There is a huge amount of misinformation being taught in the raw food world about metabolism. This is quite understandable, as most people do not even truly understand what their metabolism is. Some folks are teaching that the rate of your metabolism determines just exactly which foods are best suited for you to eat. They teach that people are born as either fast or slow metabolizers, and glorify the advantages of being a fast metabolizer. They assert that the fast metabolizers burn through fuel more rapidly than the slow metabolizers, making the fast metabolizers relatively more efficient at digesting their food. Actually, the opposite is really true. It is easy to understand if we use a car analogy. The car that gets more miles to the gallon is more efficient than the car that gets fewer miles to the gallon. It is equally as easy to understand that the person who utilizes the least fuel to accomplish any particular task, i.e., the slow metabolizer, is the most efficient.
Many raw food teachers currently say that if you are a fast metabolizer you must eat in a certain way, that is, to skew your diet so that fats (nuts, seeds, oils, avocados, olives, etc.) make up an exceptionally high percentage of total calories (60-80%). If you do not, they teach, you are destined to fail as a raw fooder. They also say that if you are a slow metabolizer that you may possibly do better to slightly increase your consumption of fruits, but that fruit (due to their abundant simple carbohydrates) should still be minimized in the overall diet.
The fast metabolizers, it is taught, will only thrive on a high fat diet, as fruits will prove to be insufficient in terms of fuel density, leaving the consumer constantly hungry and suffering from the maladies (mistakenly) associated with the overconsumption of fruit's sugars. Only the slowest metabolizers, it is taught, could even hope to have a chance at possibly succeeding, healthwise, by utilizing fruit for fuel. Often, athletes are brought into the example. If you are a serious athlete, then you might be able to use more fruit if you are a very slow metabolizer, it is said, but otherwise, it is too easy to overeat on fruit and it really should simply be avoided.
First, let's begin with a few terms. The term metabolism represents the sum of all of the catabolic and anabolic processes that go on within your body. The anabolic activities in your body are those whereby simpler structures are united to form more complex ones. Anabolism represents the building processes in your body: growth, repair, and all of the recombinant chemistry that goes on at the cellular and visceral level. Catabolic activities are those whereby complex structures are broken down into simpler ones. Digestion, osteoclastic activity (cells that break down bones), and the conversion of glycogen to glucose are examples of catabolism in action. Metabolism is not, in and of itself, a single function, but rather a representation of the sum total of anabolism and catabolism that is going on in the body at any given time.
Author's note: It is the impression of this writer that slow in the sense it is used by most raw food teachers seems also to be associated with negative themes such as uncoolness and mental slowness. The imagery used in association with fast metabolizers is sexy and fun, as in; fast cars and fast blondes.
Physical activity, or lack of it, determines metabolic rate
The term metabolism does have a useful meaning for us, however. We use it with reference to the phrase, basal metabolic rate, or BMR. We use the two terms almost but not quite as synonyms. The basal metabolic rate is a measure of the amount of fuel a person utilizes, per unit of time, when awake and totally at rest. It does not include such functions as physical activity, daily household chores, or even digestion. When we use the word, metabolism we use it to mean BMR plus all the activities of the day. We might say, He has a fast metabolism and she has a very slow metabolism. By this we would mean that a person with a fast metabolism requires more fuel to perform the same amount of anabolic and catabolic processes as the person with a slow metabolism. This makes the fast metabolizer less efficient in their use of fuel. Either way, however, the difference is not very much, as the BMR rarely varies much more than about plus or minus 5% from person to person of similar body size and design. Body surface area, it turns out, is the biggest factor affecting BMR. BRM in humans accounts for the use of around 1000 calories per day.
What does affect fuel use is the amount of physical exertion one performs. A sedentary person may only use 200 calories per day in performing their daily functions whereas someone going for a vigorous 4-hour hike could use 2000 calories. Professional athletes often use 4000 calories solely for their daily training and Tour de France riders are known to use over 10,000 calories on certain days of this grueling competition. Hence it becomes easy to see that differences in BMR, or metabolism, as it is commonly referred to, plays an exceptionally small role in total calorie usage, usually representing less than 100 calories out of 2,000 to 4,000 or even more.
The truly fast metabolizer is one who uses more calories per hour, throughout the day, than the average person does. The more calories one utilizes in the course of the day, the faster would be their total metabolism. It can safely be said that a fit woman of average physique uses about 1800 calories per day and the average-sized fit man about 2400. Using the man for this example, it would mean that he averages about 100 calories per hour. We could therefore assert that a man who uses more than 100 calories per hour would be termed a fast metabolizer and a man who uses less than 100 calories per hour would be a slow metabolizer.
How Much Fat is Optimum?
