The Truth About Fat
Everything you need to know about fat, including an explanation of which is worse -- belly fat or thigh fat.
White Fat
White fat is much more plentiful than brown, experts agree. The job of white fat is to store energy and produce hormones that are then secreted into the bloodstream.
Small fat cells produce a "good guy" hormone called adiponectin, which makes the liver and muscles sensitive to the hormone insulin, in the process making us less susceptible to diabetes and heart disease.
When people become fat, the production of adiponectin slows down or shuts down, setting them up for disease, according to Fried and others.
Subcutaneous Fat
Subcutaneous fat is found directly under the skin. It's the fat that's measured using skin-fold calipers to estimate your total body fat.
In terms of overall health, subcutaneous fat in the thighs and buttocks, for instance, may not be as bad and may have some potential benefits, says Cypess. "It may not cause as many problems" as other types of fat, specifically the deeper, visceral fat, he says.
But subcutaneous fat cells on the belly may be another story, says Fried. There's emerging evidence that the danger of big bellies lies not only in the deep visceral fat but also the subcutaneous fat.
Visceral Fat
Visceral or "deep" fat wraps around the inner organs and spells trouble for your health. How do you know if you have it? "If you have a large waist or belly, of course you have visceral fat," Whitmer says. Visceral fat drives up your risk for diabetes, heart disease, stroke, and even dementia.
Visceral fat is thought to play a larger role in insulin resistance -- which boosts risk of diabetes -- than other fat, Whitmer tells WebMD. It's not clear why, but it could explain or partially explain why visceral fat is a health risk.
Whitmer investigated the link between visceral fat and dementia. In a study, she evaluated the records of more than 6,500 members of Kaiser Permanente of Northern California, a large health maintenance organization, for an average of 36 years, from the time they were in their 40s until they were in their 70s.
The records included details on height, weight, and belly diameter -- a reflection of the amount of visceral fat. Those with the biggest bellies had a higher risk of dementia than those with smaller bellies. The link was true even for people with excess belly fat but overall of normal weight.
She doesn't know why belly fat and dementia are linked, but speculates that substances such as leptin, a hormone released by the belly fat, may have some adverse effect on the brain. Leptin plays a role in appetite regulation but also in learning and memory.
Belly Fat
Belly fat has gotten a mostly deserved reputation as an unhealthy fat. "Understand that belly fat is both visceral and subcutaneous," says Kristen Gill Hairston, MD, MPH, an assistant professor of medicine at Wake Forest University School of Medicine, Winston-Salem, N.C. "We don't have a perfect way yet to determine which [of belly fat] is subcutaneous or visceral, except by CT scan, but that's not cost-effective."
Belly Fat continued...
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But if you've got an oversize belly, figuring out how much is visceral and how much is subcutaneous isn't as important as recognizing a big belly is unhealthy, she says. How big is too big? Women with a waist circumference more than 35 inches and men with a waist circumference more than 40 inches are at increased disease risk.
Abdominal fat is viewed as a bigger health risk than hip or thigh fat, Whitmer and other experts say. And that could mean having a worse effect on insulin resistance, boosting the risk of diabetes, and a worse effect on blood lipids, boosting heart and stroke risks.
Thigh Fat, Buttocks Fat
While men tend to accumulate fat in the belly, it's no secret women, especially if "pear-shaped," accumulate it in their thighs and buttocks.
Unsightliness aside, emerging evidence suggests that pear-shaped women are protected from metabolic disease compared to big-bellied people, says Fried.
"Thigh fat and butt fat might be good," she says, referring to that area's stores of subcutaneous fat. But the benefit of women being pear shaped may stop at menopause, when women tend to deposit more fat in the abdomen.
Weight Loss and Fat Loss
So when you lose weight, what kind or kinds of fat do you shed? "You're losing white fat," Fried tells WebMD. "People tend to lose evenly all over."
The results change a bit, however, if you add workouts to your calorie reduction, she says. "If you exercise plus diet you will tend to lose slightly more visceral fat from your belly."
"We're at an exciting point in science," says Whitmer, echoing the input from other scientists in the field.
Whitmer and others expect more discoveries about fat of all types to be made in the near future.
http://www.webmd.com/diet/features/the-t...fat?page=2
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Quote:Small fat cells produce a "good guy" hormone called adiponectin, which makes the liver and muscles sensitive to the hormone insulin, in the process making us less susceptible to diabetes and heart disease.
Adiponectin and Diet
Having low blood adiponectin levels increases the risk of developing diabetes, and it may also be associated with heart disease and even some types of cancer. The composition of your diet and the amount of fatty tissue that you have can influence circulating adiponectin levels. Adhering to a healthy diet containing plenty of plant-based foods, dietary fiber and ocean fish may help elevate low blood adiponectin levels.
Importance of Adiponectin
Adiponectin is a small protein that fat cells produce and secrete into the bloodstream. Adiponectin is also a hormone. It binds with specific receptors on the surface of tissue cells and produces some known metabolic effects. For example, adiponectin increases the use of fatty acids for fuel, and it enhances insulin sensitivity in tissues such as the liver and muscles.
These effects facilitate blood glucose transport into tissue cells. Obesity can lower adiponectin production, and low circulating adiponectin levels are associated with type-2 diabetes. Although still a subject under investigation, adiponectin may also help protect against blood vessel disease, heart attack and stroke.
http://www.livestrong.com/article/313879...-and-diet/
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