By Ariel Zisman, M.D
For the first time, the World watch Institute reports, there are almost as many overfed and overweight people in the world as those who are underfed. In 2010, we continued to rank as the world’s fattest developed nation, with an obesity rate of more than double that of many European nations. By 2015, four out of 10 Americans may be obese.
How did Americans get so fat? Where did we go wrong? The most widely used method to determine obesity is the body mass index (BMI), calculated from a person’s weight and height (BMI = weight/height2, in kg/m2), and provides a reasonable indicator of body fatness and weight categories that may lead to health problems.
The statistics are alarming. Recent reports from the Center for Disease Control and Prevention (CDC) reveal that the rates of obesity continue to rise: 68 percent of American adults are overweight, and 34 percent are obese; roughly one in three children and adolescents is overweight. While only 4 percent of children were considered obese in 1982, now almost 30 percent are. In the last 30 years, overweight rates have doubled among children and tripled among adolescents, and childhood obesity often persists into adulthood. In fact, many children are diagnosed with Type 2 diabetes, a condition that was previously considered a rarity in this age group. Obesity is a leading preventable cause of death worldwide and authorities view it as one of the most serious health problems of the 21st century. Why do we care? Both overweight and obesity can make it more likely that the person will develop serious medical conditions, such as diabetes, high blood pressure, heart disease, stroke, gallstones, fatty liver, high cholesterol, gout, sleep apnea, many types of cancer (in particular colon, breast and endometrial), and even early death.
At an individual level, a combination of chronic excessive caloric intake and insufficient physical activity is thought to explain most cases of obesity. A limited number of cases are due primarily to genetic disorders, specific medical reasons, or psychiatric illness. However, because of the complexity of the neuroendocrine and metabolic systems that control how much energy we eat, we store and we burn up, it has been difficult to pinpoint the major factor(s) responsible for obesity in humans.
So in one sense, the obesity crisis is the result of simple math. It’s a calories in, calories out calculation. The “First Law of Fat” says that anything you eat beyond your immediate need for energy converts to fat. Americans now consume an average of 2,700 calories per day, about 500 calories more than they did 40 years ago. However, some people do gain weight more easily than others, highlighting the influence of genes on the propensity for obesity. Other possible contributors to the recent population increase of obesity are insufficient sleep, chronic stress, exposure to endocrine disruptors (environmental pollutants that interfere with metabolism, appetite or satiety), increased use of medications that can cause weight gain (for example, medications for diabetes, depression or other psychiatric illnesses), and pregnancy at a later age (which may cause propensity to obesity in children).
In the United States, consumption of fast-food meals tripled, and caloric intake from these meals quadrupled between 1977 and 2000. We live in a toxic environment with too many fast food offerings around us. Bad food is cheap, heavily promoted and engineered to taste good. Healthy food is harder to get, not promoted and expensive. If you came down from a different planet and saw all this, what else would you predict except an obesity epidemic? But the battle on obesity is not lost. While the solution will require involvement of the society in general, regulations on the food industry, marketing and labeling, changes in nutrition and fitness education, school meal programs, etc., there are many things that can and must be done at an individual level. Proper eating and the regular performance of physical exercise are the mainstays of prevention and treatment of obesity. We need to improve the quality of our diet by reducing the consumption of energy-dense foods and by increasing the intake of dietary fiber.
If you need to lose weight, you must reduce the calories consumed (yes to follow a diet) and increase your energy expenditure (you guessed right: exercise!) There is no magic, only a bit of effort, the willingness to become healthier and proper guidance are necessary.