Centre for Science, Athabasca University, Athabasca, Alberta, Canada.
Nutrition. 2011 May;27(5):505-8. doi: 10.1016/j.nut.2010.09.005. Epub 2010 Nov 13.
Energy-dense foods are relatively cheap sources of energy but typically have a low nutrient density. People with a low income may therefore select a relatively less healthy diet. The high energy density of such diets helps explain the association between obesity and low socioeconomic status. Most studies have been carried out in highly developed countries. We have extended this research to South Africa. Some foods, such as oats, beans, carrots, and apples, are moderately priced sources of energy and are healthy (i.e., they have a low energy density and are nutrient dense). However, such foods are likely to be less desired than many other foods, such as candy, cookies, jam, and chocolate, that have a similar cost (in terms of food energy) but are less healthy. We compared the cost of a typical South African diet with a healthier one. On average, the healthier diet costs 69% more, but this estimate is greatly affected by food choices. For a family whose household income is exceeded by one-third of the population, this increased expenditure represents about 30% of total household income. This could be decreased to about 10% to 15% if a healthy diet is carefully designed. Overall, a healthy diet is unaffordable for most South Africans. This shows the importance of not only educating people in developing countries to the importance of a healthy diet but also explaining how to make such a diet affordable. A more effective strategy is government intervention that manipulates food prices.
高能量密度的食物相对来说是较为廉价的能量来源,但通常其营养价值较低。因此,低收入人群可能会选择相对不太健康的饮食。这种高能量密度的饮食有助于解释肥胖症与社会经济地位低下之间的关联。大多数此类研究都在高度发达的国家进行。我们已经将这一研究扩展到南非。一些食物,如燕麦、豆类、胡萝卜和苹果,其价格适中且是健康的(即能量密度低而营养价值高)。然而,与其他许多食品相比,这些食物的需求量可能较低,如糖果、饼干、果酱和巧克力,这些食品的成本(以食物能量来衡量)相当,但健康程度较低。我们比较了典型的南非饮食与更健康的饮食的成本。平均而言,更健康的饮食成本高出 69%,但这一估计受到食物选择的极大影响。对于一个家庭来说,如果其家庭收入超过人口的三分之一,那么这一额外支出占家庭总收入的 30%左右。如果精心设计健康饮食,这一支出可减少到 10%到 15%左右。总体而言,健康饮食对大多数南非人来说是难以负担的。这表明,不仅要教育发展中国家的人们重视健康饮食,还要解释如何使这种饮食负担得起,这一点非常重要。一个更有效的策略是政府干预,通过操纵食品价格来实现。