Increasingly, products called "thermogenics" are being created that are intended to reduce body weight and excess fat. Today we want to examine whether these thermogenic supplements have any contraindications or side effects and, if so, to understand what kind.
First, it is important to remember how energy expenditure occurs, which includes basal metabolism, physical activity, and thermogenesis. This will allow us to understand why these products arose in the supplement market.
Basal metabolism we have talked about before, it is in a nutshell the energy we consume at rest. Basal metabolic rate depends on genetic, nutritional, and metabolic factors and varies with an individual's sex, age, height, and weight.
Physical activity is another factor that causes energy "consumption"; it varies with the intensity and duration of the exercise or work we are going to do, as well as the frequency.
Thermogenesis, on the other hand, is determined by the thermal effect of food and accounts for about 15 percent of energy expenditure. In fact, food intake produces 'heat' in excess of basal metabolism. It is affected by food intake, cold exposure, stress, and thermogenic substances and hormones.
A mixed diet can increase the consumption of calories expended for heat gain by 6-10% over baseline (Rosenberg, 1994).
It has been found that some foods can cause greater thermogenesis than others: the greatest stimulus comes from protein and amino acids (10-35% of ingested energy), while lower values are attributed to carbohydrates and lipids. Hence it can be understood why many protein-based diets are so popular, not just useful for the development of lean mass (muscle) as is often believed.
The so-called thermogenics on the market include several categories of products: they are based on stimulants that can increase metabolism (caffeine, ginseng, synephrine, guarana, iodine etc.), proteins, purgatives and dietary fiber, which reduce nutrient absorption, increase intestinal motility, stool production and create a sense of satiety that influences the amount of food we go to eat during the day.
Just recently, the European Community authorized 'claims' on certain fibers after reviewing several related scientific studies that demonstrated their effectiveness. The same cannot yet be said about other substances.
Thermogenic supplements are found in tablets or pills, capsules, tablets and powders.
They are generally well tolerated at prescribed doses however some possible contraindications or side effects at higher doses should be kept in mind:
- Iodine is not suitable for hyperthyroid subjects as it can accentuate a state of thyrotoxicosis with phenomena such as tremors, tachycardia, and insomnia.
- Caffeine and extracts containing it such as guarana and kola raise heart rate; synephrine and ginseng also raise blood pressure. Therefore, these substances should be taken in consultation with one's doctor first, especially in the case of elderly or heart patients.
- Protein involves more work in the liver and kidneys in relation to the amount taken with a significant increase in nitrogen catabolites. Therefore subjects with hepatopathy or renal insufficiency should reduce the amount while still consulting the doctor.
- Fiber increases intestinal work (peristalsis) and therefore should be taken with caution in the presence of inflammatory processes such as colitis and Crohn's disease. They should also be taken with plenty of water to avoid difficulty swallowing particularly in individuals with dysphagia.
- Herbal teas based on plant extracts such as those of senna, rhubarb, frangula, cassia and others have a true purgative and possibly dehydrating action. In addition, if used frequently they can give rise to addiction resulting in constipation as soon as intake ceases. Finally, they are clearly contraindicated in those engaged in intense physical activity.
A separate note deserves ephedrine or Ma Huang, a currently banned thermogenic and doping substance, found until a few years ago mainly in American products, linked to cases of stroke and even fatal cardiac arrhythmias.
First, it is important to remember how energy expenditure occurs, which includes basal metabolism, physical activity, and thermogenesis. This will allow us to understand why these products arose in the supplement market.
Basal metabolism we have talked about before, it is in a nutshell the energy we consume at rest. Basal metabolic rate depends on genetic, nutritional, and metabolic factors and varies with an individual's sex, age, height, and weight.
Physical activity is another factor that causes energy "consumption"; it varies with the intensity and duration of the exercise or work we are going to do, as well as the frequency.
Thermogenesis, on the other hand, is determined by the thermal effect of food and accounts for about 15 percent of energy expenditure. In fact, food intake produces 'heat' in excess of basal metabolism. It is affected by food intake, cold exposure, stress, and thermogenic substances and hormones.
A mixed diet can increase the consumption of calories expended for heat gain by 6-10% over baseline (Rosenberg, 1994).
It has been found that some foods can cause greater thermogenesis than others: the greatest stimulus comes from protein and amino acids (10-35% of ingested energy), while lower values are attributed to carbohydrates and lipids. Hence it can be understood why many protein-based diets are so popular, not just useful for the development of lean mass (muscle) as is often believed.
The so-called thermogenics on the market include several categories of products: they are based on stimulants that can increase metabolism (caffeine, ginseng, synephrine, guarana, iodine etc.), proteins, purgatives and dietary fiber, which reduce nutrient absorption, increase intestinal motility, stool production and create a sense of satiety that influences the amount of food we go to eat during the day.
Just recently, the European Community authorized 'claims' on certain fibers after reviewing several related scientific studies that demonstrated their effectiveness. The same cannot yet be said about other substances.
Thermogenic supplements are found in tablets or pills, capsules, tablets and powders.
They are generally well tolerated at prescribed doses however some possible contraindications or side effects at higher doses should be kept in mind:
- Iodine is not suitable for hyperthyroid subjects as it can accentuate a state of thyrotoxicosis with phenomena such as tremors, tachycardia, and insomnia.
- Caffeine and extracts containing it such as guarana and kola raise heart rate; synephrine and ginseng also raise blood pressure. Therefore, these substances should be taken in consultation with one's doctor first, especially in the case of elderly or heart patients.
- Protein involves more work in the liver and kidneys in relation to the amount taken with a significant increase in nitrogen catabolites. Therefore subjects with hepatopathy or renal insufficiency should reduce the amount while still consulting the doctor.
- Fiber increases intestinal work (peristalsis) and therefore should be taken with caution in the presence of inflammatory processes such as colitis and Crohn's disease. They should also be taken with plenty of water to avoid difficulty swallowing particularly in individuals with dysphagia.
- Herbal teas based on plant extracts such as those of senna, rhubarb, frangula, cassia and others have a true purgative and possibly dehydrating action. In addition, if used frequently they can give rise to addiction resulting in constipation as soon as intake ceases. Finally, they are clearly contraindicated in those engaged in intense physical activity.
A separate note deserves ephedrine or Ma Huang, a currently banned thermogenic and doping substance, found until a few years ago mainly in American products, linked to cases of stroke and even fatal cardiac arrhythmias.
RELATED PRODUCTS