By John Salak –
A century of weight management wisdom maintains that overeating is the primary cause of weight gain, especially when coupled with today’s increasingly sedentary lifestyle. Tough to argue with this “energy balance” since the Centers for Disease Control and Prevention (CDC) shows that more than 40 percent of American adults flirt with obesity, which brings with it the risk of heart disease, stroke, type 2 diabetes and even certain types of cancer.
But the authors of a new study are challenging conventional wisdom. They argue that even though public health officials have pleaded with people for decades to eat less and exercise more, the rise of obesity and related diseases had still risen steadily. Hence, maybe there is something wrong, a flaw, in the eat-less, exercise more manifesto.
These researchers maintain that a different weight management approach using the carbohydrate-insulin model is a better way to understand and combat obesity. Affectively, they report that all calories are not alike. Some foods, in fact, generate hormonal responses that fundamentally change a person’s metabolism, driving fat storage, weight gain and obesity.
The carbohydrate-insulin model these researchers support claims the current obesity epidemic is driven by modern dietary patterns that result in people eating foods with a high glycemic load that holds processed, rapidly digestible carbohydrates. These carbohydrates cause the body to increase insulin secretion while suppressing glucagon secretion. This leads fat cells to store more calories, which leaves fewer calories around to fuel muscles and other metabolically active tissues.
The debilitating chain reaction doesn’t end there. With fewer calories around to fuel necessary functions, the brain thinks the body isn’t getting enough energy, which then sets up feelings of hunger. To make matters worse, an individual’s metabolism may then shift to conserve fuel. This means people may continue to feel hungry even as they gain fat.
If the researchers are correct, weight management and obesity treatment could be in for a radical shift. Instead of urging people to munch less, which has a lousy track record for shedding pounds, this new model would focus more on what they eat, according to Dr. David Ludwig, the study’s lead author.
“Reducing consumption of the rapidly digestible carbohydrates that flooded the food supply during the low-fat diet era lessens the underlying drive to store body fat,” he explained. “As a result, people may lose weight with less hunger and struggle.”
Admittedly, the researchers’ work isn’t finished as they acknowledged conclusive tests need to be conducted using both models. But they are confident their work to date can help reshape weight management.
Ludwig’s team wasn’t the only group to release significant work on obesity. Scientists from McMaster University in Canada reported recently that chlorpyrifos, a commonly used pesticide, also may be helping to advance the global obesity epidemic.
While the pesticide is banned on foods in Canada, it is widely used on fruits and vegetables in other parts of the world and the McMaster research team found that it slowed down the ability of mice to burn calories in brown fat, causing them to gain weight and become obese.
If this process, known as diet-induced thermogenesis, holds true for people, it could help explain the rising levels of obesity worldwide.
“Lifestyle changes around diet and exercise rarely lead to sustained weight loss. We think part of the problem may be this intrinsic dialing back of the metabolic furnace by chlorpyrifos,” said Gregory Steinberg, professor of medicine and co-director of the Centre for Metabolism, Obesity, and Diabetes Research at McMaster.
He added that chlorpyrifos would only need to inhibit energy use in brown fat by 40 calories every day to trigger obesity in adults through an extra five pounds of weight gain every year.
The research team added that even in countries that ban the use of chlorpyrifos on foods grown domestically, it is likely to be on some imported foods. As a result, it recommended washing imported fruits and vegetables thoroughly.
