Carbohydrates, Fats and Calories
We need them all, but how much and in what ratios and forms?
Nutrition is an extremely-complex highly-controversial set of intricately interrelated and interdependent scientific, physiological and psychological topics. There are very-intelligent highly-qualified board-certified “experts” with good and valid arguments and contradictory viewpoints on mutually exclusive positions that cannot possibly both be true. Some authorities and government agencies have recently admitted publicly that what they said ten to twenty years ago has been scientifically proven to be detrimental to public health.
When this happens (as it often does in multifaceted scientific research) we sometimes assume that the subject is more like controversial politics, pure faith or ancient religious opinions, rather than something based on any knowable absolute scientific truths.
The USDA (source of the admittedly-obsolete and ineffective 1992 Food Pyramid) hosted the Great Nutrition Debate, with diet specialists including Dr. (Low Carb) Robert Atkins, Dr. (Low Fat) Dean Ornish, and “experts” from the American Dietetic Association (ADA). They argued over: “What is the best diet for weight loss?” (The ever-increasing unprecedented recent American morbid-obesity epidemic)
It was impossible to reach consensus between the
highly-biased, deeply-entrenched opposite ends of the opinion spectrum. The
only absolute truth that did come out very loud and clear is that
there is no single “best” diet for everyone.
Each of us must discover lifestyle choices that work for us. The choices we make can have a dramatic impact on our rate of aging. The problem that this process of trial and error, frequent failure and frustration often takes many people decades. And, to make the lengthy process even more complex, our nutrition needs change with every year of our life, and even with every physical activity we engage in. For example, infants and active children need far more carbohydrates than sedentary adults.
Changing long-held traditional eating habits is extremely difficult. The massive mediocre majority frequently says: “I know I shouldn’t eat this, but I’m going to (damage my health, happiness and longevity) anyway.”
Several important new federal research studies are currently underway comparing the long-term impact of Low Carbohydrate versus Low Fat versus Low Calorie diet plans. It is becoming clear that a recent move toward recommended low-fat diets and a resulting rise in carbohydrate intake is strongly statistically and epidemiologically linked to the increased incidence of American obesity.
U.S. government agencies have recently become aware that their inaccurate, incomplete advice and recommendations are at least partially responsible for the recent American morbid obesity epidemic.
Consider the following recent research finding, which is motivating important changes in the obsolete 1992 Food Pyramid, etc. In fact the entire concept of the Food Pyramid (based on undifferentiated foods within broad categories is itself overly simplistic, misleading and highly flawed, since for example, some manufactured dietary fats are deadly and some we cannot live without. Some carbohydrate foods significantly reduce aging processes, and some carbs make us get fat and die early.
- - - - - High Glycemic Index Foods That Replace Dietary Fats Trigger Overeating - - - - -
Have you ever wondered why you often feel hungry a few hours after eating a big meal? Chances are you ate low-fat carbohydrate-containing foods that caused a rapid spike in your blood sugar. Your body responds by releasing extra insulin into your blood stream. Excess blood sugar is converted into stored body fats. The high insulin makes blood sugar crash back down and suppresses burning fats as well - You feel famished, which leads to overeating, shortly after eating a large meal.
That is what happened in a study of obese teenage boys by researchers at Children's Hospital in Boston and also at the USDA center in Boston. It was the first solid scientific evidence that carbohydrates with a high glycemic index (those that are rapidly digested and quickly release glucose into the blood stream) contribute to obesity.
On separate days at least a week apart, researchers fed the boys breakfast and lunch having a high, medium or low glycemic index (GI). The boys ate almost twice as much after the high-GI meals compared to the low-GI meals. The high-GI meals induced a sequence of hormonal and metabolic changes that promoted overeating. http://www.pediatrics.org/cgi/content/full/103/3/e26:
Results: Voluntary energy intake after the high-GI meal (5.8 megajoule [mJ]) was 53% greater than after the medium-GI meal (3.8 mJ), and 81% greater than after the low-GI meal (3.2 mJ). In addition, compared with the low-GI meal, the high-GI meal resulted in higher serum insulin levels, lower plasma glucagon levels, lower post absorptive plasma glucose and serum fatty acids levels, and elevation in plasma epinephrine.
Conclusions. The rapid absorption of glucose after consumption of high-GI meals induces a sequence of hormonal and metabolic changes that promote excessive food intake in obese subjects. Additional studies are needed to examine the relationship between dietary GI and long-term body weight regulation.
