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2004/04/26, 12:34 PM
Glycemic Index (GI) isn’t a new term. But as the low-carb craze rages on, those who sat closer to the sensible side of the fence used GI as an indicator to separate "good carbs" from "bad carbs." The GI of a food is a ranking or a measure based on the food’s impact upon blood glucose levels. Glycemic Index estimates how dramatically blood sugar increases over a period of two or three hours after consuming the food in question. Carbohydrate foods that break down into glucose rapidly will have the highest Glycemic Index. If we understand that insulin spikes can limit fat release, we’ll also recognize that blood sugar spikes are not warranted if fat loss is the goal at hand. At first glance, it would therefore make sense that the GI of a food would measure whether or not it is "fat loss friendly." Here’s where it gets a bit confusing. The GI of a potato is over 80, yet the GI of ice cream is slightly over 50. That would mean ice cream is more "fat loss friendly" than potato? That doesn’t quite make sense, does it? With its high fat content combined with high sugar content, how could ice cream be more of a fat loss aid than a natural complex carb loaded with essential vitamins and minerals? Let’s go back to the definition of Glycemic Index. Glycemic Index estimates how dramatically blood sugar increases after consuming a food... by itself! Of course if you consume a potato without anything else, the glucose molecules, linked together in chains, are very efficiently dissolved resulting in a rush of glucose into the blood stream. Add butter, sour cream, and bacon to the potato and guess what happens to the glycemic index? It drops significantly. The fat and protein work to slow the breaking apart of the glucose chains, and that potato becomes more of a “slow release” carbohydrate. If you’re looking to lose fat, I’m not suggesting you load up your potato with fat, but I am suggesting that if you consume the potato with a chicken breast and a serving of mixed vegetables, the concept of GI is irrelevant. It no longer applies. Because, if we are seeking optimal health and well being, we want to consume nutrient efficient meals, we should consume our complex carbs (starches) in the presence of protein and fiber. Ingesting a lean protein, starchy carb, and fibrous carb from natural unrefined sources can actually work to stabilize blood sugar by allowing for a gradual release of glucose which serves to meet energy needs. You never get the blood sugar spike, thus insulin production remains moderate and constant. This makes for an optimal fat burning state.
Thermogenic is a term that’s been used for almost a decade to sell products labeled as "fat burners." The word has been equated in marketing with the idea of near miraculous fat burning. The prefix thermo actually relates to "heat." Genic, from the word Genesis, means "beginning." Thermogenic, therefore, means, "initiating heat." There are some compounds, such as the recently scrutinized ephedrine and other stimulants such as yohimbe and L-tyrosine that, when ingested, can result in a body temperature elevation. Because metabolism is actually the "burning" of fuel and efficient production of energy and heat, there is a correlation between body temperature and metabolism, but "initiating heat" in the short term is not necessarily a fat loss guarantee, nor is it necessarily safe. If you were to sit in a sauna for 15 minutes, you’d be stimulating a thermogenic effect, but I’m sure you’ve heard of the risks associated with extreme manipulation of temperature increases. Exercising is thermogenic. Eating spicy foods can be thermogenic. There’s nothing magical about a "thermogenic" supplement.
Unfortunately, most of the supplements sold to "initiate heat" work as stimulants. They may constrict arteries, thus the heart has to beat faster to deliver required blood flow. They may elevate blood pressure. They may also have a diuretic effect. Worst of all, these compounds are often addictive, so the thermogenic lure often leads to potentially hazardous addiction. Before you start buying products because they use big words to pretend to contain some miraculous properties, investigate the ingredients, and understand the risks. In more cases than not you’ll find the big words serve only to confuse, and of course, sell products via unrealistic hype of unrealistic results.
Prohormone is a word used to sell products aimed both at the muscle wanting population and men seeking youth preservation and virility. You’re probably familiar with the word "hormone." A hormone is a chemical structure that is carried in the bloodstream in order to stimulate a part of the body to act. Hormones are, in essence, chemical messengers that stimulate processes of growth, energy, metabolism, and protection. The primary male hormone, the chemical most responsible for those characteristics associated with men, is testosterone. Testosterone can be injected directly into the body in synthetic form (anabolic steroids), but naturally it is manufactured from other hormones. The hormonal cascade actually begins with cholesterol and via a series of metabolic and chemical actions, cholesterol is converted into DHEA. DHEA is the raw material for testosterone, but there are many links in the chain during the conversion process. Those "links" would be considered testosterone precursors. The term "Prohormone" is a marketing term that suggests there is something wonderful about these oral hormonal precursors. The idea is if you ingest something that ultimately converts to testosterone, you ultimately increase testosterone levels. Prohormones have names like androstenedione and androstenediol, and then, to complicate matters, these compounds often have prefixes or numbers tagged on. The ads tout the muscle building properties of 19-norandrostenediol. The number refers to the molecular position of a hydrogen or carbon atom which, in part, is how the hormonal conversion takes place. Add a hydrogen molecule to the 17th position of an androstenedione molecule (which is precisely what the liver does to make testosterone) and you’ve created testosterone. Confusing? Of course it is. It’s molecular biochemistry. Unless you are a molecular biochemist, you’re going to be confused by all of the prohormone offerings, and in that confusion lies the marketing success of these products. If they do in fact increase testosterone, then you are interrupting the hormonal cascade, and there can be unanticipated alterations in estrogen production, in leutenizing hormone production, in follicle stimulating hormone production, etc. Interrupt the hormonal cascade randomly and you run the risk of both short and long-term side effects ranging from liver issues to sexual dysfunction. If these products do "work," then they come with the side effects of anabolic steroids, and if they are "safe," well... quite simply, they don’t “work.” Because the reality behind the prohormones is often lost in the scientific double talk, people become unwilling victims of unscrupulous marketers. If you are going to experiment with endocrine manipulation, I’d encourage you to get a full hormonal assay done in a laboratory, have the results reviewed by an endocrinologist, and decide, together with the assistance of a medical professional, what the best course of hormonal therapy would be. -Phil Kaplan-
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