September/October 2004

The carb controversy: 
The truth about the low-carb diet

By Ravi Dykema

      Over the past two decades, we've followed food fads ranging from Atkins to macrobiotics, from vegetarian to the Zone. But no trend has gained as ardent a following-or caused as much controversy-as the low-carb regimen. Critics charge that it increases the risk of osteoporosis, kidney disorders, heart disease and cancer. Supporters say it wards off diabetes and reduces the risk of cancer and heart disease. And, they say, nothing is as effective for losing weight.

      What's the truth? It depends on how you define "low-carb diet." There's no standard. Some folks on a low-carb diet are knoshing on double bacon cheeseburgers with mayo, sans bun. Others are eliminating processed grains and focusing on lean meat, fish, non-starchy vegetables, olive oil and nuts. It's not hard to guess which group will likely have more weight loss and fewer health problems. Another key: Differentiating between healthy carbs, like broccoli and beans, and potentially harmful carbs, like sugar and white bread. Carbohydrates are a broad and varied class of food. Sugar, bread and broccoli are all carbs, but they have dramatically different effects on blood sugar, weight loss and long-term health.

      To help us make sense of the controversy, Nexus interviewed Michael Eades, M.D., co-author (with his wife, Mary Dan Eades) of Protein Power and The 30 Day Low-Carb Diet Solution. The husband-and-wife team also created the website, Protein Power (www.eatprotein.com). Here, Eades talks to Nexus publisher Ravi Dykema about the myths, the realities and the flat-out lies about a low-carb diet.

 

The benefits of a low-carb diet are being confirmed over and over in studies: It lowers blood lipids, stabilizes blood sugar and promotes weight loss.   On a given number of calories, people actually lose more weight on a lower carbohydrate diet.   Pesticides and organophosphates in the environment are a real health problem; they can also play hell with weight loss. People are concerned about beef being a source of environmental toxins; but if you really want to get good concentrated organophosphates, eat salmon. A low-fat diet as a panacea was nothing but a hypothesis. It was based on zero medical evidence. It just sounded good. There's really no health problem or issue that gets worse with a low-carb diet. It has never been shown that protein in a normal kidney causes any damage at all. What causes damage is elevated glucose. High-protein, low-carb diets are not really all that high in protein. They're about the same as the standard American diet.  Some people are saying, "Just cut your carbs, and you can eat all the fat and meat you want." I think that's going to be a disaster. If you do a low-carb diet the way it's supposed to be done, you shouldn't have any worries about getting plenty of fiber and phytonutrients.

RD: What are the main arguments supporting the low-carb diet?

ME: I look at everything through what I call a Paleolithic lens. We as humans, as a species, have spent a long time on the earth walking upright, separated from the apes. If you look back at that time period, at least four million years ago, you have to come to the conclusion that natural selection has adapted us to perform optimally on the diet that's at hand, or that was at hand during those times.

      On the threshold of the development of agriculture, humans were large and robust. Their bones for a given height were thicker than ours are now. They didn't have tooth decay-it was practically unknown. They didn't have signs of iron deficiency anemia or scurvy. They were muscular and strong. They were really pretty magnificent physical specimens. When agriculture came along, all that changed. Stature shrank, and the signs of anemia and scurvy became much more widespread. Signs of infection and malnutrition were also more widespread. None of these conditions existed before the advent of agriculture. Obviously, we evolved to perform optimally on the diet at hand prior to agriculture because we haven't had enough time since then to adapt to it.

 

RD: But close relatives of our ancestors, like gorillas and chimpanzees, were vegetarian.

ME: The chimpanzee is not really a vegetarian. Chimpanzees are basically hunters. They actually get a fair amount of their food from meat sources. Vegetarians would have you believe that that's not the case, but the anthropological literature certainly confirms that they are hunters-in fact, they're pretty vicious hunters. And baboons are certainly non-vegetarian.

      But be that as it may, we're neither chimpanzees nor gorillas. We all branched out about six million years ago from the chimpanzee, which is our nearest relative. Agriculture came along 4,000 to 8,000 years ago, depending on where it was in the world. And 8,000 years isn't enough time to adapt genetically to a high-carbohydrate diet. If you look at the anthropological evidence, it's pretty clear that we were meat eaters. I think that's one big argument for the low-carbohydrate diet; we've had many, many years to adapt to it. 