Excessive fat consumption is widely believed to be a major dietary cause of obesity. For this reason, the US Department of Health and Human Services, American Heart Association, and American Diabetes Association currently advocate consumption of a low-fat diet in the prevention and treatment of obesity. Recently, however, the relationship between dietary fat and obesity has been questioned on several grounds including that both cross-sectional and longitudinal analyses have failed to show a consistent association between dietary fat and body fat, and that weight loss on low-fat diets is usually modest and transient. In addition, and perhaps of particular significance, mean fat intake in the United States reportedly has decreased over the past 3 decades, from 42% to 34% of dietary energy, whereas the rate of obesity has continued to rise.
Another dietary factor that influences body weight is the glycemic index (GI). GI is a property of food that describes the rise of blood glucose occurring after a meal. Foods that are rapidly digested and absorbed or transformed metabolically into glucose have a high GI. The GI of a food or meal is determined primarily by the amount of carbohydrate consumed and by other dietary factors affecting food digestibility, gastrointestinal motility, or insulin secretion (including carbohydrate type, food structure, fiber, protein, and fat). Sugars and starchy foods commonly eaten in North America, chiefly refined grain products and potatoes, have a high GI, exceeding that of even table sugar by up to 50%. In contrast, vegetables, nuts, legumes, and fruits generally have a lower GI.
A potential adverse consequence of the decrease observed in mean fat intake in recent years is a concomitant increase in dietary GI. A reduction of dietary fat tends to cause a compensatory increase in sugar and starch intake. Indeed, a rise in total carbohydrate consumption since the 1970s has been documented. Furthermore, because fat slows gastric emptying, carbohydrate absorption from low-fat meals may be accelerated. In view of these observations, it seems likely that the GI of the American diet has risen in recent years. Previously, an inverse relationship between GI and satiety has been shown in several single-meal studies. Although these reports suggest a potential influence of GI on short-term energy intake, the practical relevance of GI to energy regulation and obesity remains unclear.
The purpose of this investigation was to test the hypothesis that consumption of high-GI foods induces a sequence of hormonal changes that lead to decreased availability of metabolic fuels, excessive hunger, and overeating in obese subjects.
The researchers believe that their findings apply to the middle-aged and elderly as well. An alarming number of U.S. children and adults are now significantly overweight, following a reduction in fat intake since food labels were required to show fat content, and the 1992 USDA Food Pyramid low-fat, high-carbohydrate diet was recommended.
Humans are omnivores – our systems can adapt to eating meat or certain types of vegetables, in the correct natural forms and proportions. Clearly, the above study points out that a low-fat, high-carbohydrate diet can be very unhealthy for a significant portion of our population.
The location of our two eyes in the front of our head (necessary for stereoscopic vision used kill fast-moving prey) makes it clear that early humans originally evolved as meat-eating carnivores. (Herbivores have eyes on the sides of their head, as a defense mechanism. Humans do not.) There is no medical reason for most humans to avoid eating natural healthy meat (although there are many good health reasons to avoid certain types of commercially raised and processed meats, contaminated and diseased meats).
You may have respectable religious and moral beliefs that prevent you from eating animal products, but if so, you have to be especially careful to consume the correct mix of vegetable products, and avoid or restrict items with a high glycemic index. When I visited Asia in the new millenium, I found that strict Buddhist vegans were wisely instructed to eat 7 almonds per day, etc. Strict vegans attempt to avoid the use all animal products, such as skins, furs, leather, etc. Even most modern synthetic fibers, plastics, automobile parts, fuel, highways and houses, contain animal products, since petroleum is long-dead animal (sea creature) fat that has been compressed and aged over geologic time. Natural organic vegetables are fertilized with animal excrements, containing animal cells. It is extremely difficult (impossible) to avoid animal products altogether.
Human DNA, biological metabolic mitochondria, enzymes, and cellular / tissue / organ systems evolved to effectively metabolize fresh natural healthy meats, and natural vegetables found in our natural environment, including the normal levels of fats and nutrients found therein. However, human internal systems can NOT deal well with modern highly-processed, unnatural, manufactured foods and food preparation methods, such as trans fatty acids found in fried foods, margarine, shortening, salad dressings, commercially baked goods (bread, cookies, cake, pie, pizza, etc.). Unnatural high-temperature cooking, frying and grilling (above 300 degrees Fahrenheit) produces a variety of well-known cancer-causing substances. Natural “antioxidants” found in many healthy foods can reduce the impact of our polluted environment and unnatural processed foods.
Lifestyle choices of nutrition, exercise and attitude have dramatic impacts on our health and happiness.
(This important web page is under active construction – Check back in a few weeks)