When normal isn’t healthy
The typical American doesn’t get enough exercise, eats too much fat and sugar and too few vegetables and is overweight. Unfortunately, we have come to consider this combination as “normal.” While this situation may be typical, it is definitely not normal.
For most measures of health, a normal value is consistent with good health. A “normal” blood pressure is in a range that is associated with a low risk of stroke, for example. Someone with LDL (bad) cholesterol that is considered “above normal” has a greater risk of heart attack than a person with a normal LDL value.
But for many health indicators, having a normal value is not the norm. According to the most recent recommendations, a normal blood pressure is less than 120/80 mmHg. However, nearly 60 percent of adults have a blood pressure that is above normal, meaning they have hypertension or prehypertension. A person who has a body mass index (BMI) in the normal range, between 18.5 and 24.9 kg/m2, is considered to be at a healthy body weight. But two-thirds of adults are overweight, with a BMI above the normal range.
The problem is that the term “normal” is frequently used to refer to what is typical, rather than what is healthy. Obesity is so common that a person who is at a healthy weight may look out of place. So many people look for ways to avoid physical activity that a person who walks instead of drives is considered abnormal. The person who comes away from a buffet with a less-than-full plate or who has a salad for dinner often gets strange looks. One of the reasons that people get noticed for doing these things is because they stand out from the crowd.
In reality, though, many of the health behaviors we consider to be abnormal – regular exercise, a healthy diet or a lean physique – are, historically, completely normal. Until relatively recently, most everyone was active much of the day and spent little time being sedentary. Likewise, the consumption of the processed foods that are such a big part of our current diet was rare even a few decades ago.
It is likely that, by considering unhealthy behaviors to be normal, we have created a situation that discourages people from adopting a healthy lifestyle. As anyone who has tried to change their health habits knows, it can be a challenge, especially if everyone else maintains their typical eating and activity pattern. It’s not easy to be “the one” who only eats healthy food or who takes time to exercise every day.
Maybe we need to redefine normal health behaviors to reflect what is healthy rather than what is most common. When walking or biking rather than driving becomes the norm, there will be greater incentive to provide safe places for pedestrians and cyclists to travel. When a healthy diet is considered normal, it is more likely that restaurants will offer more nutritious options. In the end, we would all benefit from changing our definition of normal. And a normal diet and activity pattern will go a long way to promoting a normal BMI, blood pressure, and cholesterol.
Brian Parr, Ph.D., is an associate professor in the Department of Exercise and Sports Science at USC Aiken where he teaches courses in exercise physiology, nutrition and health behavior. He is a member of the American College of Sports Medicine and is an ACSM certified clinical exercise specialist; his research focuses on physical activity in weight management and the impact of the environment on activity and diet. Parr lives in Aiken with his wife, Laura, and sons Noah, Owen and Simon.