Excess iodine has symptoms similar to those of iodine deficiency. Commonly encountered symptoms are abnormal growth of the thyroid gland and disorders in functioning and growth of the organism as a whole. Elemental iodine, I2, is a deadly poison if taken in larger amounts; if 2–3 grams of it are consumed, it is fatal to humans. Iodides are similar in toxicity to bromides.
Such studies often do not test calcium alone, but rather combinations of calcium and vitamin D. Randomized controlled trials found both positive[26][27] and negative[28][29][30][31] effects. The different results may be explained by doses of calcium and underlying rates of calcium supplementation in the control groups.[32] However, it is clear that increasing the intake of calcium promotes deposition of calcium in the bones, where it is of more benefit in preventing the compression fractures resulting from the osteoporotic thinning of the dendritic web of the bodies of the vertebrae, than it is at preventing the more serious cortical bone fractures which happen at hip and wrist.
For determination of boron content in food or materials the colorimetric curcumin method is used. Boron has to be transferred to boric acid or borates and on reaction with curcumin in acidic solution a red colored boron-chelate complex, rosocyanine, is formed.
Brown amorphous boron is a product of certain chemical reactions. It contains boron atoms randomly bonded to each other without long range order.
Crystalline boron, a very hard, black material with a high melting point, exists in many polymorphs. Two rhombohedral forms, ?-boron and ?-boron containing 12 and 106.7 atoms in the rhombohedral unit cell respectively, and 50-atom tetragonal boron are the three most characterised crystalline forms.
Optical characteristics of crystalline/elemental boron include the transmittance of infrared light. At standard temperatures, elemental boron is a poor electrical conductor, but is a good electrical conductor at high temperatures.
Chemically boron is electron-deficient, possessing a vacant p-orbital. It is an electrophile. Compounds of boron often behave as Lewis acids, readily bonding with electron-rich substances to compensate for boron’s electron deficiency. The reactions of boron are dominated by such requirement for electrons. Also, boron is the least electronegative non-metal, meaning that it is usually oxidized (loses electrons) in reactions.
Boron is also similar to carbon with its capability to form stable covalently bonded molecular networks. Boron is also used for heat resistant alloys. Boron can form compounds whose formal oxidation state is not three, such as B(II) in B2F4.[4] Introduction to Boron: History, Sources, Uses, and Chemistry | first = Berzelius]] in 1824 who identified boron as an element. The first pure boron was produced by the American chemist W. Weintraub in 1909, although this is disputed by some researchers.[5] [6]
There is a substantial market for products which promise to make weight loss easier, quicker, cheaper, more reliable, or less painful. These include books, CDs, cremes, lotions, pills, rings and earrings, body wraps, body belts and other materials, not to mention fitness centers, personal coaches, weight loss groups, and food products and supplements. US residents in 1992 spent an estimated $30 billion a year on all types of diet programs and products, including diet foods and drinks.[9]
Between $33 billion and $55 billion is spent annually on weight loss products and services, including medical procedures and pharmaceuticals, with weight loss centers garnering between 6 percent and 12 percent of total annual expenditure. About 70 percent of Americans’ dieting attempts are of a self-help nature. Although often short-lived, these diet fads are a positive trend for this sector as Americans ultimately turn to professionals to help them meet their weight loss goals [10].
A crash diet is where a person willfully restricts themselves of all nourishment (except water) for more than 12 hours. The desired result is to have the body burn fat for energy with the goal of losing a significant amount of weight in a short time. Crash dieting is not the same as intermittent fasting, in which the individual periodically abstains from food (e.g., every other day).
The least intrusive weight loss methods, and those most often recommended by physicians, are adjustments to eating patterns and increased physical exercise. Physicians will usually recommend that their overweight patients combine a reduction of the caloric content of the diet with an increase in physical activity.[7]
Other methods of losing weight include use of drugs and supplements that decrease appetite, block fat absorption, or reduce stomach volume. Medicines with herbs such as Fucus vesiculosus are popular [8].Finally, surgery may be used in more severe cases. Bariatric surgery artificially reduces the size of the stomach, limiting the intake of food energy.
Weight loss refers to the loss of total body mass in an effort to improve fitness, health, and/or appearance.
Therapeutic weight loss, in individuals who are overweight or obese, can decrease the likelihood of developing diseases such as diabetes[4], heart disease, high blood pressure, stroke, osteoarthritis[5], and certain types of cancer.
Weight loss occurs when an individual is in a state of negative energy balance. When the human body is spending more energy in work and heat than it is gaining from food or other nutritional supplements, it will use stored reserves of fat or muscle.
It is not uncommon for some people who are currently at their ideal body weight to seek additional weight loss in order to improve athletic performance, and/or meet required weight classification for participation in a sport. However, others may be driven by achieving a more attractive body image. Consequently, being underweight is associated with health risks such as difficulty fighting off infection, osteoporosis, decreased muscle strength, trouble regulating body temperature and even increased risk of death.[6]
Poor management of type 1 diabetes mellitus, also known as insulin-dependent diabetes mellitus (IDDM), leads to an excessive amount of glucose and an insufficient amount of insulin in the bloodstream. This triggers the release of triglycerides from adipose (fat) tissue and catabolism (breakdown) of amino acids in muscle tissue. This results in a loss of both fat and lean mass, leading to a significant reduction in total body weight. Note that untreated type 1 diabetes mellitus will usually not produce weight loss, as these patients get acutely ill before they would have had time to lose weight.
Myriad additional scientific considerations are applicable to weight loss, including but not limited to: physiological and exercise sciences, nutrition science, behavioral sciences, and other sciences.
One area involves the science of bioenergetics including biochemical and physiological energy production and utilization systems, that is frequently evidence of diabetes, and ketone bodies, acetone particles occurring in body fluids and tissues involved in acidosis, also known as ketosis, somewhat common in severe diabetes.
In addition to weight loss due to a reduction in fat and lean mass, illnesses such as diabetes, certain medications, lack of fluid intake and other factors can trigger fluid loss. And fluid loss in addition to a reduction in fat and lean mass exacerbates the risk for cachexia.
Infections such as HIV may alter metabolism, leading to weight loss.[1]
Hormonal disruptions, such as an overactive thyroid (hyperthyroidism), may also exhibit as weight loss.[2]
Recent research has shown fidgeting to result in significant weight loss. [3]
Weight loss, in the context of medicine or health or physical fitness, is a reduction of the total body weight, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue.