The number of overweight and obese has been remarkably stable for the past several years at about two-thirds of the adult population. This strongly suggests that these Americans are genetically prone to gain weight under the right dietary circumstances. Yet a greater number of adults are moving from a classification of being simply overweight to being labeled as obese. This is a strong indication that those who are genetically predisposed to weight gain are becoming fatter. According to the Centers for Disease Control, only three states in 2007 had more than 30 percent of the adult population classified as obese. In only two years, the number of states that have more than 30 percent obesity in adult populations had increased to nine. That's a 300 percent increase in two years!
One new suspect in our growing obesity crisis may be caffeinated coffee. It has been known for a long time that a high-fat meal increases blood sugar as well as maintains high levels of triglycerides (1). A new study from the University of Guelph found that consuming a high-fat meal increased blood sugar by more than 30 percent when giving a standard glucose tolerance test five hours later (2). Adding the equivalent of two cups of coffee more than doubled this increase in blood-sugar levels five hours after a high-fat meal.
The implication is that a constant diet of high-fat foods and a lot of coffee will accelerate the development of insulin resistance. When this occurs, the pancreas is forced to release more insulin to help reduce blood sugar levels. Unfortunately, it is excess insulin that makes you fat and keeps you fat.
The controversy over caffeine has continued for more than 100 years. The first instance occurred in a trial in the early part of the 20th century at which the U.S. government sued Coca-Cola for adulterating a food by adding caffeine to a soft drink. (Fortunately for Coca-Cola, the company had removed the coca extracts containing cocaine several years earlier). In a trial similar to the Scopes trial on evolution that would be held 15 years later in the same court system, the testimony was highly charged on both sides. The local judge dismissed the case, but the government continued it for many years in various appeals courts until the case was settled with a no-contest plea (3).
Now a new call for limits on caffeine was presented in a recent article in the Journal of the American Medical Association (4). Maybe with more research we will find that caffeine may be another factor for those who are genetically predisposed to gain weight to become fatter than ever.
- Tushuizen ME, Nieuwland R, Scheffer PG, Sturk A, Heine RJ, and Diamant M. “Two consecutive high-fat meals affect endothelial-dependent vasodilation, oxidative stress and cellular microparticles in healthy men.” J Thromb Haemost 4: 1003-1010 (2006).
- Beaudoin MS, Robinson LE, and Graham TE. “An oral lipid challenge and acute intake of caffeinated coffee additively decrease glucose tolerance in healthy men.” J Nutrition 141: 574-581 (2011).
- Carpenter M. “A century later, jury's still out on caffeine limits.” New York Times. March 28, 2011.
- Arria A and O'Brien MC. “The ‘high' risk of energy drinks.” JAMA 305: 600-601 (2011).