Many overweight adults can't seem to lose weight no matter what they try. The problem may not lie in their calorie counts but their very cells: Increasing numbers of Americans, leading nutritionists say, are insulin-resistant. That is, their bodies no longer properly use the hormone insulin to process the food that's eaten. Net result: The body hangs on tight to the fat that's already there.
A stubborn inability to lose weight because of insulin resistance is a complicated but common problem, says integrative nutritionist Beth Reardon, director of nutrition for Duke Integrative Medicine, part of the Duke University Health System. If you're fighting the scale, she adds, you may be among the 79 million American adults who have or are heading toward prediabetes, a syndrome of insulin-related challenges that usually leads to diabetes unless health changes are made.
In 2010, 1.9 million new cases of full-blown diabetes were diagnosed, according to the Centers for Disease Control. Indeed, diabetes and obesity are so related that some health experts have coined the descriptor diabesity.
Why You May Not Be Losing Weight
When we eat, the food is broken down into glucose (blood sugar), the body's main energy source. As blood flows through the pancreas, this organ detects the high levels of glucose and knows to release insulin, a hormone that it produces in order to allow the cells throughout the body to use the glucose. The cells have insulin receptors that allow glucose to enter. Then the cell either uses the glucose to make energy right away or stores it as a future energy source.
For some people, though, this system has gone haywire. The cells' insulin receptors have pretty much stopped acknowledging the insulin, which means the cells don't get the glucose. Instead, the glucose builds up in the blood, where the pancreas notes the escalating glucose levels and pumps out still more insulin in response.
"The cells are starving because the fuel they need isn't being absorbed at the insulin receptor site on the cell," Reardon says.
So what does the body do in response? It hangs on fiercely to the energy stores -- fat -- it already has. And any glucose the cells do manage to absorb goes straight into storage -- as still more fat.
You can't lose weight because your body is in survival mode.
This whole process builds slowly over years. What triggers it in the first place? Experts believe that for many people, the problem stems mainly from a diet overloaded with simple carbohydrates -- bread, pasta, pizza, pastries, crackers, chips and other processed snack foods, sweetened beverages, corn syrup, and other quickly-digested sugars and starches. In other words: the typical modern Western diet. Faced with constant, quick hits of easily digested energy sources, the pancreas keeps pumping out insulin to help the energy get into the cells, but the overwhelmed cells finally say, "Enough!" and stop paying attention.
Warning Signs of Insulin Resistance
This kind of stubborn fat doesn't happen in isolation. The difficulty losing weight almost always occurs along with most of the following warning signs that you may be insulin resistant:
Weight gain centered in the middle -- "belly fat" -- measuring greater than 40 inches for a man or 35 inches for a woman
A body mass index (BMI) in the overweight or obese zones
A tendency to crave carbohydrates (as the starving cells tell the brain to give you more, more, more!)
Frequent fatigue, especially right after eating
Foggy thinking (because glucose is the preferred energy source for the brain, and the brain's cells, too, are starving for glucose)
High glucose levels, as measured by an oral glucose tolerance test (OGTT) or fasting plasma glucose test (FPG) (The latter test isn't routinely offered in clinical practices.)
High fasting and timed insulin levels, which are measured as part of the OGTT
High blood pressure (135/85 or above)
Low levels of "good" HDL cholesterol (below 40 mg/Dl for a man, below 50 mg/Dl for a woman)
High triglyceride levels (150 mg/Dl or above)
Together, this constellation of symptoms is known as "metabolic syndrome," or "syndrome X." Even though there seems to be a genetic predisposition for some people, insulin resistance that leads to type 2 diabetes largely depends on lifestyle. "Anyone can eat his or her way to diabetes," Reardon says. "Diabetes is particularly lifestyle and diet-driven."
-- From the NET
Nandakumar
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