 Taking personal responsibility for our health is one of the most important things we can do. Regular exercise, not smoking and eating a healthy diet, can help prevent and even reverse some of the most common diseases. And most people know this, so why don't they eat healthier? Watch the video to find out. Yes, media messages surrounding nutrition are often inconsistent and confusing, but many Americans know what constitutes a healthy diet. Does anyone really think drinking brown carbonated sugar water is good for them? At issue is that they don't appear to be translating their knowledge into action. There are a number of reasons people have such difficulty changing their dietary behaviors, while ignorance and confusion may play a part. The motivation to change is likely much more important. Certainly we are living in a world that pushes us to eat whatever we want, regardless of the long-term consequences, but one of the major problems in getting people to change their behavior is the need to get them to recognize the need to change. For example, if you ask people how much meat they eat, or how much greasy food, eggs, sweets, alcohol, butter, they claim to be eating less than the average person. So if people think they're at less risk than others, they may dismiss advice to eat more healthfully, thinking that they already eat healthier. Maybe they are? No, people rated their own eating behavior as healthier on average, even when their actual eating habits were terrible. For this reason, maybe health-promoting campaigns need to make people aware of how badly they're eating. But when you do that, a strange thing happens. If you challenge people with the reality if the average person actually eats, they change their answer to make themselves appear as though they're still healthier than average. When people's favorable comparisons on risky behaviors are threatened, they not only reduce their estimates of how often they engage in those behaviors, oh, I don't eat that much meat, but they also attenuate the significance of those behaviors. Meat's not that bad for you anyway. It's the same personal fable that smokers tell themselves. Studies show that smokers have a strong tendency to underestimate all smoking-related risks, developing a series of illusions and false beliefs to support their choice to keep on smoking. Why do so many people continue to light up in spite of smoking's harmful effects to their health? For many of the same reasons, people continue to eat unhealthy food. First, they convince themselves that they are less at risk than others who engage in the same behavior. And in addition to this optimism bias, smokers' underrest made the extent to which smoking elevates lung cancer risk, thinking two-pack-a-day smokers only have like five times the risk of getting lung cancer when their actual risk is 20-fold higher. And anyway, many smokers believe lung cancer is mainly determined by one's genes. Many food-related hazards share the same optimistic bias, such as heart attacks and heart disease, our number one killer, obesity, diabetes, and all the rest. People are often quite ingenious in finding reasons for believing that their own risk is less than the risk faced by their peers, so maybe public health advocates need to be just as ingenious in understanding the origins of this unrealistic optimism and in finding approaches to help people gain a more accurate picture of their own vulnerability. All sorts of work is being done trying to reduce or eliminate this bias, but we must consider the possibility that reductions in optimistic bias may lead to reductions in self-esteem and psychological well-being if people start to realize just how much risk they truly face and how much they have themselves to blame. This reminds me of the tightrope wire health professionals have to walk telling people how much power we all have over getting cancer. This is the off-sided paper that calculated that we may be able to prevent approximately 90% of human cancers, but by present trends, the researchers talking about present trends of the 1960s when the paper was published. They remain true to this day, though, about a half century later. Genetic factors are not the major causes of chronic diseases. Using identical twins to see how much was really just in your genes of all the chronic diseases they looked at, cancers had the lowest genetic component. Again, only about 10% attributable to bad genes. What runs in families is bad habits. But when you go out there and tell everyone the good news about how much power we have over not getting cancer, what about the people who already have it? When people are diagnosed with cancer, they often ask, why me? Did I do something wrong? Is this my fault? So you can imagine how the message of, well, yeah, kind of, could be destructive for patients or survivors. In other words, a message that is intended to empower people in a prevention context could just make cancer victims feel guilty. But the truth is still the truth, no matter how difficult it may be. So what we have to do is try to guide patients to switch from feelings of guilt to a responsibility approach. They have personal control. They can make different choices from then on. We need to give them a sense of agency in their life. Better, though, to try to take those steps before you get cancer.