Diet Fact vs. Diet Fiction
September 12, 2002
Updated April 25, 2005
I wanted to know exactly how to eat, I wanted to know the percentages of each macronutrient I should be having, I wanted to count every gram of carbohydrate, protein and fat as well as watching micronutrient intakes, I wanted to be perfect. So I looked for the official recommendations, I found the USDA food guide pyramid while mistakenly taking the zone guidlines for the government's macronutrient percentages. I tried getting the servings of each food group the pyramid required in the macronutrient percentages that Zone recommended (let's just say that with all the conflicting info on diet, I was confused). I didn't find the government's percentages until sometime later.
I followed the above style of diet with exercise without much success, I didn't seem to be going anywhere and was quite frustrated. My confusion grew when I discovered the zone's percentages weren't right either, no one could agree, somewhere along the way I came across beyondveg.com. I began to look into the non-mainstream, science-based information on nutrition. What I discovered was shocking. Grains (1), (14), sugar (6) and pasteurized dairy (12) (Most people find butter, especially raw butter, the least problematic), the big money makers in the modern world, were the number one causes of a wide array of diseases and ailments ranging from minor to deadly.
I had been disillusioned. The government let me down big time, not only were their recommendations totally wrong and unsupported by science and fact, they were downright dangerous! What they don't tell you is that humans didn't start eating grain until 10,000 years ago when they switched from a hunter-gatherer lifestyle to an agricultural one and since that time, humans have had numerous diseases, our stature has decreased as well as our brain size (13) since our meat consumption fell from 50% (11) to a mere 15%. What they don't tell you is that grain has anti-nutrients in it like phytates which bind to minerals preventing adequate assimilation (1). What they don't tell you is that their extremely high carbohydrate recommendation of 55-65% is too high and quite dangerous and responsible for obesity, diabetes and all sorts of other ailments (1), (14).
I was further led into the low-carbohydrate diet literature which I was avidly against before but now I read it with an open mind. I once believed in all the myths and rumors against low carb diets and would send emails to warn my family about it (being the health nut I am, I like to email them about health related topics). I was going to learn, however, just exactly why those rumors were wrong, but first I learned why low-carbohydrate (lifetime) diets worked and why they were healthy. I would discover the other benefits that many people exerienced on low carb, everything from an increased libido and weight loss (while retaining and even gaining muscle) to the reversal of various diseases, including PCOS (polycystic ovarian syndrome) (4), (8), (9), diabetes (5), (10), (7) and tumors (3) for example.
Humans are designed for a high protein, low carbohydrate diet. For over 2 million years, the human species has subsisted on a diet high in meat and low in carbohydrates (11). There are a few things about our physiology which point this out:
* Brain size in relation to gut size
* Nutritional needs (energy needs, essential fatty acid needs, etc.)
* Body's response to too much insulin
For more than 2 million years (up until the agricultural revolution about 10,000 years ago) the human diet consisted of about 50% meat or more (11), (16).
When early humans increased their consumption of energy and nutrient-dense food (animal food), the gut shrank as well as it's metabolic activity freeing up energy for the brain. Our digestive system is designed for energy dense foods-that is, meat and fat. We don't utilize the energy from fibrous foods very effectively, this would require more metabolic activity in the gut which would come at the expense of our brain. Food high in energy and bioavailability, meat and fat, are required for our small gut and large brain (15).
We also have certain energy and nutritional needs which are most accomodated by animal foods. We need animal foods to get sufficient calories and fat in our diet. Meat contains essential fatty and amino acids which we can either not get enough of from plant foods or none at all. Metabolic evidence shows we have adapted to increased carnivory. Some of the evidence include needs for various amino and fatty acids and some vitamins (which animal foods contain in different, bioavailabe forms for humans) (17).
Excessive amounts of carbohydrate such as that recommended by the USDA, can cause the overproduction of the hunger and fat-storage hormone, insulin. When the body produces too much insulin, the body becomes more unresponsive to it causing your body to produce more. It is this, that leads to diabetes along with other health problems including but not necessarily limited to, high triglycerides, cholesterol and blood pressure and obesity. Higher protein, lower carbohydrate diets have helped symptoms of the problems caused by too much insulin production or something often referred to as "Syndrome X" (14).
There are many myths about low-carbohydrate diets. I'll start with the myths about how low-carb diets are done and other miscellaneous myths and then I will go into the claimed health consequences.
