Every five years, the government tries to tell Americans what to put in their bellies. Eat more vegetables. Dial back the fats. It’s all based on the best available science for leading a healthy life. But the best available science also has a lot to say about what those food choices do to the environment, and some researchers are annoyed that new dietary recommendations of the USDA (United States Department of Agriculture) released yesterday seem to utterly ignore that fact.

        Broadly, the 2016-2020 dietary recommendations aim for balance: More vegetables, leaner meats and far less sugar.

        But Americans consume more calories per capita than almost any other country in the world. So the things Americans eat have a huge impact on climate change. Soil tilling releases carbon dioxide, and delivery vehicles emit exhaust. The government’s dietary guidelines could have done a lot to lower that climate cost. Not just because of their position of authority: The guidelines drive billions of dollars of food production through federal programs like school lunches and nutrition assistance for the needy.

        On its own, plant and animal agriculture contributes 9 percent of all the country’s greenhouse gas emissions. That’s not counting the fuel burned in transportation, processing, refrigeration, and other waypoints between farm and belly. Red meats are among the biggest and most notorious emitters, but trucking a salad from California to Minnesota in January also carries a significant burden. And greenhouse gas emissions aren’t the whole story. Food production is the largest user of fresh water, largest contributor to the loss of biodiversity, and a major contributor to using up natural resources.

        All of these points and more showed up in the Dietary Guidelines Advisory Committee’s scientific report, released last February. Miriam Nelson chaired the subcommittee in charge of sustainability for the report, and is disappointed that eating less meat and buying local food aren’t in the final product. “Especially if you consider that eating less meat, especially red and processed, has health benefits,” she says.

        So what happened? The official response is that sustainability falls too far outside the guidelines’ official scope, which is to provide “nutritional and dietary information.”

        Possibly the agencies in charge of drafting the decisions are too close to the industries they are supposed to regulate. On one hand, the USDA is compiling dietary advice. On the other, their clients are US agriculture companies.

        The line about keeping the guidelines’ scope to nutrition and diet doesn’t ring quite right with researchers. David Wallinga, for example, says “In previous guidelines, they’ve always been concerned with things like food security—which is presumably the mission of the USDA. You absolutely need to be worried about climate impacts and future sustainability if you want secure food in the future.”

解析：D。根据题干中的some researchers和the USDA’s 2016-2020 Dietary Guidelines可定位至原文首段最后一句和第二段。首段最后一句提到，最先进的科学还有很多是关于这些食物选择对环境的影响，而且令一些研究人员感到恼火的是，美国农业部昨天发布的新版膳食建议似乎完全忽视了这一事实。随后第二段列出了膳食指南的内容。由此可知，研究人员恼火的原因是美国农业部的膳食建议忽视了关于食物选择的建议对环境的影响，D项与此表述一致，其中takes no notice对应原文首段结尾处的ignore，the potential impact on the environment对应原文中的what those food choices do to the environment，故正确答案为D。

错项排除：文章第一段明确指出，研究人员恼火的原因是膳食指南忽略了食物对环境的影响这一问题，并没有提到red meat and processed food，A项利用ignores以及第五段末尾出现的red and processed作干扰进行细节拼凑，故排除A项。原文第五段指出，少吃肉和购买本地食品都没有出现在最终发布的膳食指南中，可见指南并没有强调这两点，故B项错误。C项利用原文首段出现的based on the best available science作干扰，但这里表示的是政府的很多建议都是基于目前最先进的科学关于健康生活的理念，与medical science无关，故排除C项。