Friday, October 21, 2011

Eating lots of fat to lose weight

Classifying foods into the broad categories of healthy and unhealthy misses important nuances. Disease is associated with bacteria, viruses and prions, so foods that are properly cleaned are not unhealthy in the sense of causing disease. It is true that eating only a single food item exclusive of others would deprive the body of vitamins, but if it is not a poison that causes direct harm to the body, it is not unhealthy.

Some people swear by their convictions that organic foods are healthier than foods produced on large corporate farms. Even as a young adult, I was puzzled over the concept of organic foods. In 10th grade chemistry class, we learned that organic molecules are by definition ones that contain carbon atoms, which are covalently bonded to each other and to other atoms. Aren't all foods organic? Petroleum is organic, but it would certainly make one sick if ingested. Some of the most potent toxins are organic.

As I learned later in life, "Organic" is a trademark that describes how foods are cultivated. Manure may be used instead of the chemicals found on larger commercial farms, and fruits and vegetables are harvested later so that they ripen naturally rather than in cardboard crates. If people are willing to pay a higher price for a particular farming practice, so be it.

Conservatives may turn to Fox News for their daily dose of self deception, while liberals may enjoy shopping in hippie-like co-ops to fortify their beliefs in the spiritual purity associated with ingesting so-called healthy foods. In the end, scientifically reliable sources and the preponderance of evidence should rule the day.

Several years ago, I spent part of an evening at a ski lodge watching a program on an investigative TV news magazine. An independent laboratory did a chemical analysis of fruits and vegetables grown on large corporate farms and found no trace of the chemical fertilizers and pesticides used to enhance yield. Ironically, the "organic" foods were found to have high levels of bacteria that cause intestinal diseases. When confronted by these facts, the spokesman for the organic farmers stated very confidently that "when washed properly, 'organic' foods were at least as healthy as foods grown on non-organic farms." He is right in the sense that "at least" also includes "is equal to." In other words, if you wash your organic lettuce very carefully, it will be equivalent in safety to the lettuce sold by large and evil corporations.

The food pyramid suggests that a diet should be high in grains and low in fat. Fruits and vegetables are good and meat in large quantities is bad. One would assume that the food pyramid, introduced by the U.S. Department of Agriculture, is based on solid science; but, it is not.

Many years ago, my wife introduced me to the low carbohydrate Atkins Diet. Being the mid 1990s, there was far less information available on the internet than today; but, I had access to databases of scientific journals. What few studies were available in medical journals at the time did not seem to indicate any adverse effects of such a diet. In contrast, all of the people around me thought me crazy to consider eating lots of fat to lose weight. "That diet sounds mighty dangerous," they would opine. A common criticism of low carbohydrate diets is repeated on many web sites. Consider the following:

Dr. David E. Norwood writes [sic] in an article about the dangers of the Atkins diet. Because of the severe restriction of carbohydrates, a person will lack fiber, which can cause gastrointestinal problems like constipation. Also, the high protein diet is high in cholesterol and saturated fat. This can lead to heart disease, kidney damage and possibly some cancers, Dr. Norwood warns. Because you are depleting the body’s primary source of energy, carbohydrates, the person will feel fatigued and incur a loss of energy. The Atkins diet also does not promote learning about portion co
ntrol or serving sizes, so the person does not develop any healthy eating habits.

Again, the use of "healthy" in reference to eating habits...

Shortly after I started the Atkins Diet, I visited my physician for a baseline blood test. He warned me that such a diet was not a good idea, but agreed to order blood tests every couple of months. After two weeks on the diet, I had lost 6.5 pounds from a starting weight of 213.5 pounds. My friends were warning me that this was just a loss in water weight. However, I was starting to feel better then ever. My chronic insomnia, which goes back as far as I can remember, disappeared as did my weekly migraine headaches. My chronic heartburn also subsided. Oddly, I felt more energetic and less hungry throughout the day. By day 161, I was down to 174 pounds. At a height of 6'1" I was becoming concerned that my weight was dropping too quickly - about 0.25 pounds per day; so, I started to increase my carbohydrate intake and my weight stabilized, then began to increase a tad.

The only change in my life at that time was my diet. My exercise regimen remained constant as did my stress on the job and my satisfaction with family life, etc. Of course, my story up to this point is a worthless testimonial without hard data. When I started the diet, my physician informed me that the best indicator of risk factor was the ratio of bad cholesterol to good cholesterol, so I used that as a metric.