Myths about how low carb diets are done & miscellaneous:
1) Low carbohydrate diets (often Atkins is referred to) exclude all carbohydrates and don't include any or enough vegetables.
I don't know the details of all low carb diets but I know that at least Atkins recommends plenty of low carb, non-starchy vegetables. I've often heard other people who eat low carb say that they eat more vegetables now than they ever have before. Also, for the Atkin's diet, the first 2 weeks are the most restrictive but still call for 20 carbs in the form of vegetables. After the initial phase which is meant to get your body to burn fat stores (benign dietary ketosis or lipolysis) called induction, you gradually add carbs to your diet until you stop losing weight then go back to the level you were losing at before, then when you reach goal you eat enough to maintain. This is generally in the range of 50-100 carbohydrates a day, however, some find they maintain on even less.
People on low carbohydrate diets get most of their carbs from healthier sources such as vegetables, nuts and low-glycemic fruit (the latter being added after induction). Although some would like to have small occasional amounts of grain/sugar foods after they've reached goal and if it's within their carb limit, many find they can never eat grain or sugar again because it causes weight gain, illness and cravings in even the smallest amounts (my guess is that their body no longer has a tolerance to these foods). This way of eating often discourages, especially in the initial phases, unhealthy, processed and refined foods ranging from sugar and grain to most if not all additives and artificial sweeteners (because they cause some to stop losing weight) and focuses on nutritious, natural, whole foods.
2) Low carbohydrate diets exclude exercise.
While it isn't necessary on this way of eating to exercise in order to lose weight (as I have experienced myself if I don't cheat), it is encouraged simply because it's healthy and will help to tone and strengthen your body. Many low carbers do in fact get regular exercise, also, feeling better and having more energy would encourage exercise.
3) Low carbohydrate diets are an extreme, radical fad.
If any diet is a fad, it has to be the high carbohydrate diet which has been around only in the last 10,000 years of our evolution, not enough time to adapt to such a diet. Low fat diets became popular in the 80's and our carbohydrate consumption has increased ever since. We have thrived on a high meat, low carb diet for over 2 million years and this is demonstrated in those who actually stop eating the high carbohydrate diet and instead switch to a diet higher in meat and vegetables and lower in high carbohydrate foods because their health improves. Aside from prehistorical times, low carb diets have been around longer than the 70s. In 1863, William Banting published the Letter on Corpulence.
His diet allowed meat (except for pork) but no bread, sugar, milk, butter, potatoes or beer. In 1906, Vilhjalmur Stefannson went on an expedition to the arctic as part of an experiment to prove that health could be sustained on a 100% meat diet. He lived with eskimos eating only fish. Click here for the whole story.
4) Low carbohydrate diets only work short term, all the weight is gained back.
Low carbohydrate diets are a life-long committment. The real, underlying purpose of low carb diets (and I refer to diets in a long term sense, not the short term) is to eat healthier and eliminate excessive amounts of carbohydrates which have been conclusively linked to a multitude of health problems. If you go back to your previous eating habits, you will gain the weight back. If excessive carbohydrates caused weight gain in the first place, then you can't go back to overloading on them without gaining weight. Also the body of a low carber becomes a fat burner instead of a carb burner and will not tolerate carbohydrates in amounts previous to changing to a low carbohydrate diet.
Most people find that this way of eating is easier to maintain than other diets. Most importantly, a diet which eliminates unhealthy carbs from grain, sugar and milk eliminates cravings for such foods. For any mental attachment to traditional high-carb foods that may remain (even this has been reduced or eliminated for some low carbers), there are low carb substitutes to take their place.
5) Low carbohydrate diets work because they are low calorie.
I don't know about everyone else who switches to a low carb lifestyle, but I've been getting more calories on low carb than with other diets. It seems that it's not black and white as far as calorie consumption among low carbers. Some may get anywhere from 1000-3000. I usually get around 1700-2000+ calories a day. Low carbohydrate diets work for 3 basic reasons. 1) Excess carbohydrates are stored as fat and when you eliminate the excess carbs, you stop storing fat. 2)The body uses it's stored fat for fuel instead of glucose and 3) excess carbohydrates cause a rise in insulin which leads to cravings and causes fat to be stored.
There are many myths about the health consequences of low carbing, which I will name and debunk here.
1) High protein low carbohydrate diets cause high cholesterol and heart disease.
