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Testosterone, hormone produced by the male testis that is responsible for development of the male sex organs and masculine characteristics, including facial hair and deepening of the voice. Testosterone was isolated from testicular extracts in 1935. Its discovery followed that of an androgen (male hormone) called androsterone, which was isolated from urine in 1931. However, testosterone proved to be more potent than androsterone, which was later shown to be a biochemical product (a metabolite) of testosterone.

A healthy man produces about 5 mg (1.8 104 ounces) of testosterone daily. Testosterone serves as a circulating prohormone for a more active androgen called dihydrotestosterone. Testosterone is converted to dihydrotestosterone in most tissues that are sensitive to androgens, including the testes, prostate gland, hair follicles, and muscles. Although testosterone itself has androgenic actions, its conversion to dihydrotestosterone is critical to the development of external genitalia in boys. Testosterone is also converted to estradiol in adipose tissue (and to a lesser extent in some other tissues), which is the most important source of estrogen in men. Furthermore, testosterone is interconvertible with androstenedione, which can be converted into estrogens. When androstenedione is formed in adipose tissue, it may be converted to a form of estrogen called estrone.

Similar to other steroid hormones, testosterone exists in serum in two forms. Most testosterone in the serum is bound to sex hormone-binding globulin and to albumin, while the remaining amount (about 1 percent) is free, or unbound. Free testosterone is in equilibrium with bound testosterone so that when free testosterone enters cells, some bound testosterone is immediately freed. In the cytoplasm of target cells, testosterone or dihydrotestosterone binds to specific androgen receptors, and the hormone-receptor complexes enter the cell nucleus, where they modulate protein synthesis by influencing the rate at which particular genes are transcribed (see transcription).

Testosterone has several major actions. It provides negative feedback inhibition on the secretion of gonadotropin-releasing hormone from the hypothalamus and the secretion of luteinizing hormone from the pituitary gland. It also directs the development of the embryonic Wolffian ducts into the vas deferens (ductus deferens) and seminal vesicles and stimulates the formation of muscle and bone. Dihydrotestosterone is responsible for sperm maturation during spermatogenesis, for the formation of the prostate gland and external genitalia, and for sexual maturation at puberty.

Testosterone can be manufactured by chemical and microbiological modification of inexpensive steroids, such as diosgenin. It is used clinically to treat testicular insufficiency, to suppress lactation (milk production), and to treat certain types of breast cancer.

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Testosterone

Testosterone is a steroid hormone that acts in vertebrates to regulate many sexually dimorphic traits and express many fitness related traits in males (Zysline et al. 2006). A hormone is a secreted chemical messenger that coordinates cell-to-cell communication. Testosterone belongs to the class of steroid hormones known as androgensthe generic term for any natural or synthetic compound that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to androgen receptors, including the activity of the accessory male sex organs and development of male secondary sex characteristics.

Steroid hormones such as testosterone (and estradiol on the female side) act early in development to organize male or female phenotypes that are activated later (Zysline et al. 2006). Testosterone's chemical formula is C19H28O2.

Although testosterone in vertebrates can activate male-typical phenotypes, testosterone's presence and action is not limited to males, and both sexes of most vertebrate taxa naturally produce testosterone (Zysline et al. 2006; Nelson 2000). In mammals, including humans, testosterone is primarily synthesized in the male's testes, but small amounts are also secreted by the female ovaries, the placenta, and the adrenal glands of both sexes.

Scientists have isolated testosterone and developed procedures for utilizing it medically to treat a wide variety of medical and psychological conditions, including low libido and even depression. This represents one aspect of human creativityutilizing it in service to others. However, human creativity can also be applied toward ill purposes, and testosterone provides a good example. Despite known side effects, some have used testosterone and other steroids to gain unfair competitive advantage in sports. Some athletes have admitted winning competitions, such as track and field events while circumventing the rules with performance enhancing drugs, to the detriment of honest competitors. This case of sacrificing others and the sport for one's personal gain reveals an unethical application of human creativity.

Testosterone's effects can be classified as either anabolic (related to protein synthesis and growth) or virilizing (related to the biological development of male sex characteristics). However, the two categories are closely related:

Greatly differing amounts of testosterone prenatally, at puberty, and throughout life account for a share of biological differences between males and females. On average, the adult male human produces about 20 to 30 times the amount of testosterone synthesized by an adult female (Larsen, et al. 2002). Nonetheless, like men, women rely on testosterone (albeit in significantly smaller quantities) to maintain libido, bone density, and muscle mass throughout their lives.

Since testosterone was isolated by scientists in the 1930s, it has been used to treat a host of clinical issues, ranging from hypogonadism (the underproduction of natural testosterone) to certain forms of cancer, osteoporosis, and depression. More recently, testosterone replacement therapy has become available to older men, whose testosterone levels naturally decline with age; however, large-scale trials to assess the efficiency and long-term safety of this treatment are still lacking.

Anabolic steroids, a category which includes testosterone and its derivatives, have also received attention due to their controversial use to increase muscle mass and enhance athletic performance. Anabolic steroids were designated a controlled substance by the United States Congress in 1990, under the Anabolic Steroid Control Act; Canada, the United Kingdom, Australia, Argentina, and Brazil also have laws controlling their use and distribution (The Steroid Group, 2006).

