Healthy eating adds £1,460 to annual food bill of family of four Study co-author Professor Dariush Mozaffarian said: "This research provides the most complete picture to-date on true cost differences of healthy diets. While healthier diets did cost more, the difference was smaller than many people might have expected. Over the course of a year, £1 a day more for eating a healthy diet would increase food costs for one person by about £360 per year. This would represent a real burden for some families, and we need policies to help offset these costs. On the other hand, this price difference is very small in comparison to the economic costs of diet-related chronic diseases, which would be dramatically reduced by healthy diets. The study compared the differences in prices per serving and per 200 calories for particular types of foods, and prices per day and per 2,000 calories, a recommended average daily calorie intake for adults for overall diet patterns. Both prices per serving and per calorie were assessed because prices can vary depending on the unit of comparison. The researchers found that healthier diet patterns - for example, diets rich in fruits, vegetables, fish, and nuts - cost more than unhealthy diets which might include processed foods, meats, and refined grains. On average, a day's worth of the most healthy diet patterns cost about £1 more per day than the least healthy ones. The researchers suggested that unhealthy diets may cost less because food policies have focused on the production of "inexpensive, high volume" commodities, which has led to "a complex network of farming, storage, transportation, processing, manufacturing, and marketing capabilities that favour sales of highly processed food products for maximal industry profit." They said that supporting production of healthier foods might help increase availability and reduce the prices of more healthy diets. Fellow researcher Mayuree Rao said: "People often say that healthier foods are more expensive, and that such costs strongly limit better diet habits. But, until now, the scientific evidence for this idea has not been systematically evaluated, nor have the actual differences in cost been characterized. The study is published online in the British Medical Journal Open.