Above and to the right is a plot of my weight (red points) and the risk factor (green points) over the first six years of my diet. I used an electronic bathroom scale that is accurate to 0.1 pound and took my weight every morning at the same time within about a 30 minute variation.

The smooth blue curve is a plot of a model that is a sum of two exponentials. An exponential function usually is a good model of the time dependence of a process that is the result of a single rate, in this case my weight drop. However, because I changed to a diet with higher carbohydrate content about 3 months later, this introduces a second rate - thus a sum of the two exponentials. The purpose of the model is solely to provide a rough mathematical estimate of the data, which happens to reproduce its shape pretty well.

My diet was heavily skewed in favor of fat. Breakfast consisted of eggs with lots of cheese, and sometimes bacon on the side or pieces of salami mixed in with the eggs for a little extra flavor. Lunch consisted of a small amount of green salad with lots of meat and cheese and a mayonaise-based dressing with no carbohydrates. Dinner was steak, chicken, or a burger smothered in cheese but no buns; my diet was heavily skewed towards red meat. Later in my diet, I added string beans as a side dish. When having lunch with my children at McDonald's, I would order 4 double cheeseburgers minus the bus. At Pizza hut, I would eat a whole pizza without the dough (served on the metal pan), with extra cheese, of course. I even ordered doughless pizza in Korea, were it took a conference of all the employees to determine if it was possible.

During the diet, I took mega vitamins to make sure that I was not missing the essentials.

My experiment was designed to test the two hypotheses originally proposed by Atkins: low carbohydrate diets lead to weight loss and lowered cholesterol. The plot of the data clearly shows my weight loss, which I kept off for almost a decade. Throughout this time, my cholesterol risk factor oscillated in a good range of 3 to 5 (correlated with my carb intake).

In the long run, the diet was difficult to maintain not because it was unpleasant to me, but because of protests from my wife (she loves culinary variety); and, the difficulty of finding low carbohydrate dishes at restaurants or as dinner guests of our friends. I first strayed from the diet by casual cheating at such outings. Interestingly, my largest weight gain started in the summer of 2o05 while in Belgium, where our only form of transportation was walking and biking. Furthermore, we ate "healthy" European foods that included wonderful bread, fruits and vegetables. My weight increased, as did my cholesterol.

I totally gave up on the diet from that point on because it was impossible to maintain in my travels; and, it was difficult to maintain due to social pressures. I was thought weird and inconsiderate for having such a strange diet. It would be wonderful if one could get a low carb meal with the same kind of respectful deference as is given to vegetarians.

My sample-of-one-subject experiment is not necessarily representative of the general population. However, having a Sheldonesque obsessive compulsive personality, my experiment was probably better controlled than is possible in a large population. During the time period shown in the plot, I carefully nionitored my carb intake, slowly adding carbs as my weight stabilized at my target value.

Later, scientifically controlled studies found the same result, as is described below. Note how my data is very similar to the low carb plot, and how the weight loss is faster and cholesterol control better in the low carb diet compared with the low calorie diet that is typically considered healthy.

Below is a verbatim summary of the article, "Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet," which appeared in The New England Journal of Medicine 2008; 359:229-241, July 17, 2008.


In this 2-year trial, we randomly assigned 322 moderately obese subjects (mean age, 52 years; mean body-mass index [the weight in kilograms divided by the square of the height in meters], 31; male sex, 86%) to one of three diets: low-fat, restricted-calorie; Mediterranean, restricted-calorie; or low-carbohydrate, non–restricted-calorie.


The rate of adherence to a study diet was 95.4% at 1 year and 84.6% at 2 years. The Mediterranean-diet group consumed the largest amounts of dietary fiber and had the highest ratio of monounsaturated to saturated fat (P<0.05 p="0.01)." style="font-weight: bold;">Conclusions

Mediterranean and low-carbohydrate diets may be effective alternatives to low-fat diets. The more favorable effects on lipids (with the low-carbohydrate diet) and on glycemic control (with the Mediterranean diet) suggest that personal preferences and metabolic considerations might inform individualized tailoring of dietary interventions. ( number, NCT00160108.)

Given the evidence, I am greatly annoyed that people still consider fat unhealthy. There are no documented adverse affects of a high fat diet when carbs are removed. It is mostly hearsay and pontification of supposed experts. I am once again trying to stick with a low carb regimen. Perhaps it is futile, but I have already lost 5 pounds in less than two weeks. The real test of my resolve will be the short trip we are taking to the west side. I hope that I will still be eating "healthy" when we return.

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