      Studies on the hunter-gatherer populations that exist today show that, on average, they get 65 percent of their calories from animal sources and 35 percent of their calories from plant sources. There are variations-some get almost all their calories from animal sources, and others get most of their calories from plant sources. But if you average them all out, it's about 65 to 35, which makes sense. If you look at plants that grow wild, those that would have been available to our pre-agricultural ancestors, they're not very carbohydrate rich. In order to be able to get the 3,000 calories they would have needed to exist, they would have had to gather a ton of these foods. It's unlikely that they did that when game was so widely available.

      The anthropological literature's pretty clear that we were meat eaters. That's one big argument in my mind in favor of low carbohydrate diets.

RD: But a lot of studies have shown that a diet high in fruits in vegetables is preferable to a diet low in fruits and vegetables.

ME: That's true. But if you just fed people fruits and vegetables and no meat, that wouldn't be healthy, because they wouldn't get any vitamin B12. Vitamin B12 is an essential vitamin, and you can only get it from animal sources. There's another indication right there that we're not vegetarians. Studies have shown that when people increase their consumption of fruits and vegetables, they seem to have lower rates of cancer and heart disease; but those people are usually compared to people who eat the standard American diet, which is basically junk food.

      A well-planned, low-carbohydrate diet is filled with a lot of good-quality fruits and vegetables. In fact, a low-carbohydrate diet includes the most nutrient-dense fruits and vegetables of all; the diet excludes really starchy vegetables, which are not particularly nutrient-dense anyway. We encourage people on a low-carbohydrate diet to eat lots of berries and colorful fruits and vegetables, and stay away from potatoes and more starchy things that aren't particularly nutrient dense anyway.

 

RD: But isn't an optimal diet one that includes a wide variety of foods, like whole-grains, beans and peas? I'm thinking in particular of the Nurses' Health Study (a 20-year study of diet and health involving more than 75,000 women).

ME: In the first place, the Nurses' Study diets have laid to rest the old idea that fat consumption is a driving force behind breast cancer; in the study, there was no relationship between fat consumption and risk of breast cancer. But you have to understand that these were epidemiological studies, which are absolutely valueless for proving a point. All they're good for is for creating a hypothesis that can be tested. Otherwise, they're pretty much worthless.

      If you read a lot of the medical literature, as I do, you hear that statement made over and over again, because people try to use epidemiological studies to prove something; you just can't do it. Let's take the nurses study, which supposedly showed that consuming whole grains helps prevent disease. First of all, who's going to consume whole grains? Probably more health-conscious people. And more health-conscious people do other things-like eat more fruits and vegetables, or exercise more-than other people do. So even though an epidemiological study may point out correlations, it doesn't show a cause and effect. Correlation is not causation.

 

"The benefits of a low-carb diet are being confirmed over and over in studies: It lowers blood lipids, stabilizes blood sugar and promotes weight loss."

RD: Other studies have suggested that a high consumption of red meat was correlated with a higher risk of colon cancer. How would you interpret that? 

ME: Again, that's data from an epidemiological study and, again, correlation isn't causation. Also, Michael Hill, an epidemiologist in England , has published more than anybody else on meat consumption. The sum total of his data, which looked at half a million subjects, have found that, if anything, fresh meat is cancer-protective. The only correlation he's found with meat consumption and cancer is in processed meat.

 

RD: When you say "fresh meat," do you mean just non-processed?

ME: Yes-for example, a steak, versus hot dogs or cured meat. That's the only correlation Hill has found, and he's published probably more than anybody else. Again, these are all epidemiological studies. But if you get into the hard science, one thing we absolutely do know is that elevated insulin levels are bad for you. We also know, pretty conclusively, that 75 percent of people tend to over-secrete insulin in response to a carbohydrate-rich diet. These are young, healthy people. People also tend to become more insulin resistant as they age.

      In a normal glucose response, when carbohydrates are eaten, blood sugar levels rise quickly, then they plateau and fall off after time. When carbohydrates are eaten, the pancreas secretes a substance called insulin to keep levels of sugar in the blood from getting too high. A number of studies done in the 1980s found that young, healthy people had a wide variation in the amount of insulin they produced after eating carbohydrates. Young people whose parents had diabetes, were overweight or had high blood pressure produced more insulin to keep their blood sugar normal. Basically, they're in the early stages of developing insulin resistance, because it already requires more insulin for them to keep their blood sugar normal.

