Credit: TMS illustration/Donna Grethen/

New York City Mayor Michael Bloomberg's proposal to ban oversized sugary drinks met with a roar of protest when it was announced last week. But the real issue is not about interfering with personal rights. It's not even just about curbing calories. It's about taking a stand to halt what is becoming a national public health disaster: the twin epidemics of obesity and diabetes. We are becoming a nation of oversized people.

Current estimates are that more than 200 million Americans -- two-thirds -- are overweight, meaning they have a body mass index of 25 or greater. BMI is calculated from a person's height and weight, and is used by population health organizations, researchers and medical clinicians as an indicator of body fatness. For example, a 5-foot-10 person weighing 200 pounds would have a BMI of 28.7 and would be considered overweight. Someone who is 5-foot-4 and 167 pounds would have the same BMI.

The proportion of those who have already tipped the scale into the dangerous territory of obesity -- a BMI of 30 or greater -- is an astounding one-third of the U.S. population, according to the Centers for Disease Control and Prevention. And, it's not only adults who are gaining weight at a frightening pace: The percentage of children who are overweight in this country has more than tripled since the 1970s.

Obesity brings with it a host of problems. When compared with normal-weight individuals (those with a BMI of 18.5 to 24.9), the obese have a significantly increased risk of disease, including coronary artery disease, high blood pressure, stroke, high cholesterol, liver and gallbladder problems, and osteoarthritis (degenerative joint disease) and many others. Moreover, studies show that being obese significantly increases the risk of death from all causes.

So, what do those sugary drinks have to do with all this doom and gloom? According to Harvard researchers who published their findings in 2010, drinking just one or two 12-ounce sugar-sweetened drinks each day increases the risk of diabetes by 26 percent. The large drink size at many fast-food restaurants is 32 ounces. Given that these soft drinks constitute the largest single food source of calories in the U.S. diet today, it's no wonder that the rates of obesity and diabetes have risen in tandem with the rates of sugar-sweetened beverage consumption.

The unfortunate truth is that the larger you become, the more likely it is that you will be diagnosed with diabetes. Nearly 26 million American men, women and children already have been -- more than 8 percent of the total population. If the trend continues, one-third of the population will be diabetic by midcentury. The connection is painfully clear: More sugary calories consumed leads to heavier people. And heavier people are significantly more likely to develop type 2 diabetes, with all its devastating complications. More than 60 percent of non-traumatic lower-limb amputations are performed on people with diabetes, for example. And diabetes is either a cause or a contributing factor in more than 200,000 deaths each year in the United States, according to death certificate data.

The sheer scale of human suffering should be enough to convince responsible officials of the need to act. But if pain and disability don't convey the urgency of the problem, how about the financial costs?

Today, we are spending about $2.8 trillion on health care annually. The American Diabetes Association estimates that the annual medical costs associated with managing those already diagnosed with diabetes, together with the indirect costs -- disability, work loss, premature death -- come to more than $170 billion. Add this to the cost of treating and managing all the chronic diseases in the United States, many of which are clearly linked to obesity, and the total is close to $2 trillion. With more than 70 percent of our health care spending already going toward chronic diseases, can we really afford to face a future in which even more health-care dollars will be spent on obesity and its complications?

If the proposed ban on sugary beverages of more than 16 ounces goes through, some will get around it by purchasing two (or more) smaller-sized drinks. But many others may think twice -- and choose a healthier alternative. An important step will have been taken toward changing the behaviors that are contributing to such dangerous -- and expensive -- ill-health.