’t help.
HIGH PROTEIN AND YOUR KIDNEYS
Of all the myths about controlled-carb diets, the idea that you eat nothing but meat and that this will somehow destroy your kidneys is the most persistent—and has the least basis in fact. If anything, the ABSCP helps your kidneys by helping you to lose weight, lower your blood sugar, and lower your blood pressure. Contrary to the misinformation put forth about his program, Dr. Atkins recommended eating a wide variety of protein foods, including (but certainly not limited to) red meat.
As a matter of fact, a recent study showed a much greater survival rate in patients with severe diabetic kidney disease who decreased their carbohydrate intake. In this study, one group of nearly 100 patients got 25 to 30 percent of their calories from protein and 35 percent of their calories from carbs. They were allowed to eat protein in the form of chicken, fish, eggs, soy, and dairy sources without restriction; beef and pork were not permitted to decrease iron intake. Another group of nearly 100 patients followed the standard restricted-protein diet for kidney patients, getting only 10 percent of their calories from protein and 65 percent from carbohydrates. Over roughly a five-year period, the high-protein, low-carb patients did much better. In these patients with severe kidney disease, iron intake was also restricted. The researchers concluded that this approach was 40 to 50 percent more effective than standard protein restriction in prolonging kidney function, delaying end-stage kidney disease, and reducing the rate of death from all causes.10
I have seen cases among my patients with diabetes and the metabolic syndrome, whose urinary protein level decreased on a low-carbohydrate plan. Two of my patients are highlighted in this book—Joe McCoy and Pia S. in Chapters 9 and 10 respectively. I monitor urine protein excretion on all of my patients with the metabolic syndrome and diabetes. I have yet to see a case in which urinary protein excretion increased on Atkins. As a matter of fact, I have several patients who have kidney damage from a variety of causes whose protein excretion improved when carbs were controlled. I continue to perform the 24-hour urine test for protein every three months until I have two tests that are stable. Less frequent monitoring occurs as circumstances dictate. If I reach a point where no further improvement in kidney function occurs, kidney- protective medication may be needed. —MARY VERNON
What if you already have Type 2 diabetes? Will eating protein increase your risk of developing kidney disease? It’s very unlikely. There’s little if any evidence to show that normal or even high-protein intake will increase your risk of developing protein in the urine, an indication of kidney disease.11 A recent article points out that severe protein restriction in those with diabetic nephropathy (kidney disease caused by diabetes) does not seem to slow the progression of kidney disease but rather can cause malnutrition.12
Kidney disease is a serious complication of diabetes, but only some people with diabetes go on to have severe kidney disease. Study after study has shown that those who do develop nephropathy eat no more protein than those who don’t.Study after study has also shown that the major cause of kidney disease among people with diabetes isn’t protein in the diet. It’s the combination of high blood pressure, high blood sugar, and high insulin that is deadly—this trio can do a lot of damage to the tiny blood vessels in your kidneys that filter waste products from your blood.Kidney disease in Type 2 diabetics is the perfect example of the vascular consequences of the metabolic syndrome. If you want to prevent damage to the kidneys,controlling your carbs is your strongest defense in the battle to maintain healthy blood vessels throughout your body, as well as in your kidneys. People diagnosed with kidney disease must follow the ABSCP only under medical supervision.
PROTEIN AND YOUR BONES
The next most common myth about the controlled-carbohydrate program is that eating large amounts of protein weakens your bones by leaching calcium from them.Just the opposite is true:A diet high in protein strengthens your bones and can slow down the process that leads to osteoporosis, a condition leading to thin, brittle bones that break easily.
Let’s look at how this myth got started. Several studies in the 1970s and 1980s showed that a high-protein diet might change the amount of calcium excreted from the body, but the results were inconclusive. One study of young men in 1981, for instance, showed that a high- protein diet increased urinary excretion of calcium.13 Another study, however, showed that a high-protein meat intake did not cause excess calcium excretion.14
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.17
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.19
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 B12.
PICK THE PROTEIN
1. Which food isn’t a complete protein?
2. How many essential amino acids do humans need?
3. When you follow the Atkins Blood Sugar Control Program,you:
4. Protein is valuable for:
Answers1.a.2.b.3.b.4.d.