Redundant Pathways of Obesity

Treatments Should Target Multiple Pathways (Part 1)

June 30, 2010

Ken Fujioka, MD

It is impossible today to turn on the news without hearing something about obesity. Obesity continues to grow because of the mismatch between our calorie laden environment versus our genetic predisposition to gain weight when adequate calories are available. Not all, but most humans (75% to 80%), are designed to be over overweight or obese. The turning point was probably the introduction of agriculture and eventually the very high calorie diet that we now have at our disposal on a daily basis. Outside of increased availability of caloric dense foods, our physical activity has also decreased dramatically. Prior to the advent of improved technology and city planning, we used our legs to go from point A to point B.  Now it appears that we drive everywhere and often we take the elevator instead of walking up the stairs. Conversely, when individuals with genes that are predisposed to gain weight are placed in a lifestyle that requires increased labor (e.g., Amish men), the genetics of weight gain are actually overridden and these Amish men do not exhibit obese tendencies.

Along with weight gain, there are a number of rather severe chronic diseases that are linked with obesity, as humans are simply not meant to carry the additional adipose (fat) tissue. Most of these diseases are well known, such as hypertension, dyslipidemia, diabetes, and coronary heart disease. Unfortunately, cancer rates can also go up dramatically with excess weight. Thus, it is no surprise that obesity is a very costly health problem. The most difficult part of recognizing obesity as a serious problem is that we currently have a very limited number of treatments that are proven to be effective.

There is no question that diet and exercise are the most cost efficient way to tackle the issue of obesity. But if you talk to an obese patient about their weight loss experience, typically they will be unhappy to report their inability to get to that desired “goal weight.” Additionally, once the weight is lost, it’s difficult to maintain that loss for any significant period of time. 

Over the past decade, more physicians and patients have started to recognize obesity as a disease (not just a vanity issue), yet it is still under-treated as a “medical problem.” The reason for this is complicated, but is in part, due to the social stigma surrounding obesity — many patients and physicians still feel that it is simply a “will power” issue or lifestyle choice. Thus, prescribing medication is often viewed as “an easy way out.” This is despite data showing that the body makes rather impressive metabolic adjustments in reaction to 5% to 10% weight loss. Not only does the brain think about food more with increased weight loss, but it will decrease a person’s metabolism at a rate lower than expected in order to fight off weight loss. Essentially, the brain fights to keep a “set point weight,” making it difficult to lose and maintain significant weight loss. The scary aspect of this medical epidemic is that we are seeing chronic diseases that usually manifest later in life starting to show up in younger and younger patients as obesity prevalence rates in kids continue to increase. Today we are seeing more teenagers with diseases such as type 2 diabetes, hypertension, fatty liver disease, and heart disease. The problem is that we do not have a clear understanding of what this impact is going to be twenty years down the line. Further research will need to be done to not only better understand the evolving epidemiology and health impact of obesity but to fully understand a better way to treat the disease.

This perspective will be continued the week of July 5th.

Dr. Fujioka is the Director of the Nutrition and Metabolic Research Center, and a member of the Division of Diabetes and Endocrinology, at the Scripps Clinic - Del Mar in San Diego, California.

For more related articles, click Obesity Perspectives.