Like other steroid hormones, testosterone is derived from cholesterol, a sterol lipid with the chemical formula C27H45OH. Steroids are characterized by a carbon skeleton with four fused rings; they are distinguished by the functional groups attached to the rings.

Androgens (such as testosterone) are a major class of steroid hormones responsible for the development of male secondary sex characteristics. Testosterone is derived from the androgen androstenedione via a reduction of its 17-keto group.

The presence of a hydroxyl group (-OH) at position C-17 has enabled the development of synthetic forms of testosterone that can be administered in therapeutic treatments:

Most hormones are synthesized in a specialized tissue, then released to target cells as needed. The largest amount of testosterone is produced by the testes in men, but it is also synthesized in smaller quantities in women by the thecal cells of the ovaries, the placenta, and the zona reticularis of the adrenal cortex in both sexes.

In the testes, testosterone is specifically produced by the Leydig cells. The male generative glands also contain the Sertoli cells, which require testosterone for spermatogenesis (the synthesis of spermatozoa).

Because testosterone is not soluble in water, it is transported to target cells bound to a specific plasma protein called sex hormone binding globulin (SHBG). When a hormone arrives at the target cell, it binds to, or fits, a site on the receptor protein. Binding creates a ligand-receptor complex, causing a conformational change (a change in the molecule's structural arrangement) that initiates a sequence of reactions leading to a change in cellular function.

The effects of testosterone in humans and other vertebrates are triggered via two main mechanisms: (1) by activation of the androgen receptor and (2) by conversion of testosterone to the steroid estradiol, the major estrogen in humans, which in turn activates certain estrogen receptors.

The rate of hormone biosynthesis and secretion is often regulated by feedback circuits, in which changes in the level of one hormone affects the levels of other hormones. Luteinizing hormone (LH), which is synthesized and secreted by the anterior lobe of the pituitary gland, functions in the regulation of testosterone levels. LH acts upon the Leydig cells of the testis to stimulate testosterone production. LH's release is controlled by pulses of gonadotropin-releasing hormone (GnRH) from the hypothalamus. These pulses, in turn, are subject to estrogen feedback from the gonads.

Testosterone has its greatest impact on sexual differentiation during two stages of life: (1) Before birth and (2) during puberty.

Most prenatal androgen effects in humans occur between the 7th and 12th weeks of gestation, and are responsible for the masculinization of the developing fetus. Changes include closure of the perineum, thinning and rugation of the scrotum, growth of the penis, and closure of the urethral groove to the tip of the penis.

Prenatal virilization of genetic females and undervirilization of genetic males are common causes of ambiguous genitalia and intersex conditions. Undervirilization can occur if a genetic male cannot produce enough androgen or the body tissues are unable to respond to it. In females, intrauterine exposure to heightened levels of testosterone leads to profound genital abnormalities. In humans, for example, excessive exposure to androgens in the womb gives a girl a greatly enlarged clitoris and a vagina that is partially fused shut. In the most severe form of congenital adrenal hyperplasia, complete masculinization of a genetically female fetus results in an apparently normal baby boy with no palpable testes. More often, the virilization is partial and the genitalia are ambiguous.

Postnatal effects in both males and females are mostly dependent on the levels and duration of circulating free testosterone.

Early postnatal effects are the first visible effects of rising androgen levels in childhood, and occur in both boys and girls during puberty. They include adult-type body odor, increased oiliness of skin (acne), appearance of pubic hair and underarm hair, growth spurts (accelerated bone maturation), and the appearance of fine upper lip and sideburn hair.

In males, the following advanced postnatal effects typically manifest themselves during late puberty:

Adult testosterone effects are more clearly demonstrable in males than in females, but are likely important to both sexes. Some of these effects may decline as testosterone levels decrease in the later decades of adult life. They include maintenance of muscle mass, maintenance of bone density, libido, and clitoral engorgement/penile erection frequency.

Behavioral effects of hormones are difficult to understand and to attribute to a given cause; in addition, a given hormone can have very different effects on behavior depending on the region of the central nervous system on which it acts. Nonetheless, high levels of circulating testosterone have been correlated to aggression in a variety of vertebrate species. For elephant bulls in musth (period condition in bull elephants), the amount of testosterone in the blood soars to levels fifty times higher than usual; during this period, male elephants demonstrate a mix of desperate lust and rage and are likely to engage in fights with other similarly affected males. Moreover, abnormal intrauterine exposure to androgens fosters aggression in females: Female mice that are snuggled between their brothers during fetal life are exposed to higher levels of androgens than females nestled between sisters and are more aggressive adults (Judson 2002).

The aggression associated with high levels of naturally circulating testosterone seems to be closely related to reproduction. For example, in male red-winged blackbirds (agelaius phoeniceus), testosterone levels peak during the two-week period when males are defending breeding territories and guarding their mates from rivals (Barnard 2003).

A experimental study on female dark-eyed juncos, a species of bird, found that exogenously increased testosterone levels led to increased intrasexual aggression (as well as decreased cell-mediated immune function) (Zysling et al. 2006). Increased aggressive behavior in female birds might help them acquire high quality mates or nesting sites, be more active in nest defense, or help win territorial interactions with other females, but might also lead to increased energy expenditure, potential for injury, or risk of predation (Zysling et al. 2006).

