Reducing the price of healthy foods could land more whole grains, carrots and bananas in shopping carts, even months after the discounts are removed, according to a new study.

    As rates of obesity continue to rise in much of the developed world, so does the urgency to improve people's food choices. Ni Mhurchu and her team conducted a six-month trial across eight New Zealand supermarkets to determine the effects of two strategies: price discounts and nutrition education.

    A total of 1,104 shoppers were randomized to receive a price discount on healthy foods, tailored nutrition education, a combination of the two or no intervention. Healthy foods, as recognized by New Zealand's Heart Foundation, were 12.5 percent cheaper for those randomized to receive discounts. Participants assigned to nutrition education received monthly packages of food-group-specific information, which were tailored to their shopping history. Handheld barcode scanners recorded all supermarket purchases.

    According to a report in the American Journal of Clinical Nutrition, after six months of intervention, participants receiving price discounts bought approximately 1.7 more pounds （790 grams） of healthy food per week compared with those not randomized to pay the lower prices.

    This was an 11 percent increase from purchases made prior to the study and included just over a pound （480 grams） more fruits and vegetables per week, or about six servings. The total difference dropped to around 0.8 pounds （380 grams）, but remained significant, six months after the study was over. No consistent differences were found between the groups in the amounts of purchased saturated fat or other nutrients.

    The fact that nutrition education was unsuccessful in improving food choices initially surprised Ni Mhurchu, especially since previous research had shown positive effects. Most of those studies, however, used self-report rather than the more objective supermarket sales data. Still, she said, her study participants were generally more informed and interested in healthy eating than average individuals, which could have masked education's true impact.

    一項新的研究顯示，健康食品降價行為會促使消費者購買更多粗糧、胡蘿卜以及香蕉等產品。該研究表明，這種趨勢甚至持續到打折期過后數月。

    隨著肥胖問題在許多發達國家愈演愈烈，改善人們對于食物的選擇也成為迫切需要完成的課題。

    Ni Mhurchu 及其團隊在新西蘭的八家超市中進行了長達六個月的追蹤實驗，以此評價兩種不同策略的效應：降價出售與營養教育。

    共有1104名消費者參與此項調查。他們被隨機分配為四組：健康食品降價；接受特定的營養教育；兩者兼而有之；以及無干預行為。在該實驗中，健康食品（根據新西蘭心臟組織的定義標準）的折扣價為原價的77.5%.而參加營養教育的消費者，根據各自不同的購物歷史，每月都會收到詳細的分類食物資料。期間所有超市的消費信息都經條形碼掃描記錄。

    《美國臨床營養學雜志》的一份報告中稱，經過六個月的干預實驗，與其他組相比，接受降價的消費者購買的健康食品平均每周多出約1.7磅（即790克）.這比研究之前增加了11%,其中包括水果和蔬菜的周購買量提高了一磅（即480克）,大約是六人份的餐量。

    此項研究結束6個月后，該數據雖然降低至0.8磅（約380克）,但仍然有著深遠的意義。各組在飽和脂肪等其他營養成分的消費中沒有出現相應的不同。

    由于此前有研究曾經證實營養教育在人們改善食物選擇方面有著積極作用，Ni Mhurchu 完全沒有料到營養教育策略在該實驗中竟然沒有成功。然而，之前的大部分研究都是采用自身評定的方式，而超市的銷售數據則顯得更為客觀。Ni Mhurchu 認為，此次實驗參與者比一般人更加了解和關注健康飲食，也許這一點恰恰隱藏著教育的真正意義。