Anyone who has researched the effects or had their cholesterol tested after such a diet knows this is false. Low carb, high fat diets actually lower cholesterol (while HDL, the good cholesterol, rises). Most or all low carbers report lowered cholesterol levels and also that they have been able to discontinue medication.
A study at School of Dietetics and Human Nutrition showed dietary cholesterol to suppress blood cholesterol synthesis (2). Furthermore, monounsatured fat, which are most abundant in meat, loweres cholesterol. Saturated fat, the most demonized of all, has not been proven to cause heart disease. In fact it has been demonstrated in various studies that as the intake of saturated fat, cholesterol and calories increased, so did the general health (18), (19). It has also been shown that low fat, high carbohydrate diets increase human fatty acid synthesis and have negative effects on the cardiovascular system (25).
It is a misconception that cholesterol clogs arteries. The fat found in arterial plaque is mostly unsaturated. Cholesterol, the repair substance, is found on the outside of the clogs, it is not the cause of it. There is, however, a correlation between hydrogenated fats and cancer.
The studies done to prove to the public that animal fats kill actually do not prove this at all. These studies fail miserable at proving dietary fat and cholesterol have any link to heart disease. Studies which claim to prove this link are very poorly and unscientifically conducted making them invalid and and thus not proving the correlation between animal fats and heart disease (19). A high carbohydrate diet, however, has been linked to coronary heart disease (24).
2) Low carbohydrate diets increase risk of cancer.
There is little, questionable evidence to support this at best. There is abundant scientific evidence showing a link between high carbohydrate, low fat diets and cancer. One example of this is the carcinogen known as acrylamide which occurs in cooked high carbohydrate foods. When cooked, starch turns into acrylamide (20). It is also known that cancerous cells need glucose to grow . Ketogenic diets in which carbohydrate levels are greatly reduced until dietary ketosis is reached, have actually shrunk tumors (21), (22). Several types of cancer have been linked to high carbohydrate intakes including breast, lung and bowel cancer among others (23).
3) Ketosis is dangerous, ketones building up in the blood lead to acidosis.
There are two types of ketosis which are often confused by those who are uneducated; benign dietary ketosis and ketoacidosis. Dietary ketosis is merely the burning of fat stores and is a natural state which occurs whenever we burn stored fat which can result from diet and exercise. While there are forms of ketosis related to some health problems, benign ketosis is a natural state experienced in fasting, prolonged exercise and high fat diets (41).
The body regulates ketone production so that ketones don't build up past a safe range in healthy individuals, they are also flushed out of the body through the sweat, breath and urine (28).
Many believe that diets high in protein are too acidic and can lead to acidosis. Contrary to this popular myth, meat promotes acid-alkaline balace because it has vitamin D which is essential to this and is a complete protein (34). Most importantly, however, is the fact that proteins act as a buffer for pH (43).
4) High protein diets cause bone loss.
It has been shown that high protein diets do not adversly effect bone mineral content (27). In one study, a low protein diet which made up 16% of calories caused bone loss (29). A short and long term study in the Journal of Clinical Nutrition had the results that previous studies have found, that high protein in the form of meat does not cause calcium loss (30).
5) High protein/fat diets lead to kidney and gallbladder disease and stones.
This myth is based on the belief that high protein intake causes calcium to be excreted through the kidneys which cause calcium stones. The study referred to under myth number 4 covered this (see ref. 30). The reason that study showed that there is no calcium loss with a high protein intake is because it used meat instead of isolated proteins, the cofactors in whole foods, especially meat, are important and must not be disregarded. It is when you subtract the fat and vitamins that there is a problem (34).
Kidney stones are usually formed from the combination of calcium and oxalate. Oxalates come from grains, fruits and vegetables. A smaller percentage of kidney stones are caused by a build up of uric acid. Citrate and magnesium are substances in our urine that prevent the formation of kidney stones. Water, however, is the most important preventer of stones. Drinking plenty of water flushes out these waste products.
It should also be noted that kidney stones occur in those with a predisposition to them, often people with certain disorders. The idea that a high protein diet leads to kidney stones is over exaggerated at best (31). Further, stable fats (cholesterol and saturated fat) are needed for proper functioning of the kidneys (35). People with kidney disease may need to restrict protein and possibly other certain foods, however, eating meat does not cause it.
As for gallstones, the fact is that a low fat diet presents a risk of developing them, not vice versa. When too little fat is obtained from the diet, the gallbladder does not contract often enough to empty out the bile and gallstones can form (32), (33).
