Look around. It’s easy to see that the general population is getting heavier. According to the U.S. Centers for Disease Control and Prevention, two-thirds of Americans are now overweight or obese.

Look around. It’s easy to see that the general population is getting heavier. According to the U.S. Centers for Disease Control and Prevention, two-thirds of Americans are now overweight or obese. We know that obesity leads to chronic diseases, costing hundreds of billions of dollars to treat. Obesity is now the second leading cause of preventable death. (Smoking is still first). The average adult American is 25 pounds heavier than in 1960. So what has happened during the past few decades to account for this current epidemic of obesity? There seems to be plenty of blame to go around, but is any of it justified?

Sugar, especially high fructose corn syrup, is often vilified as the cause of obesity. But according to the U.S. Department of Agriculture, most of the 450 extra calories we now eat (compared to 1970), are coming from fats and oils, not sugar. True, sugar is a source of empty calories, but it certainly can’t be blamed as the sole cause of obesity.

Maybe it’s the “big food industries”? After all, they have made processed and fast foods cheap, convenient, readily available and somewhat addictive. Fast food restaurants now blanket the landscape, making access to cheap, high calorie, low-nutrient foods easier than ever. Food companies spend billions of dollars in advertising to get us to desire and buy their food. It seems to be effective.

Portion sizes have increased throughout the years, and Americans love bargains. Who doesn’t want more for their money? Restaurants can make customers happy by serving large portions with little increase in cost. People tend to eat what is served, believing that this is an appropriate amount. This has trained us to think these oversized portions are normal. So now we eat more when we are at home, too.

More women work outside the home now. This means fewer family meals prepared at home. The U.S. Department of Agriculture estimates 20 percent of our calories come from meals eaten outside the home. This is triple what it was in 1977. Eating one meal away from home per week equals a 2 pound weight gain per year. We eat out an average of five meals a week. You do the math.

Food temptations are everywhere. Almost every store has some sort of food or drink available at the checkout to tempt us, even clothing stores. Convenience stores and gas stations are on every block. We snack 100 percent more than we did in the 1970s, according to a Harvard University study. We snack because we are bored. We nibble and sip all day long at our desks. We buy decadent treats because we work hard and we deserve them. We can barely leave the house without a water bottle or soda and a snack just in case we get hungry. We think about a food and can instantly gratify that desire with just a short trip to the nearest store. If you had to scrub and cut potatoes then fry them every time you craved French fries, you’d probably get over that craving rather quickly. Instead, we can just drive through the nearest fast food restaurant.

Stress may definitely play a factor in obesity. We work too hard, take too few vacations, get too little sleep, worry about the horrible nightly news stories and eat irregular meals. Studies show that stress hormones can cause weight gain, as can lack of sleep.

Some critics blame the overproduction of crops due to government subsidies as the cause of obesity. Excess grain is either processed into food for humans or fed to animals for meat production. It is true that we produce more food than our country can possibly eat, but is this really the cause of our obesity? No one is force feeding us.

Maybe it’s just evolution. After all, our bodies are programmed to store calories when food is plentiful. The problem is, it doesn’t look like we are in risk of famine any time soon to balance out the feast. Dieting just aggravates the obesity problem. When we cut calories, we will lose weight. But, now our body uses fewer calories and we have to continue to eat less to maintain the weight loss. Successful weight loss means that it takes fewer calories to stay at a lower weight than if you were never overweight. Repeated dieting only makes this worse.

Thin people like to blame the obese themselves: fat people just lack self-control. But, we all know people who eat healthy foods, limit how much they eat, get regular exercise and still are overweight. I also know thin people who eat junk, drink too much soda and don’t exercise.

We move our bodies less. Our jobs don’t require physical labor or even much movement. Our kids don’t play outside, and physical education is not offered in many schools. We don’t walk anywhere. A Gallup poll for July 2013 showed that just 52 percent of Americans get 30 minutes of exercise or more per week. That amount of exercise is good for your overall health, but it is not enough to lose weight.

We are exposed to more education and are more knowledgeable about our health, diet and weight than ever before. But, this seems to have little impact on our own weight. We want a quick fix. Some feel that the government should implement bans on things like soda and junk foods, but it’s likely that manufacturers will just find a way around these regulations and still supply our appetites.

In my opinion, the root of the obesity problem is simple: We just eat too much. You buy the food, you put it on your plate, and only you can choose whether to eat it.

Anita Marlay, R.D., L.D., is a dietitian in the cardiac rehab department at Lake Regional Health System in Osage Beach, Mo.