Various forms of exogenous (externally produced) testosterone and other anabolic steroids are used in medical treatment and (more controversially) as a bodybuilding tool or performance enhancer; they are most commonly administered in oral, injectable, and transdermal form.

Testosterone was originally used for the treatment of males who have little or no natural testosterone productionthat is, males with hypogonadism. Hormone replacement therapy maintains blood testosterone levels in the normal range.

Over the years, testosterone has been administered to treat a variety of conditions, including infertility, lack of libido or erectile dysfunction, osteoporosis, and for penile enlargement, height growth, bone marrow stimulation and reversal of anemia, and even appetite stimulation.

To take advantage of its virilizing effects, testosterone is often administered to female-to-male transsexual men as part of hormone replacement therapy, with a "target level" of the normal male testosterone level.

Decline of testosterone production with age has led to a demand for androgen replacement therapy, though there is disagreement within the medical community about the efficacy and safety of such treatments. Caution about embracing testosterone replacement therapy stems in part from the lessons of female hormone replacement therapy trials, where initially promising results were later refuted by larger studies. Still, testosterone replacement therapies in women to treat or prevent osteoporosis have yet to show the risks now associated with estrogen replacement therapies.

Women may use testosterone to treat low libido, often a symptom or outcome of hormonal contraceptive use. Women may also use testosterone therapies to treat or prevent loss of bone density and muscle mass and to treat certain kinds of depression.

Some drugs work to reduce testosterone's effects. For example, finasteride inhibits the conversion of testosterone into its metabolite dihydrotestosterone (DHT). By lowering levels of DHT, finasteride may be used to treat benign prostatic hyperplasia (BPH) and androgenetic alopecia (male-pattern baldness).

Testosterone administered to an athlete in order to improve performance is considered to be a form of doping in most sports. After a series of scandals and publicity in the 1980s (such as runner Ben Johnson's improved performance at the 1988 Summer Olympics), prohibitions of anabolic steroid use were renewed or strengthened by many sports organizations. Testosterone and other anabolic steroids were designated a controlled substance by the United States Congress in 1990.

Anabolic steroids have been associated with numerous side effects when administered in excessive doses; these include elevated cholesterol levels, acne, elevated blood pressure, hepatotoxicity, and alterations in left ventricle morphology. Adolescents who abuse anabolic steroids also risk stunted growth.

Some side effects are gender specific. Development of breast tissue in males, a condition called gynecomastia, is usually caused by high levels of circulating estrogen, the result of the increased conversion of testosterone to estrogen via an aromatase enzyme. Another male-specific side effect is testicular atrophy, a temporary reduction in the size of the testes. Possible female-specific side effects include increases in hair, deepening of the voice, enlarged clitoris (clitoral hypertrophy), as well as temporary decreases in menstrual cycles. When taken during pregnancy, anabolic steroids can affect fetal development.

A popular conception, perhaps misconception, regarding the side effects of anabolic steroids is that use leads to increased aggression, known in popular parlance as roid rage. Some early studies have shown a slight correlation between manic symptoms and anabolic steroid use; however, more comprehensive and recent studies have brought into question their methodology and conclusions (Pope and Katz 1988). Many scientists and medical professionals have concluded that anabolic steroids do not markedly increase aggressive behaviors (Fudala et al. 2003; Pope et al. 2000; OConner 2002).

All links retrieved November 20, 2015.

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It's no secret financial tradershave always beenpredominately male.

So, when a group of researchers with the Ivey Business School at Western University in London, Ont., set out toat look at the role of testosterone on the markets, it wasn't a far-flung idea.

"We wanted to simulate what happens when people are at elevated levels ... how would they trade with high testosterone," saidIveyassistant finance professorand researcher AmosNadlerin an interview with CBC Radio's London Morning.

For their "experimental market" study, researchers divided 140 men into two groups and let them do mock trading amongstthemselves. One group received a placebo treatment the other, a topical gel containing testosterone.

Amos Nadler is an assistant finance professor with the Ivey Business School at Western University. He was involved in the study on financial trading and testosterone. (Courtesy: Ivey School of Business, Western University)

The result? The testosterone-fuelled group was more reckless in its trading, willing to bid well above the value of a given commodity in hopes of a higher return. Researchers say the behaviour increased the odds of a market crash.

By comparison, the placebo group was trading more rationally, buying low to sell high, instead of buying high to sell higher.

"Your body produces more testosterone when you prepared for a challenge ... even more testosterone when you are winning," said Nadler.

When the financial crash hit Wall Street a decade ago, a funny thing happened. Male financial executives started turning to doctors for testosterone supplements in hopes it would boost their output and sharpen their faculties.

"All of these men are under tonnes of stress, and stress will reduce their levels of testosterone," said Manhattan-based Dr. LionelBissoonin a story in the Financial Times in 2012

Nadler said studies based on gender rather than the male hormone found that women also tend to keep a more level head in the high-adrenalin setting of a trading floor.

"Single males over-traded and lost the most money, while women tend to be more conservative and actually make more money than men," said Nadler

The Ivey study was done in collaboration with the University of Oxford and Claremont Graduate University in Claremont, Calif.