6) The weight lost on low carbohydrate diets are muscle and water.
This is demonstratably false. Low carbohydrate diets improve body composition burning body fat and preserving and even building muscle. People have lost well over a hundred pounds on a low carbohydrate lifestyle, there's no way that is all water.
One common experience among those who adopt low carbohydrate diets is weight staying the same while losing inches. The protein and fat in the diet prevent muscle loss. It has been demonstrated that more lean muscle mass is lost on low protein and low fat diets (36). A high fat, high protein, low carb diet can actually promote muscle growth (37).
As with weight loss on any program, some initial water weight is lost. After this, water balance returns and the body burns fat for energy (it should also be noted that low carbers drink a lot of water so dehydration is not a problem). This is proven all the time with people on low carb diets who continue to lose inches. In one study, men in the lowest carbohydrate test group lost the most fat and preserved the most muscle (38).
7) The brain needs glucose to function.
Just as it is with the rest of the body, the brain will use glucose as fuel first. When glucose is depleted, it runs on ketones (energy delivered from fat) and functions just as well (39). Aside from being able to run on ketones, we can synthesize glucose from dietary protein (44). In addition, low carb diets (or most of them) provide an abundance of essential fatty acids which are essential for healthy functioning of the brain (40). A ketogenic diet does not significantly effect glucose utilization by the brain (protein can be converted to glucose when necessary), however, a diet too low in protein and high in carbohydrates can depress glucose utilization by the brain (42).
8) Low carbohydrate diets are nutritionally inadequate, that's why Atkins recommends taking suppliments.
On the contrary, low carbers, including myself, get more than the recommended RDA of nutrients. Atkins recommend suppliments because of the toxicity of the modern world and also due to the fact that today's foods are more deficient in nutrients because of the poor quality of the soil they're grown in.
As you are probably able to see by now, a low carbohydrate diet is actually the diet we are best designed for. Carb-controlled diets are very helpful in a number of illnesses. Scientific studies reveal that diets high in protein and fat and low in carbohydrates are not as harmful as many people still believe and in fact, cause a marked improvement in health. As misunderstood as the low carb diet is, as a lifelong way of eating it is actually quite healthy.
Low carb.ca, Low carb research and studies.
24. Simin Liu, Walter C Willett, Meir J Stampfer, Frank B Hu, Mary Franz, Laura Sampson, Charles H Hennekens and JoAnn E Manson. A prospective study of dietary glycemic load, carbohydrate intake, and risk of coronary heart disease in US women. Amer. Jnl. of Cl. Nut., June 2000, Vol. 71, No. 6, 1455-1461.
(Search All, "renal function" in title field, 1999 in year field, 5th in the results)
(Click on image of new volume, go to 2000, december, 2504)
37. Phinney, S.D., Bistrian, B.R., Wolfe, R.R., et al., "The Human Metabolic Response to Chronic Ketosis Without Caloric Restriction: Physical and Biochemical Adaptation." Metabolism, Vol. 32, No. 8, 1983, pp. 757-768. 38. Young, C.M., Scanlan, S.S., Im, H.S., et al., "Effect on Body Composition and Other Parameters in Obese Young Men of Carbohydrate Level of Reduction Diet." The American Journal of Clinical Nutrition, 24, 1971, pp. 290-296. 39. Amiel, S.A., "Organ Fuel Selection: Brain." The Proceedings of the Nutrition Society, 1995, Vol. 54, No.1, pp.151-155. Posted at Atkinscenter.com 40. Yehuda, S., Rabinovitz, S., Mostofsky, D.I., "Essential Fatty Acids Are Mediators of Brain Biochemistry and Cognitive Functions." Journal of Neuroscience Research, 1999, Vol. 56, pp. 565-570, posted at Atkinscenter.com 41. Mitchell, G.A., Kassovska-Bratinova, S., Boukaftane, Y., et al., "Medical Aspects of Ketone Body Metabolism." Clinical and Investigative Medicine, 1995, Vol.18, No. 3, pp.193-216, posted at Atkinscenter.com
42. Al-Mudallal, A.S., Levin, B.E., Lust, W.D., et al., "Effects of Unbalanced Diets on Cerebral Glucose Metabolism in the Adult Rat." Neurology, 1995, Vol. 45, No.12, pp. 2261-2265.