In an article published in early October in his syndicated column, "Stone Age Doc," Dr. Phillip J. Goscienski wrote that grains, sugar, and dairy products food sources not used by humans hundreds of thousands of years ago when our present "body chemistry" was being formed now comprise more than 70 percent of the world's caloric intake.

Later in the article, Goscienski declared that only 30 percent of Americans are of normal weight. In other words, 70 percent of Americans are overweight the same percentage of calories consumed that are "genetically inappropriate" according to the guidelines of any Paleolithic diet.

Can it be coincidence that the two numbers match? Is this predominance of so-called "new" foods causing what Goscienski calls our "thrifty gene" to store them as the excess fat that eventually creates heart disease, stroke, diabetes, and cancer?

Possibly. But don't look to this column to provide a definitive answer.

That's because you don't need to know definitively what causes heart disease, stroke, diabetes, and cancer to greatly lower your chances of contracting them. Similarly, you don't need to know what causes 65 percent of adult Pennsylvanians to be either overweight or obese, according to a CDC study released in 2012, to be part of the 35 percent that's not.

One of the things you do need is an awareness of how important eating properly really is. Goscienski makes this apparent when he writes that type 2 diabetes used to develop in people who ate the wrong foods in "late middle age [yet it] now is common during adolescence."

Another thing you need is to really think about what you personally believe is the key to causing obesity. A recent study published in Psychological Science suggests that your opinion on this matter goes a long way in determining your body mass index.

Brent McFerran of the Ross School of Business at the University of Michigan worked with Anirban Mukhopadhyay of Hong Kong University of Science and Technology and administered an online survey to participants. From this, two distinct thoughts about obesity emerged.

While many believed poor diet was the cause of the burgeoning obesity epidemic, others placed the blame on a lack of exercise. Interestingly enough, the belief that genetics was creating this, a belief that to some degree mitigates the fault of being fat from individuals, did not receive serious consideration.

The researchers then replicated the original survey in five different countries to see if the pattern would continue. It did and another just as significant emerged.

The respondents who felt poor eating was the cause of the obesity epidemic had lower body mass index scores than those who felt a lack of exercise was to blame.

Consider this correlation and your beliefs about the situation. If you think that a lack of exercise is the reason for the obesity epidemic, you may be placing too little significance on the adverse effect that excess calories of grains, sugar, and dairy products create today.

Goscienski explains the problem this way. Before man started farming, when he foraged and hunted, eating sugar occurred but only rarely. Now the average American consumes 22 teaspoons of refined sugar a day that's not counting the sugar found naturally in fruits and dairy products and since the average body doesn't need that much immediate energy, it gets transformed into fat.

But if you believe poor eating is the primary cause of obesity, you're probably far more aware of the problems that our "new" foods present. As a result, you probably eat fewer of them.

Hence, the research shows that these people have a lower body mass index.

Another study sheds light on the old catchphrase in the Lay's Potato Chips commercials: "Betcha can't eat just one."

This phenomenon of eating food not because you're hunger but simply because it tastes good is known as hedonic hyperphagia. Tobias Hoch, Ph.D. and conductor of the study, calls it "recreational eating" and cites it as a cause of the present obesity problem.

To determine the degree to which hedonic hyperphagia creates obesity, Tobias and his German colleagues fed one group of rats standard rat food; the other, potato chips.

They used magnetic resonance imaging (MRI) to see how the different diets affected the rats' brains and found that the rats' brain reacted more positively to the chips.

Later, rats were offered powdered animal chow pellets, a mixture of carbohydrates and fats, or potato chips in addition to their standard chow. Out of the three, the rats most actively pursued the potato chips even though the composition of the carb-fat mixture matched the chips.

The researchers also found eating the chips had a greater effect on the food intake, sleep, activity, and motion areas of the brain.