Medical doctors, MDs, and doctors of osteopathy, known as DOs, have similar training requiring four years of study in the basic and clinical sciences, and the successful completion of licensing exams Continue reading →
About one in three American adults have hypertension (high blood pressure), and according to the Centers for Disease Control and Prevention (CDC),1,2 hypertension is “the second greatest public health threat” in the US.Continue reading →
If you’ve heard that life is movement, it’s true. If you’ve heard that just sitting around can kill you, it’s also true. Physical inactivity is the fourth leading cause of death worldwide! You may have heard the media reporting recently on several studies showing that Continue reading →
Leptin is a powerful and influential hormone produced by your fat cells. It plays a key role in regulating energy intake and energy expenditure. By acquiring a better understanding of how leptin and its receptor interact, researchers now believe they will be able to find new treatments for obesity and other metabolic disorders
One dogma that has contributed to the ever-worsening health of the Western world is the belief that “a calorie is a calorie.” This simply isn’t true. The idea that obesity is the end result of eating too much and exercising too little; i.e. consuming more calories than you’re expending, is also false.
Fructose is ‘isocaloric but not isometabolic.” This means you can have the same amount of calories from fructose or glucose, Continue reading →
Obesity is common among patients with mental illness, occurring in up to 60% of patients with bipolar disorder, 70% of patients with schizophrenia, and 55% of patients with depression. A review by Taylor and colleagues in the current issue of the Canadian Journal of Psychiatry analyzes why mental illness is associated with higher rates of obesity. Although the use of psychoactive medications is an obvious reason for weight gain in this patient population, there is also evidence that disturbance of the sleep-wake cycle may promote a resistance to leptin, which promotes satiety, and higher levels of circulating ghrelin, which stimulates appetite. In addition, depression is associated with higher levels of circulating cortisol, which promotes weight gain. Finally, both mood disorders and obesity are marked by dopaminergic deficits. Continue reading →
One would think that eating too much would result in an abundance of nutritional support for cells. But being overweight and undernourished at the same time is a reality that is just beginning to be understood. It is quite strange to say to people that the more they eat, the more malnourished they are destined to be.
Overweight people more often than not suffer from gross malnutrition because the nutritional values of the basic foods available to us have been steadily dropping for the last 50 years even as toxic exposures increase. Obese people tend to eat too many processed white foods with the fiber removed along with many of the vitamins and minerals. Not enough fiber is another common problem with the obese.
New Brain Pathway for Regulating Weight, Bone Mass Identified
PRINCETON – Yale researchers have claimed that hormone leptin, which is critical for normal food intake and metabolism, appears to regulate bone mass and suppress appetite.
The hormone appears to regulate bone mass and weight by acting mainly through serotonin pathways in the brain.
“Our study challenges the view that the hypothalamus is the critical brain site where leptin acts directly to alter neuronal circuit function to suppress appetite and bone metabolism,” said Yale researcher and study co-author TamasHorvath.
“We’ve now found a novel explanation for how leptin can act on the brain,” Horvath added.
Food intake is influenced by signals that travel from the body to the brain. Leptin is one of the molecules that signal the brain to modulate food intake.
It is produced in fat cells and informs the brain of the metabolic state. If animals are missing leptin, or the leptin receptor, they eat too much and become severely obese.
To determine whether leptin regulates bone mass through serotonin pathways, Horvath and his colleagues analyzed multiple lines of mice that were genetically altered to remove serotonin in the brain.
“We found that when the serotonin pathway is turned off by leptin, the mice ate less, lost weight and their bones became weak,” said Horvath.
“When the pathway is turned on, the mice ate more, gained weight and had more bone mass. This might be why obese people tend to have much lower incidences of osteoporosis,” the expert added.
LUEBECK – A number of studies have linked chronic sleep deprivation to a heightened risk of obesity, diabetes and heart disease. Now, a small study suggests that low levels of physical activity during the day may partly account for the connection.
In a study of 15 healthy men, researchers found that a couple nights of grabbing only four hours of sleep caused the men to curtail their physical activity compared with days where they had gotten the standard eight hours the night before.
In contrast, there was no evidence that sleep loss altered blood levels of appetite-regulating hormones or caused the men to eat more the next day — effects that have been seen in a number of previous studies.
The implication is that there may be a broader range of reasons for the link between sleep loss and weight and health, the researchers report in the American Journal of Clinical Nutrition.
Practically speaking, the findings offer adults another reason to get enough sleep.
For healthy adults, that means regularly getting seven to eight hours per night, lead researcher Dr.SebastianM.Schmid, of the University of Luebeck in Germany, told Reuters Health in an email.
A number of large epidemiological studies have found associations between poor sleep and higher risks of obesity and other health problems. Since then, a few small studies done in the sleep lab have attempted to find the possible reasons for the connection.
In some, researchers have found evidence that sleep loss alters the regulation of the hunger hormones leptin and ghrelin, and may boost daytime appetite. Leptin, which helps regulate body weight, is secreted by fat cells; low blood levels of the hormone promote hunger, while increases tell the brain that the body is full and encourage calorie burning. Ghrelin is secreted by the stomach to boost appetite.
But another possibility is that sleep-deprived people are just too tired to be physically active during the day.
While that seems logical, apparently no human studies had examined the question before.
For the new study, Schmid and his colleagues had 15 healthy, normal-weight men go through two consecutive nights with four hours of sleep and two nights with eight hours of sleep.
After the first night, the men spent the day doing their normal activities, while wearing a wrist device that recorded their movements. After the second night, they came to the sleep lab, where they again wore the wrist devices and also had their levels of leptin and ghrelin measured and their calorie intake monitored.
The researchers found that, unexpectedly, the men showed no differences in their hormone levels, hunger or food intake after the four-hour night compared with the eight-hour night.
They were, however, less active after sleep-deprived nights — devoting both fewer minutes to physical activity and a smaller proportion of that time to more-intense exercise.
Last Updated: 2010-01-01 13:00:52 -0400 (Reuters Health)
When the men got eight hours of sleep, they spent an average of 25 percent of their active time performing higher-intensity exercise; that declined to about 22 percent with four hours of sleep.
Over time, such differences could affect a person’s weight and general health, according to Schmid’s team.
The findings do not mean that sleep loss has no effects on hunger hormones and appetite, as earlier studies have suggested that it does. However, Schmid said, the results do suggest that even modest sleep restriction — so common in today’s society — reduces physical activity, while hormones and appetite are “less affected.”