      We know that elevated insulin levels and insulin resistance are harmful, and that they're a driving force behind what's called metabolic syndrome (also called syndrome X, a group of metabolic disorders that increase the risk of heart disease, including insulin resistance, hypertension, low HDL, high LDL and high triglycerides). We also know that if you can correct insulin resistance and make people more insulin sensitive, they're going to be healthier. You can do that one of two ways: You can follow a low-carbohydrate diet, or you follow a calorically restricted diet. In one study, people were divided into two groups and put on one of two diets: A higher-carb and a lower-carb. Both diets had 1,000 calories a day, and both had 75 to 80 grams of protein. After six weeks, the people who were in the higher-carb group showed a decrease in insulin levels of about eight percent; those who were in the low-carb group dropped their insulin levels by almost 50 percent and improved their blood lipids and triglycerides.

      This is being confirmed over and over in studies: a low-carbohydrate diet lowers blood lipids, stabilizes blood sugar and promotes weight loss. The evidence is pouring in-not a week goes by that there isn't another paper confirming this. What's really interesting is that a lot of these papers show that on a given number of calories, people actually lose more weight on a lower carbohydrate diet. This has everybody scratching their heads because they think it's in violation of the laws of thermodynamics and conventional wisdom.

 

RD: What is the conventional wisdom?

ME: A calorie is a calorie. So if two different groups of people both consume 1500 calories, no matter what those calories are made of, they'll lose the same amount of weight.

 

RD: But it actually takes more energy to metabolize a protein calorie than a carbohydrate calorie?

ME: Right. A lot more. And you've proven yourself smarter than the vast majority of scientists out there who still don't understand that.

      There are four laws of thermodynamics; the first and second are directly related to our discussion. The first law says that energy is neither created nor destroyed-that's the old "a calorie is a calorie" theory. The second law says the entropy of the universe is always increasing-so whenever you have any kind of a process, whether it's running a gasoline engine or metabolizing food, it is not 100 percent efficient. There's always an increase in entropy, which means an increase in disorder in the universe; so even though energy goes from A to B, B doesn't have as much energy as A because some has escaped as entropy. 

      When people reduce their intake of carbohydrates, even keeping the protein the same, it's a more energy-inefficient process. Some cells in the body must have glucose to function-brain cells, red blood cells, cells in the retina, some others. Their glucose requirements add up to about 150 or 160 grams a day. So your body has to somehow get 150 or 160 grams a day of glucose. If you're eating the standard American diet that's giving you 250-plus grams a day of carbohydrate, it meets the needs of all these cells, and it doesn't require very much energy to do that. 

      If, on the other hand, you're on a low-carbohydrate diet and eating only 30 to 40 grams a day of glucose or carbohydrate; where will the other 120 grams come from? The body has to make it, which it can do very easily from both protein and, to a certain extent, fat. But it has to manufacture it, and that's an energy-consuming process called gluconeogenesis, or the making of new glucose. Right there is plenty of evidence that a low-carbohydrate diet is more energy consuming than a higher-carbohydrate diet.

      Another interesting point: the red blood cells can use only glucose, but the brain and the muscles adapt really well to using ketones, a byproduct of fat metabolism. So when you lower your glucose or carbohydrate consumption, the brain and lots of other organs in the body, including the muscular system, start burning ketones for energy. And to make ketones, the body has to partially break down fat, which is an energy-intensive process.

 

"On a given number of calories, people actually lose more weight on a lower carbohydrate diet."

RD: I see. But what about long-term weight loss? In a recent study, people on a low-carb diet lost weight more rapidly than a control group on a higher-carb diet, but the low-carb people ended up gaining it back. How do you interpret those results?

ME: Well, if you really read that study, you'll find some interesting results. Most of the time, what people read are the press reports about these studies; they don't read the studies themselves. But if you actually read the study, you'll see that the people on the low-carb diet were on a strict low-carbohydrate regimen early on. They were told to stay on that strict diet for a few weeks; once this time period was over, they were instructed to start adding carbohydrates back into their diet. When they started adding carbs back, their weight loss fell off. By the time they were at the end of the study, they were eating the same thing as basically the people who were on the higher-carb diet.

 

RD: So the test group didn't really stay on a low-carb diet.

ME: Exactly. That study was reported in the May 22, 2003 issue of the New England Journal of Medicine. In that same issue appeared another study that was done the right way. In the second study, researchers put one group on a fairly rigorous low-carb diet and the other group on a high-carb diet, and they kept the diets the same throughout the study. Those study results were what you would expect-people on the low-carb diet had lower blood lipids, lost more weight and stabilized their blood sugars. Everything good happened in that study, because participants stayed on the low-carb diet the whole time. In fact, that was our specific diet that they used in that study.