While it found that testosterone clearly played a role in more reckless trading and spending, Nadler cautions male traders aren't all bad.

"Being slightly more impulsive can be a good thing ... there are some results that showed the higher-testosterone guys made a bit more money than their counterparts," said Nadler.

"It can also be very harmful in some situations if you are being impulsive."

The research paper, titledThe Bull of Wall Street: Experimental Analysis of Testosterone and Asset Trading, will appear in an upcoming issue ofthe publication, Management Science.

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Reuters Health - Doctors are doing fewer weight-loss procedures to implant adjustable bands around the stomach and more operations to remove the devices or alter them, a U.S. study suggests.

Researchers focused on a type of weight-loss surgery known as laparoscopic adjustable gastric banding, a minimally invasive procedure that involves placing an inflatable belt around the upper portion of the stomach that reduces the amount of food it can hold. People are advised to eat portions about the size of a shot glass post-surgery.

Nationwide, a total of 28,202 patients underwent procedures to implant laparoscopic adjustable gastric bands (LAGB) from 2007 to 2015, the study found. Over that same period, 12,157 people had gastric bands removed, or explanted.

Starting in 2013, though, surgeons did more procedures to take bands out than to put them in, the study team reports in the Journal of the American College of Surgeons.

A newer alternative in weight-loss surgery known as a laparoscopic sleeve gastrectomy that appears to be safer and more effective may be driving this trend, said senior study author Dr. Ninh Nguyen, chief of the division of gastrointestinal and bariatric surgery at the University of California, Irvine School of Medicine.

Compared to the adjustable gastric banding, the laparoscopic sleeve gastrectomy is associated with improved weight loss and lower incidence of late complications, Nguyen said by email. The late complication rate requiring revision (procedures) after sleeve gastrectomy is one-fourth that of gastric banding.

More than half of weight-loss procedures done today use the sleeve gastrectomy, which reduces the stomach to the size of a banana, according to the American Society for Metabolic and Bariatric Surgery.

Procedures to remove or adjust gastric bands were associated with longer hospital stays, a greater number ofserious complications and more admissions to intensive care units compared withoperations to implant the devices, the study found.

Researchers didnt find any difference in death rates or costs between implantation procedures and operations to remove or fix the bands, with both types of surgery costing an average of $11,600 to $12,000.

One limitation of the study is that researchers only examined procedures done at academic medical centers, although the authors suggest that trends might be similar at community hospitals.

Another drawback is the lack of data explaining why bands were removed. That makes it impossible to say if the removal happened after complications or because patients elected to switch to a different, newer alternative such as the sleeve gastrectomy to see if they could achieve more weight loss.

Most often, when the gastric bands are removed its either because patients couldnt tolerate the devices being tightened or because they didnt lose enough weight, said Dr. Anita Courcoulas, chief of minimally invasive bariatric and general surgery at the University of Pittsburgh Medical Center.

Because the sleeve is still relatively new, however, its too soon to say whether it will achieve better weight loss or fewer complications over the long term, Courcoulas, who wasnt involved in the study, said by email.

Enthusiasm for the sleeve as a replacement for the band should be tempered with the knowledge that longer-term outcomes are still sorely lacking, Courcoulas added. It will take time, patience, and a dynamic evaluation of the evidence as it evolves to draw more final conclusions about the longer-term comparative effectiveness of bariatric procedures.

SOURCE: bit.ly/2vL18Pf Journal of the American College of Surgeons, online July 25, 2017.

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Surgeries to remove weight-loss devices on the rise - Reuters - Reuters

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By Pam Stuppy

According to statistics, as high as 2 percent to 40 percent of American women experience stress urinary incontinence. SUI occurs when urinary leakage is triggered by activities that increase intra-abdominal pressure. Examples include sneezing, coughing, laughing or certain forms of physical activity.

For younger women, increased involvement in high impact physical activity or pregnancy may be the precipitating causes. Approximately 19 percent to 75 percent of pregnant women experience SUI. Interestingly, middle age women going through perimenopause (around 45-49 years of age) are the age bracket at highest risk, even more so than older women.

SUI involves functions of the bladder sphincter and/or the pelvic floor muscles. Pressure in these areas can lead to accidental opening of the urethra resulting in leakage. For this reason, activities that increase intra-abdominal pressure or even the presence of excess abdominal fat can increase the risk.

A number of factors can contribute to the risk of SUI. Studies indicate that there may be a genetic connection. Also, gynecological issues related to hormones or physiological changes can be triggers. This includes decreases in estrogen levels and/or weakening of pelvic floor muscles. Having had multiple births can be a contributing factor as well.

Constipation can cause pelvic floor stress due to straining. Many medications as well as diet, dehydration and sedentary behaviors can affect constipation. Women who experience SUI are often fearful of leakage and restrict fluid intake as a result. This can further increase the risk of constipation and its negative impact on SUI. They may also limit physical activity for the same reason, which can then lead to increased abdominal fat.

Chronic coughing that causes pelvic floor stress, such as from smoking or asthma, can increase the risk of SUI. High impact exercise over an extended period of time or excessive weight lifting are other risk factors.

Rapid weight increase or long-term elevated body weight, especially in the abdominal area, can lead to SUI. Excess fat not only puts pressure on the bladder, but can also weaken the pelvic floor muscles and tissues supporting the urethra.

