Excess body fat accelerates aging and then kills us. Essentially, obesity is an accelerated form of aging and obesity predisposes us to diseases that are common in old age. Why? Obesity reproduces many of the same metabolic conditions that underlie the aging process itself. How? Fat cells produce inflammation; the more you have the more inflammation your body needs to control. Consequently, by elevating the level of inflammatory proteins in the body, obesity increases the risk of breast, colon and lung cancers. In addition, these same inflammatory proteins contribute to brain shrinkage, cognitive decline and an increased risk of depression.
I was recently honored by an invitation to give a TED talk on this idea. The video is available here. http://www.youtube.com/watch?v=4SvkaK2Al0o&feature=plcp
Researchers from the Fred Hutchinson Cancer Research Center in Seattle recently published a report in the journal Cancer Research that investigated whether diet or exercise most effectively modified the levels of inflammatory proteins in overweight or obese women. After twelve months the authors concluded that the greatest weight loss and most significant reduction in the level of inflammatory proteins reductions come only from dieting. The women who participated in an exercise-only program showed no reduction in inflammatory proteins!
Why is exercising so inefficient? The answer lies in understanding how our bodies evolved and the priorities established during this evolution. Our gastrointestinal system uses nearly 70% of all of the energy you consume just to make the remaining 30% available to the rest of your body. Your brain uses about 14% of the available consumed energy, and your other organs that allow you to reproduce and move around your environment (including your muscles and bones) utilize only about 15%. As you can see, very little energy is left over for other tasks in the body. These percentages give you some idea of the priorities—sex and mobility—that billions of years of evolution have set for your body to achieve. Unless you’re a marathon runner or swimmer, the activity of our musculature is not a big player in calorie consumption. Simply stated, the results of this study confirm that caloric restriction is the only valid, scientifically proven dietary intervention that has been shown to slow the aging process, reduce the risk of cancer and improve health. It’s also much cheaper – you’ll save money on eating so much food and paying for expensive gym memberships.
The good news is that the consequences of inflammation due to body fat are likely to develop slowly and require many years to be fully expressed. However, the sooner one loses the fat the sooner the brain and body can begin to recover. This risk factor is preventable!
© Gary L. Wenk, Ph.D., author of Your Brain on Food (Oxford, 2010)