Given the question: Write a multi-choice question for the following article, with the given choices and answer: Article: Eating foods high in trans-fats(fats present in artificial form in industrially-produced cakes and fast food...) and saturated fats increases the risk of depression, according to a Spanish study, confirming previous studies that linked "junk food" with the disease. Researchers also showed that some products, such as olive oil, can fight against the risk of mental illness. Authors of the wide-reaching study, from the universities of Navarra and Las Palmas, followed and analyzed the diet and lifestyle of over l2,000 volunteers over six years. When the study began, none of the participants had been diagnosed with depression; by the end, 657 of them were new sufferers. "Participants with an increased consumption of trans-fats presented up to a 48 percent increase in the risk of depression when they were compared to participants who did not consume these fats," the head study author said. "The more trans-fats were consumed, the greater harmful effect they produced in the volunteers." The research team found, at the same time, that after assessing the effect of polyunsaturated fats made up of larger amounts of fish and vegetable oils and olive oil, these products are associated with a lower risk of suffering depression. The report, published in the online journal PLOS ONE, noted the research was performed on a European population that enjoys a relatively low intake of trans-fats--making up only 0.4 percent of the total energy taken in by the volunteers. "Despite this, we observed an increase in the risk of suffering depression of nearly 50 percent," said researcher Miguel Martinez. "On this basis we think it of great importance to take this effect into account in countries like the United States, where the percentage of energy _ from these fats is around 2.5 percent." The report pointed out that the current number of depression sufferers in the world is around l50 million people, and has increased in recent years. This rise is attributable, according to the authors, "to great changes in the sources of fats... Options: A they have less time for exercise B they eat more nuts, vegetable oils and fish C the sources of fats in their diets have changed D less meat, butter, and cakes are included in their diets Answer: C the sources of fats in their diets have changed Question:
The answer is:
More and more Westerners are suffering depression because _ .