In addition, visceral abdominal fat can negatively affect hormones that otherwise sustain a healthy pelvic floor. Some of these hormones are also involved in fullness and hunger cues so changes can lead to weight gain. Note that abdominal fat may increase the risk of bladder inflammation, which often results in increased urinary frequency and urgency.

Factors that increase abdominal fat would then be considered contributors to SUI. Diet is implicated since excess calorie intake with a higher intake of added sugars/sugar sweetened beverages can promote abdominal fat. Studies suggest that higher saturated fat intake is another risk factor for SUI. A sedentary lifestyle is another contributor. According to the research, higher levels of total daily fluid intake does not increase the risk of SUI or the onset of symptoms.

Sleep habits have been shown to be related to SUI risk. A lack of restorative sleep exacerbates SUI symptoms. A high intake of calories or consuming alcohol or caffeine shortly before bedtime can counter high quality sleep as well. There is also an association between higher levels of abdominal fat and having to get up to urinate more frequently through the night. This in turn interferes with proper sleep. Being overweight increases the possibility of sleep apnea, which reduces sleep quality if untreated.

So, in considering the possible factors that can increase the risk of SUI, making a few lifestyle changes can help to reduce that risk. Losing some weight, even if not down to an ideal body weight, can be especially helpful. As part of weight loss, a healthy diet that limits added sugars and saturated fat is useful. The DASH diet, which was originally developed to lower blood pressure, has been suggested as a good format for healthy weight loss, promotes higher fiber intake, and recommends a lower intake of saturated fats.

Exercise can not only benefit weight loss, but can directly strengthen the tissues involved in SUI. Ongoing moderate activity is a better choice than higher impact exercises or extreme weight lifting. A good goal is at least 30 minutes of cardiovascular exercise most days. In addition, exercises that strengthen the pelvic floor muscles and other supporting tissues are recommended. A physical therapist can be extremely helpful for guidance in this area.

Addressing constipation reduces the stress on the pelvic floor from straining. A high fiber diet with sufficient fluids is a great goal. If a medication is causing the constipation, consider if there is another medication that could be substituted that does not promote constipation.

Improving sleep hygiene may involve a number of action steps. As noted, weight loss can help to reduce urinary frequency during the night. Reducing the intake of food and fluids shortly before bedtime can improve sleep quality, as can limiting alcohol intake and caffeine within about six hours or so before bedtime. Obviously, addressing sleep apnea can improve sleep as well.

If stress urinary incontinence is negatively affecting the quality of your life, consider what steps you can take to reduce the risk of symptoms. Do not hesitate to ask professionals for support and guidance medical professionals, a physical therapist, exercise professionals, a registered dietitian, or possibly a mental health professional can help you deal with the stress of stress urinary incontinence.

Pam Stuppy, MS, RD, CSSD, LD, is a registered, licensed dietitian with nutrition counseling offices in York, Maine, and Portsmouth. She is also the nutritionist for Phillips Exeter Academy, presents workshops nationally, and is board certified as a specialist in sports dietetics. Visit http://www.pamstuppynutrition.com for nutrition information, healthy cooking tips and recipe ideas.

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Could shivering in the cold be a way to shed weight and possibly prevent diabetes?

Exposure to cold is the most well-known and well-studied mechanism for switching on energy-burning brown fat, which seems to protect mice from developing obesity. It remains to be seen whether the same process can help people.

Humans have three kinds of fat. White adipose tissue, or white fat, comprises the majority of fat in bodies; its purpose is to store energy for future use. Brown fat is different; its function is to generate heat to maintain body temperature.

Until recently, it was thought that adults did not have brown fat, that it only existed in babies to help them stay warm before they could move around and then it essentially vanished. But beginning in 2009, studies have found that many adults have brown fat and that people with more of it tend to be leaner and have lower blood sugar levels.

The third kind of fat, beige fat, appears to convert from white to brown when stressed by exposure to cold, and then back to white. This process is encouraging for scientists trying to figure out how to increase brown fat to improve healthy functioning of the body.

Paul Lee, an endocrinologist at the Garvan Institute of Medical Research in Sydney, where he leads the Brown Fat Physiology Group. said a balanced diet and regular exercise were the cornerstones of healthy metabolism, but sustaining either was difficult for most people.

Understanding how brown fat could benefit our health opens up a new direction in obesity research, he said.

It is not a solution to obesity, but it is an opportunity to explore an alternative strategy for curbing the obesity epidemic.

Dr Lee said that when the body sensed the cold, the brain released norepinephrine, a chemical that essentially ignites the fat-burning process within brown fat.

When there was not enough brown fat, the body had to turn to less-efficient heat-generating models, such as shivering.

Aaron Cypess, a clinical investigator at the National Institute of Diabetes and Digestive and Kidney Diseases, calls brown fat the principal organ responsible for generating heat in laboratory animals.

In mice and rats, chronic activation of brown fat [by exposing them to low temperatures or to drugs that target brown fat] ... is associated with a reduction in liver fat, a resistance to diet-induced obesity and improvement in insulin release, Dr Cypess said.

All of these benefits and others may also apply to people, but it will take much longer to prove because studies in humans have to be conducted differently.