 

RD: So we can expect to lose weight and improve certain markers of health on the low-carb diet. But what about chemicals in the food supply that are concentrated in meat and fish? Do you see this as a problem?

ME: I think pesticides, organophosphates, other chemicals in the environment are a real problem. I see them as a problem with weight loss, too, because these things really can play hell with your weight loss. But there's more to this discussion. 

      Cows and virtually all meat sources are basically herbivores, so there's really not a whole lot of concentrating that they do-really, it's just one step between the grass and the cow and you. There's a quote from Andrew Weil who says that cows are big, they're high on the food chain and they concentrate all this stuff. Which is bullshit. No matter how big they are, they still eat grass. They're only one step more of concentration. He makes this case about how he never eats meat because of that, but he eats fish. Now think about it. What concentrates the most pollutants of all? Our fish. Fish are true carnivores. Big fish eat smaller fish, who eat smaller fish, who eat smaller fish. If you really want to get some good concentrated organophosphates, eat some salmon. Eat some tuna. Yet people who insist that cows concentrate environmental chemicals then tell people, "Yeah, it's good to eat fish."

      If you're eating a non-carnivore, you're just one step away from eating the grass yourself. You can also eliminate the vast majority of organophosphates and other chemicals if you choose the leanest cuts of meat and cut off the visible fat, because fat is where all that stuff is stored. Better yet, eat grass-fed beef; they're leaner than lot-fed beef.

      As for weight loss: I just read an interesting study hypothesizing that one of the reasons people have so much difficulty maintaining their weight loss is the fact that humans, just like cows, store organophosphates in the fat cells. When you lose weight, these chemicals are released into the bloodstream, where they can play havoc with all kinds of body systems, including your whole biological system geared to weight loss. The study found people who had lost weight had higher serum levels of organophosphates than people who hadn't lost weight. That could be a reason it's so difficult for people who have lost weight to keep it off.

 

"Pesticides and organophosphates in the environment are a real health problem; they can also play hell with weight loss."

RD: It sounds like a vast number of studies are supporting the low-carb diet. Do you think conventional wisdom is going to shift, so that this will be the recommended diet in the near future? 

ME: Yes. It's already moving in that direction. If you look back six to eight years ago, people were basically saying, "Eat all the carbs you want-just decrease your fat consumption." Now, the general advice is to avoid refined sugars or refined carbohydrates in favor of complex carbohydrates. So conventional wisdom has already taken a step in that direction. What's interesting is that the idea of a low-fat diet being a panacea was nothing but a hypothesis to begin with-there were no studies to support it. It was based on zero medical evidence. It just sounded good. Now that the low-fat diet is actually being tested, it's coming up short against the low-carb diet in virtually every way. Every time the low-fat diet goes up against the low-carb diet, the low-carb diet is shown to be vastly superior.

      There are practically miraculous changes in people when they shift to a lower-carb diet.  To my way of thinking, it's just a shift back to the way that nature designed us to eat before the advent of agriculture. I don't think there's any magic to it--it's just what we're genetically designed to eat by the forces of natural selection over many, many millennia. I think as time goes on and more and more of these studies accumulate, the general thinking is going to shift. 

      I just got back from the first-ever low-carb scientific conference put on by Kingsbrook Jewish Medical Center in New York . They had 20 people there who were presenting their data; they all started out as skeptics, and as their studies went on, the results that they had were just indisputable. One guy from the University of Minnesota had a group of diabetic patients; he cut down their consumption of carbohydrates just a little bit, and got pretty good results, so he decided to cut them even more, got even better results. Then he cut them some more and got even better results. Now, he's got a study going where carbs are cut to the bone, and he's just absolutely convinced about the validity of a low-carb diet. When you're doing your practice and you see it day-in and day-out with patients, you can't help but be convinced.

 

RD: You mentioned diabetes. What are some other conditions that respond to a low-carb diet?

ME: There's absolutely nothing that brings down triglycerides faster than a low-carb diet. Triglycerides-fats in the blood that are related to a higher risk of heart disease-are really carbohydrate-driven. High density lipoprotein (HDL), the "good" cholesterol, is fat-driven. In other words, you make more HDL when you increase the fat in the diet. That's been the big problem with low-fat diets; they lower LDL, the "bad" cholesterol, a little bit, but they lower HDL much more, percentage wise, so the ratio of those two worsens on low-fat diets.

