Eating a Mediterranean diet rich in fish, olive oil, legumes, fruit and vegetables may strengthen the heart but the cost strains the wallet and may deter healthy eating, according to Spanish researchers. A study by the Department of Preventive Medicine and Public Health at the University of Navarra looked at the costs of Mediterranean and Western diets in more than 11,000 Spanish university graduates with a similar level of income. All of them were taking part in a long term study launched in 1999 to assess ties between diet, food costs and obesity. The analysis, published in the Journal of Epidemiology and Community Health, revealed that the more closely these people adhered to a healthy Mediterranean diet, the more money they spent each day on food. In contrast, the more closely they followed a “Western” diet - high in saturated fat, sugar, and red meat - the less money they shelled out each day on food. Researcher Maira Bes-Rastrollo said this study showed that a healthy Mediterranean dietary pattern is more expensive to follow than a Western dietary pattern. “I am sure that the same study conducted in the United States would find the same results or even higher differences in costs between dietary patterns,” she said in a statement. This “economic barrier” should be considered when counseling populations about following a healthy diet “because cost may be a prohibitive factor,” she added. The researchers also found that 31 percent of study subjects gained weight during the study - just over half a kilo, or 1.1 pounds, every year. After adjusting for factors likely to influence the results, people who spent the most on food were 20 percent more likely to gain weight, regardless of which dietary pattern they favored. Those with higher food bills tended to be older, were more likely to have quit smoking, tended to drink more calorie-laden fruit juice and soft drinks and generally weighed more to begin with - suggesting that they were more prone to weight gain due to lifestyle or genetic factors, the researchers said.