While white fat is easy to spot in humans think abdomen, hips, buttocks and thighs brown fat tends to be located around the neck and above the collarbone, along the spine and near the kidneys.

Dr Cypess said humans were genetically more diverse than lab mice, which produces results with much higher variability.

Dr Lee said that when people are cold and begin to shiver, their muscles release irisin, a hormone that turns white fat into brown fat. The more a person shivers, the more irisin is released into the bloodstream.

A 2014 study by Dr Lee dubbed the ICEMAN study found that after a month of sleeping at cool temperatures, five men increased their stores of brown fat by 30 to 40 per cent and metabolised sugars more efficiently after a meal, which could be helpful for people with diabetes.

When the sleeping temperature was raised, the brown stores dropped.

(Another recent study found that brown fat also may be stimulated by taking a drug used to treat overactive bladder.)

Dr Cypess said this research made it clear that activating or increasing brown fat stores might prevent weight gain, lead to weight loss and provide a new avenue for treating diabetes and obesity.

Can the average person embark on a shiver diet to lose weight?

Dr Lee said he believed the current evidence did not support the notion that shivering might be a route to losing weight. (Despite the studys name, ICEMAN the Impact of Chronic Cold Exposure in Humans exposed participants to only mild cold, not shiveringly low temperatures.)

Dr Cypess said shivering to lose weight was an interesting idea, but there were many unknowns.

First, is it safe?

Dr Lee said shivering causes stress and could harm the body, which explains why the human body has evolved mechanisms to turn on brown fat or to turn white fat into brown fat.

In most people, Dr Cypess said, shivering caused increases in blood pressure that over the years could damage blood vessels in the brain, heart and kidneys.

Additionally, there was no evidence to prove that a low-temperature regimen could be effective long-term.

One of the biggest limitations of weight-loss interventions is that the body learns to compensate to maintain itself, and that might be true with a shiver diet.

Dr Lee and Dr Cypess agree that no weight-loss regimen should be recommended without a great deal of evidence that it will work for more than a few weeks or months and that the weight loss can be sustained evidence that doesnt exist.

Finally, Dr Cypess said, being cold is extremely uncomfortable.

While suggestions exist that long-term activation of brown fat could be beneficial to weight loss and diabetes reduction, this has yet to be proven, he said.

Francesco Celi, chair of the division of endocrinology, diabetes and metabolism at the Virginia Commonwealth University School of Medicine, said he expected future research will include conducting studies in humans that will test various interventions (drugs or environmental modifications) to expand and activate brown fat to help scientists determine what kind of metabolic improvements can occur.

And by studying the various responses to interventions, researchers will be able to determine which patients respond better to brown-tissue expansion and perhaps why they do.

Dr Cypess said he expected scientists to focus on determining to what extent adult brown fat contributed to getting rid of excess calories, how brown fat could be used to bring down blood sugar levels and how brown fat interacted with other organs to keep people healthy.

But even with all that, he said: Basically, the issue of losing weight is about controlling the amount of food we put into our mouths.

The Washington Post

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WASHINGTON There's a group of people who suffer from what I'd call "serial get-out-of-debt disorder."

I know it's a mouthful, but it's a real condition for folks who find themselves stuck in a cycle of getting in and out of debt.

This ailment typically affects people who live above their means. One long-term effect of this ailment is the inability to save enough for emergencies, retirement or sending children to college without incurring more debt.

Here is how you can tell if you have this disorder:

You stay in debt, mostly with credit cards. But it could also include personal loans or frequent borrowing from your retirement plan.

You are rarely without a car loan. You repeatedly trade in your car for an upgrade because you feel entitled. Or because you're tired of fixing your car even though the repairs are still far less expensive than purchasing another vehicle new or used.

You feel remorse about amassing more debt than you can handle.

Your regret creates anxiety, weight loss or weight gain. You can't sleep at night.

If you're married, you fight about the debt with your spouse, putting a strain on your marriage which can manifest in more spending.

You can't take the stack of bills anymore, and you declare that you're ready to be healed.

You hunker down, aggressively cut expenses and maybe even get another job or work more hours to get out of debt.

You finally pay off the consumer debt. You're in remission. But because you haven't dealt with why you got into debt, you're right back in trouble.

During a recent online chat, I received a plea for advice from a reader suffering from this condition.

"I am in debt. Again," the person wrote. "I promised myself it wouldn't happen again after I filed for bankruptcy in 2000, but 17 years later I'm back in debt."

The reader says this time the debt is moderate. She's got $10,000 in credit card debt, which includes charges for car repairs and utility bills.

"My mortgage is behind by one month," she wrote. "I have steady income, but it's just my income, as my husband is an entrepreneur and companies have started paying when they want, which is not on time."

To alleviate their symptoms, sufferers often turn to a common cure.

"I am considering asking a family member to co-sign or obtain a loan for me to cover the debt so I can have one bill," the reader wrote. "The $10,000 loan would put me at zero debt other than that loan and student loans. Freeing up money would maybe help get me back on track."

So her question to me: "Does this make sense? I know I won't default/mess up the family member. I can't get a loan on my own."