      A Harvard study published a few years ago looked at all of the various lipid parameters: LDLs, HDLs, triglycerides, different particle sizes, the whole thing, and tried to come up with the one they felt was the most predictive of who was going to develop a heart attack. It turns out it's the triglycerides divided by the HDL. The lower that factor is, the better your prognosis is for not developing a heart attack. So if you lower triglycerides, which you can do easily by restricting carbs in the diet, and increase HDL by increasing fat, bingo--you've lowered that ratio and reduced your risk of heart disease. There's another lipid parameter called lipoprotein-a that's a risk factor for heart disease. What makes it go down more than anything is increased consumption of saturated fat
      A low-carb diet also stabilizes blood sugar, and it's so potent that you've got to really be careful with people who are diabetics; if you're not careful, you can bottom their blood sugar out if they're on medications. When we're working with type II diabetics, we take them off all their medications before we start them on a low-carb diet, because in many cases they never have to go back on, and on other cases, they may go back on for a little while, but at much reduced doses. Sam e thing with high blood pressure. About 75 percent of people with high blood pressure respond just fabulously to a low-carb diet. Again, you've got to be really careful with medicine; they can start to pass-out because their blood pressure goes so low.

 

Some people are saying, "Just cut your carbs, and you can eat all the fat and meat you want." I think that's going to be a disaster.

RD: So people who are experimenting on their own with their low-carb diets should be careful if they are on medications for diabetes or high blood pressure.

ME: That's right-that's how powerful the diet is. The low-carb diet is also great for treating sleep apnea; people respond even before they're lost weight. It can get rid of fat in the liver. And a low-carb diet absolutely, 100 percent of the time, gets rid of GERD, gastro-esophageal-reflux-disorder, which is hugely widespread. I think Prilosec, a drug for this bad heartburn, is the number-one selling prescription drug-that's how prevalent it is.

      There are some other areas that haven't been as widely studied. For example, we know that women who reduce their intake of carbohydrates reduce their C-reactive protein. There's a theory now that cardiovascular disease is not really lipid-driven, that it's inflammation-driven. And C-reactive protein is a marker of inflammation that goes down in women who decrease the carbohydrate in their diet, which means they're decreasing inflammation. Another marker, fibrinogen, also goes down. There's really nothing that gets worse with a low-carb diet.

 

RD: What about the theory that a high-protein diet is hard on the kidneys?

ME: That's absolute nonsense. It's even referred to as a myth in the medical literature, but it's a myth that just won't die. It's never been shown that protein in a normal kidney causes any damage at all. What causes worse damage is elevated glucose. But for some reason this has gotten stuck in the minds of people who bash low-carb diets-that it "kills" the kidneys. But many studies have shown that, if anything, a low-carb diet has a positive effect on kidney health.

      In a study done in Israel a few years ago, an internist named Marion Bloom took people who were long-term, high-protein eaters and matched them by age and sex with people who had been vegetarians for at least seven years; she plotted their kidney function as a function of age, and the two curves were right on top of one another. There's just no evidence that a high-protein diet is bad for the kidneys. If you go to Wendy's and have a bacon double cheeseburger and an order of fries and a Coke, is that going to kill your kidneys? Well, no. It's a crappy diet, but it's not going to kill your kidneys. If you get rid of the bun and the French fries, and have unsweetened iced tea instead of Coke, now you're suddenly on this high-protein diet that's going to kill your kidneys?

      That brings up another point: High-protein diets are not really all that high in protein. They're about the same as the standard American diet. So it's more about taking away carbohydrates than adding protein.

 

RD: What about the idea that a low-carb diet causes osteoporosis, because high protein consumption leaches calcium from the bones?

ME: That actually is true. Meat is what's called an acid-forming food; it contains amino acids which are acidic. So when you eat meat, it causes a mild acid condition in the body that has to be buffered. The way the body buffers that acid is by leaching calcium, which is alkaline, from the bones. Over a long period of time, you're going to have a net calcium loss from bones. But there are two other things that are equally as bad about leaching calcium from the bones, and that's grain products and cheeses. 