The concept that fast metabolizers must consume more fat per calorie than slow metabolizers has been taught as fact in raw food circles for many years. This is contrary, however, to all we know about human health and nutrition. The Director of Nutrition for the United States Olympic Teams says, the amount of fat (as a percentage of total calories) required for the athlete remains the same, regardless of sport. The only thing that varies, sport by sport and athlete by athlete, she asserts, is the total number of calories required. Vegan doctors McDougall, Pritikin, Ornish, Campbell, Klaper, Harris, Heidrich, Barnard, and many others, all internationally renowned for their forward stance on nutrition are in agreement that 10% of calories from fat is the outside, high-end acceptable human limit.
In the field of raw nutrition, it is generally agreed that foods consumed in their raw state provide a greater amount of viable nutrients as well as nutrients that are more accessible, hence less food is needed than when one consumes cooked foods. This should mean, therefore, that less total fat is required to fill the essential physiologic roles it plays when we consume our foods in the raw. Why then are raw fooders told to eat more fats The excessive consumption of fat(cooked or raw) has been incontrovertibly linked to the development of cancer, heart disease, and diabetes. The more fat we consume, the higher the rates of these dread conditions. It has been shown that when we consume more fats than we require we almost invariably consume less carbohydrates than we require. Insufficient carbohydrate consumption will result in feelings of fatigue, loss of strength, and a general lowering of vigor and vitality.
Mind bending contradictions
At this point we have come to an unbridgeable contradiction. Fast metabolizers, those who utilize the most fuel per hour, are supposedly the very people who will thrive on the highest fat levels in their diet. While we are being told that only athletes can get away with the high carbohydrate (fruit-based) diet, we know that athletes are the very people who have the fastest metabolisms. Meanwhile, scientific research unwaveringly asserts that the more fat you consume the worse it will be for your health.
Small cows eat small amounts of food relative to large cows. Active cows eat more food than their sedentary counterparts, yet all cows eat primarily the same food. Fruits and vegetables have been touted as the ultimate health foods for humans for over a century, and have been the primary food of humankind throughout our existance. Whether you are small or large, active or sedentary, fruits and vegetables remain as the foods of choice for building human health. If one person needs to consume a greater quantity of calories than another person, it simply means that they must eat a greater quantity of food, not completely different foods. The Director of Nutrition for the US Olympic Team states that the relative percentages of fat, protein and carbohydrates in the athlete's diet should not vary; regardless of whether the athlete runs the mile or the marathon, lifts weights or plays table tennis, or shoots skeet or puts the shot. This author can only conclude that the low-fat, raw, vegan diet of whole, fresh, ripe, raw, organic, plants remains the best and healthiest choice for all of us.
In case that is not enough of a contradiction to try to puzzle out, work on this one. It has been repeatedly asserted that most raw fooders would do their best, healthwise, using a diet that is composed primarily of fats. This assertion is based on the assumption that most people are fast metabolizers. The Law of Averages says that as we are working with a bell curve, only about 10% of the people would be truly classed as fast metabolizers, 10% would be slow, and the rest would fall in the middle, somewhere.
Resistance to change is futile
Do not be misled by half fast metabolism mumbo jumbo. Track your fat intake on any given day and see for yourself just exactly how much of it is in your diet. There are many web sites that make such monitoring of your caloronutrient intake quite easy. I have found www.fitday.com easy to use. Its primary advantage is that you can store your records there with the option of making them available for public or private viewing. Most people are shocked and amazed to discover that their diet is upwards of 50% fat by calorie. On average, I have found that raw fooders consume approximately 65% of their calories from fat, and only 25% from carbohydrates. This in light of the fact that less than 10% fat is the recommended amount and 80+% carbohydrates is near ideal. Is it any wonder that people have trouble sticking to their all-raw diets or that they find cooked carbohydrates alluring?
What do you eat? Where do you get your protein? Don't you get tired of the lack of variety? These are the three common questions that vegetarians are asked by their Standard, Westernized Diet friends. Eventually, the vegetarians learn good answers. The same three questions are asked when we go vegan, this time, by our vegetarian friends. We eventually learn appropriate responses. Go raw, and the same questions come up again, this time from our vegan buddies. Why do they ask us these questions? The answer is simple: your friends don't want to give up their old dietary habits and so they are trying to prove you wrong. Is it any wonder that raw fooders resist switching from the high fat diet they are following to a low fat raw version? Is it any wonder that they ask the same questions' Do you have any doubt that the foot dragging is caused by deeply rooted old habits, rather than a newfound thirst for health?
Raw fats are unquestionably better for us than cooked fats, and plant fats better than animal fats. Still, the evidence is overwhelming that the high fat diet inevitably leads to many disease states including but not limited to cancer, heart disease and diabetes. Raw fooders are not immune. Do not be fooled. Fruits and vegetables are health foods. Everything else is just condiment.