Here's the regimen of treatment I recommend for this disorder:

Diagnose why you keep getting into debt In this case, it could be the unpredictable payments to her husband's business. The Small Business Administration has resources to help. On its website, http://www.sba.gov, search for this blog post: "4 Ways to Better Manage Irregular Income."

But if the earnings from her husband's entrepreneurial enterprise are continually inadequate to meet this couple's household needs, then perhaps he could take on another job. Or maybe self-employment isn't working, which is why they are using credit to make ends meet.

Get help The reader said, "I've learned my lesson, really."

If income isn't the issue, you may need therapy if your spending is a symptom of psychological issues. Maybe you need to deal with childhood trauma. Perhaps you spend more when you're under a lot of stress. And when the stress is gone, you clear up your debt. But when it returns, you go back to shopping as a relief.

If it's just an aversion to budgeting, get help from a nonprofit credit-counseling agency. To find a local agency, go to the National Foundation for Credit Counseling's website: nfcc.org. The agency can also help you negotiate with creditors and set up a debt payment plan.

Don't put a Band-Aid on the problem by dragging in friends or relatives No, you should not ask a family member to co-sign a loan. You will be putting his or her financial health on the line. Besides, in my experience, when people get a consolidation loan, they get a false sense of financial freedom. The zero balances on their credit cards are too tempting.

Unless you address the root cause of your serial get-out-of-debt disorder and take steps to prevent its recurrence, this condition won't be cured.

Readers can write to Michelle Singletary c/o The Washington Post, 1150 15th St., N.W., Washington, D.C. 20071. Her email address is michelle.singletary@washpost.com.

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Do you have serial get-out-of-debt disorder? - South Bend Tribune

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Losing weight is tough. It would be easier if a benevolent someone concerned about your health controlled exactly how much you ate and how often you exercised, right? Thats the situation for most dogs and cats in the United States, and yet the majority are overweight or obese.

As with our own dieting woes, the unpleasant prospect of the simple solution feeding our furry friends less makes us reach for alternative, quick-fix strategies. Many pet parents have turned to radically new menus. These grain-free, all-meat and raw-food diets are inspired by the meals eaten by wild relatives of our fidos and felixes.

But are these diets really better for our pets? Veterinarians and pet nutrition researchers say probably not.

According to clinical veterinary nutritionists at Tufts University, grain-free foods were one of the fastest-growing sectors of the pet food market in 2016. All I ever hear is, oh, on a good diet, its grain free, said Dena Lock, a veterinarian in Texas. The majority of her pet patients are overweight.

Why have these pet diets become so popular?

Its a marketing trend, Lock said.

Grain-free is marketing. Its only marketing, said Cailin Heinze, a small-animal nutritionist at Tufts Universitys Cummings School of Veterinary Medicine. A lot of foods market themselves by what theyre not including, and the implication is that the excluded ingredient must be bad.

Grain-free is definitely a marketing technique that has been very successful, said Jennifer Larsen, a clinical nutritionist at the University of California Veterinary School in Davis. (Disclosure: I went to graduate school at the University of California at Davis, but studied plants, not pets.) People think that if they pay a lot for food and there are a lot of exclusions on the bag, that the food is healthier, but theyre buying an idea, she said, not necessarily a superior product.

There is absolutely no data to support the idea that grain-free diets are better for pets, Heinze and Larsen noted.

Some pet owners have a false impression that grains are more likely to cause an allergic reaction, but its much more common for dogs to have allergies to meat than to grain, Heinz said. Chicken, beef, eggs, dairy and wheat are the most common allergies in dogs. And its not that theres anything particularly allergenic about these foods, she said, theyre just the most frequently used ingredients.

Marketing campaigns such as Blue Buffalos Wilderness or Chewys Taste of Wild claim that their grain-free, meat-forward formulations better reflect the ancestral diets of our dogs and cats evolutionary predecessors, but the veterinarians I spoke with also questioned this logic.

For one, our pets wild cousins arent all that healthy. People believe that nature is best, Larsen said, but animals in the wild dont live that long and they dont lead very healthy lives.

For dogs, we know that they have diverged from wolves genetically in their ability to digest starches. Dogs arent wolves, said Robert Wayne, a canine geneticist at UCLA. They have adapted to a human diet. Research in Waynes lab showed that most wolves carry two copies of a gene involved in starch digestion, while dogs have between three and 29 copies. According to Heinze, the average dog can easily handle 50 percent of its diet as carbs.

For cats, this argument makes a little more sense. Cats are carnivores rather than omnivores, so they have higher protein requirements than dogs, but cats can digest and utilize carbohydrates quite well, said Andrea Fascetti, a veterinary nutritionist at the University of California Veterinary School in Davis.

Many grain-free pet foods are made with starch from potatoes or lentils and they may be higher in fat. If you cut grains but increase calories, your pet is going to gain weight, Heinze said.

Dogs and cats also have a drastically different lifestyle from wolves or tigers. Pets are almost always spayed and neutered which is in itself a risk factor for obesity. And most live inside or in pens, so their energy needs are reduced dramatically.

In the wild, wolves and feline predators eat the hair, bones and cartilage of their prey, not just meat. For pet owners who do choose to feed their animals an all-meat diet, its essential to add supplements to make sure their pet isnt missing out on key nutrients such as calcium, Fascetti said. And theres the environmental impact to consider: Pets consume a quarter of all animal-derived calories in the United States.