      Other foods have the opposite effect-that is, they're alkaline-forming foods. These include green leafy vegetables, especially spinach, and colorful fruits and vegetables. If you combine acid and alkaline foods, you'll prevent leaching from the bones. That's why I never recommend that somebody just go out and eat a meat-only diet. I don't think it would hurt them in the short run, I don't think it would hurt them in the long run, in terms of cardiovascular health, but I do think it would cause osteoporosis in the long run.

      We said two other foods-grains and cheese-are equally as bad as meat. On a low-carb diet, you get rid of the grains component, which is a step in the right direction. As for cheese, many people encourage those on a low-carb diet to eat cheese because of the calcium; I don't. I encourage people to eat softer cheeses and stay away from hard ones-which are more acidic-and to eat lots of green leafy vegetables, berries and colorful fruits and vegetables. If you do, you will buffer the acidity caused by the meat and end up having no net calcium loss.

 

We've seen people who have gone from having apparently clean arteries to needing a stint placement in a year or two on low-carb diets. Many people around the world live well into their 90s and 100s on very high-carbohydrate, low-fat diets with modest protein. A food-pyramid diet isn't the healthiest way to eat. It's just the federal government's compromise between what the science says and what corporate America is willing to put up with. No studies longer than a year have looked at the effect of a low-carbohydrate, high-protein diet on weight loss, or any other effects in the body. Many of our health problems have less to do with macro-nutrients and more to do with the kind of processing food has undergone between when it was raised and when we eat it.

RD: Do you think that's how the American public is adopting the low-carb diet-eating lots of colorful fruits and vegetables, and eliminating grains? It seems to me that they're eating more and more meat and fat.

ME: That's what worries me about the low-carb diet. The big mistake the low-fat people made was in saying, "Look, if you just keep your fat consumption to 30 percent of calories, you can eat all you want and you'll be okay." That really encouraged overeating. Now, I worry that the low-carb people are out there saying, "Just cut your carbs, and you can eat all the fat and meat you want." I think that's going to be a disaster-if your calorie consumption goes way up, it overcomes the metabolic advantage you have on a low-carb diet.

 

RD: And what about fiber? Isn't that an issue on a low-carb diet?

ME: Yes, but if you eat all the things that we recommend people eat, you'll get plenty of fiber-probably more than you would get on the standard American diet. For example, we have people use pureed cauliflower and celery root, which has a ton of fiber, in place of mashed potatoes. Just one serving of that will give you about half your fiber for the day. So if you do a low-carb diet the way it's supposed to be done, you shouldn't have any worries about getting plenty of fiber and plenty of phytonutrients. 

      That's the key: Doing a low-carb diet the way it's supposed to be done. I read something from a research company that had interviewed a huge number of people-about 11,000-who said they were on a low-carb diet. On that diet, the men were eating an average of 145 grams of carbohydrates and the women were eating an average of 109 grams of carbohydrates a day. That's not low enough to get your insulin down substantially or to realize the metabolic advantages of a low carbohydrate diet. It's a step in the right direction, but it's really not enough. A lot of people are saying "I'll only eat half the baked potato with my steak." That's just not going to work. And if people are eating a lot more meat, with only a small reduction in carbohydrates and no increase in fiber, they may actually be increasing their risk of certain diseases, like bowel diseases.

 

RD: So what would happen if people were left to their own devices-that is, what would we instinctively eat?

ME: That's a good question. In the 1970s, an English researcher named John Yudkin put a group of people on an "eat-whatever-you-want" plan. He carefully monitored what they ate over a period of time, and realized they were consuming between 2400 and 2500 calories, which is about what people now eat, if you average men and women. He also found that they ate about 45 percent carbohydrate, 15 to 18 percent protein and the rest fat. Now, fat consumption is lower and carbs are higher, but protein consumption is about the same.

      Then Yudkin put these same people on a low-carb diet. He told them what to avoid-potatoes, bread, rice, baked beans, corn, that sort of thing-but otherwise to eat all they wanted. When he analyzed what they ate, he found they had dropped their caloric intake from about 2450 to about 1560, and kept their protein pretty much the same. What was really amazing is that they decreased their consumption of fat as well. Even though the percent of fat was higher, the absolute amount of fat was lower.

      Additionally, starchy foods are not very nutrient-dense-all they're dense in is carbs. A potato, for example, doesn't really have anything other than carbs. The same goes for rice. Beans and corn have a few more nutrients, but not enough to make it worth the huge carb load. You could get 20 times the phytonutrients by eating a piece of broccoli or some asparagus or a tomato.  

What's the beef? The downside of the low-carb diet