Experts especially caution against feeding pets raw meat. Its not uncommon to find things like salmonella and E. coli and listeria in raw meat, Larsen said. There are a lot of microbes present in our farming systems, and unlike when an animal is hunting in the wild, there are many opportunities for bacteria to contaminate meat between the time an animal is slaughtered and when it reaches our kitchens.

Even if eating contaminated meat doesnt make pets sick, it poses a health risk to pet owners and their children who handle the pet food and waste. The Centers for Disease Control and Prevention and the Food and Drug Administration both warn against feeding raw meat to your pets, and I really cant advocate it, because its not safe for the whole family, Heinze said.

But what about all those benefits you hear about from feeding a raw diet, like shiny coats and less frequent stools? I cant tell you how many clients send me pictures of poop, Larsen said. But changes to a pets bathroom habits dont have anything to do with their food being raw.

Raw diets tend to be lower in fiber, and high fiber probably results in larger stools. But we dont have a sense of whether stool quality and quantity correlate with health, Fascetti said. And that shiny coat probably is because of high fat, Heinze said.

If pet owners wish to formulate their own diets, they should work with their veterinarian and a board-certified nutritionist. If youre feeding your pet a balanced diet such as in a commercial chow, obesity is the biggest nutrition issue pet owners should worry about, Heinze said.

We want our pets to enjoy what theyre eating, so many foods and especially treats are formulated to be high in fat, Larsen said. Most people dont realize that a milk bone has about as many calories as a candy bar, Lock said.

I know the struggle. My own hefty husky mix stares at me with her big brown eyes and licks the window whenever she wants food. Ive taken to calling the dental chews I buy her guilt-a-bones, because I cant help but give her one every time I leave.

But studies have found that feeding dogs to maintain a lean body weight has very positive effects on their overall health and can even increase life span. This is also the case in mice and rats, and we believe that these findings apply to cats as well, Fascetti said.

Theres no one magic diet for every animal. These experts strongly recommend working with your veterinarian to find a diet that works for you and your pet. When it comes to navigating marketing claims in the pet food aisle, Lock suggests finding a company that employs a veterinary nutritionist and does feeding trials. Try not to get too hung up on the no list, Heinze said. Claims like no gluten, no grains, and no soy generally mean no science.

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Grain-Free Pet Foods Are No Healthier, Vets Say - Valley News

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This is the diet that has absolutely nothing to do with eating but thats proven to be way more effective in getting you healthy than any other regimen.

According to a study published in The Lancet, sleep is crucial for metabolic function and hormone stability. Hormones and metabolism play a pivotal role in health, affecting everything from diabetes prevention to heart disease risk.

When participants sleep was restricted, they experienced an increase in stress hormones and a decrease in the speed of their metabolism.

Another study found that a lack of sleep contributed to a sharp decrease in leptin the hormone responsible for regulating fat storage. They also witnessed an increase in ghrelin a hormone that increases appetite.

If youre not sleeping enough, youre obviously going to be tired. Your body is going to get stressed and start sending signals to your body to put on weight. The weight, from your bodys perspective, is there as a reservoir of energy. When you feel tired, its suspicious that it might need it.

You dont have to cut the carbs off your hamburger, start drinking wellness shots that taste more like grass than juice, or choke down harsh sips of apple cider vinegar to foster a better relationship with your body.

All you have to do is simple: Sleep.

Not before you eat, not excessively, not five times a day, or whatever other wild ideas are ricocheting through your mind.

Just sleep enough. And sleep well.

Of course, this is easier said than done. Thats where the concept of the diet comes in. Diets are often seen as temporary a short-term set of rules to carry you through a healthy change or two that hopefully sticks after its over, when the clock strikes midnight and boom you can eat pasta again.

With food, diets dont work. Theyre often extreme, restrictive, and leave you drooling desirously over a cupcake you never even blinked at before. That doesnt happen on a sleep diet. You dont crave consciousness when you start to get enough sleep. If youre somehow taking it to the extreme (i.e., getting too much sleep) youll just wake up. Its the equivalent of accidentally eating a doughnut if youve gone too far and prohibited dessert.

The sleep diet, if done effectively, works. Its just not easy. Heres how to do it:

1. Set a time frame for the diet. One week is a good place to start.

2. Set your own rules. How much sleep do you want to get each night? Figure out the bedtime you would need to follow to accomplish the desired number of hours. Write it down.

3. For the time frame of your diet, stick to your bedtime. Thats the only rule to which this diet adheres. Its easy to remember, but surprisingly difficult to do.

But before you say, No, I cant do that, think about it for a second. Is it any harder than a typical diet? With those, you often have to eliminate entire sectors of your life. Happy hour with your coworkers? No drinking. Birthday cake with the kids for their birthday? Not for you!

Why do we perceive sleep as more extreme than those other restrictions restrictions that arent even all that good for you?

Sleep, on the other hand, is great for you. With a few extra hours of rest under your belt, youre likely to gravitate naturally towards your healthiest weight and feel much better, too.

If youre having trouble actually falling asleep once youve turned the lights out, try one of these natural remedies to help you sleep well.

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A Sleep Diet Is the Number One Way to Your Healthiest Body Yet - The Daily Meal

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