In the mid-1990s, Carlos Monteiro, a nutritional epidemiologist in Brazil, noticed something alarming: Obesity rates among children in his country were rising rapidly.
上世纪90年代中期，巴西营养流行病学家卡洛斯·蒙泰罗注意到一个令人担忧的问题：巴西儿童的肥胖率正在迅速上升。

To understand why, he and his colleagues at the University of São Paulo scrutinized data on the food buying patterns of Brazilian households to see if they had changed in recent years. The researchers found that people were purchasing less sugar, salt, cooking oils and staples like rice and beans, and more processed foods like sodas, sausages, instant noodles, packaged breads and cookies.
为了弄清其中的原因，他和圣保罗大学的同事们仔细研究了巴西家庭食品购买模式的数据，看看近年来是否发生了变化。研究人员发现，人们购买的糖、盐、食用油和大米、豆类等主食越来越少，苏打水、香肠、方便面、包装面包和饼干等加工食品越来越多。

To describe that second category of food, Dr. Monteiro said, the team introduced a new term into the scientific literature — ultraprocessed foods, or UPFs — and defined it. They would later link UPFs to weight gain in children and adults in Brazil.
蒙泰罗说，为了描述第二类食物，研究小组在科学文献中引入了一个新术语——超加工食品(UPF)，并对其进行了定义。他们随后将超加工食与巴西儿童和成人的体重增加联系起来。

Since then, scientists have found associations between UPFs and a range of health conditions, including heart disease, Type 2 diabetes, obesity, gastrointestinal diseases and depression, as well as earlier death.
从那以后，科学家们发现超加工食品与一系列健康问题之间存在联系，包括心脏病、2型糖尿病、肥胖、胃肠道疾病和抑郁症，以及过早死亡。

That’s concerning, experts say, since ultraprocessed foods have become a major part of people’s diets worldwide. They account for 67 percent of the calories consumed by children and teenagers in the United States, for example.
专家表示，由于超加工食品已成为全球人们饮食的重要组成部分，这种情况十分令人担忧。例如，它们占美国儿童和青少年摄入热量的67%。

But many questions remain. What are ultraprocessed foods, exactly? And how strong is the evidence that they’re harmful? We asked experts to answer these and other questions.
但仍存在许多问题。到底什么是超加工食品？它们有害的证据有多充分？我们请专家来回答这些问题，以及其他问题。

What are ultraprocessed foods?
什么是超加工食品?

In order to study foods based on how they were processed, Dr. Monteiro and his colleagues developed a food classification system called Nova, named after the Portuguese and Latin words for “new.” It has since been adopted by researchers across the world.
为了根据食品的加工过程来研究它们，蒙泰罗和他的同事们开发了一种名为“NOVA”的食品分类系统，这是葡萄牙语和拉丁语中“新”的意思。此后，世界各地的研究人员都采用了这种方法。

The Nova system sorts foods into four categories:
NOVA系统将食物分为四类:

• Unprocessed or minimally processed foods, like fresh or frozen fruits and vegetables, beans, lentils, meat, poultry, fish, eggs, milk, plain yogurt, rice, pasta, corn meal, flour, coffee, tea and herbs and spices.
· 未加工或最低限度加工食品，如新鲜或冷冻水果和蔬菜、豆类、扁豆、肉类、禽类、鱼、蛋、牛奶、原味酸奶、大米、意大利面、玉米粉、面粉、咖啡、茶、辛香料。

• Processed culinary ingredients, such as cooking oils, butter, sugar, honey, vinegar and salt.
· 加工烹饪原料，如食用油、黄油、糖、蜂蜜、醋和盐。

• Processed foods made by combining foods from Category 1 with the ingredients of Category 2 and preserving or modifying them with relatively simple methods like canning, bottling, fermentation and baking. This group includes freshly baked bread, most cheeses and canned vegetables, beans and fish. These foods may contain preservatives that extend shelf life.
· 加工食品是前面两类食物的结合，同时使用相对简单的方法进行防腐或改造处理，比如装罐、装瓶、发酵和烘焙。此类食品包括新鲜烘焙的面包、大多数奶酪和罐头蔬菜、豆类和鱼类。这些食品有很长的保质期。

• Ultraprocessed foods made using industrial methods and ingredients you wouldn’t typically find in grocery stores — like high-fructose corn syrup, hydrogenated oils and concentrated proteins like soy isolate. They often contain additives like flavorings, colorings or emulsifiers to make them appear more attractive and palatable. Think sodas and energy drinks, chips, candies, flavored yogurts, margarine, chicken nuggets, hot dogs, sausages, lunch meats, boxed macaroni and cheese, infant formulas and most packaged breads, plant milks, meat substitutes and breakfast cereals.
· 超加工食品使用工业方法和我们通常在生鲜杂货店里见不到的原料生产，比如高果糖玉米糖浆、氢化油和大豆分离蛋白之类的浓缩蛋白质。它们通常包括调味剂、染色剂或乳化剂之类的添加剂，让它们的外观和味道更具吸引力。比如汽水和能量饮品、薯片、糖果、加味酸奶、人造黄油、炸鸡块、热狗、香肠、午餐肉、盒装奶酪通心粉、婴儿配方奶和大多数包装面包、植物奶、素肉和早餐谷物。

“If you look at the ingredient list and you see things that you wouldn’t use in home cooking, then that’s probably an ultraprocessed food,” said Brenda Davy, a nutrition professor at Virginia Tech.
“看一下成分表，如果能看到一些在家里做饭不会用到的东西，那可能就是超加工食品了，”弗吉尼亚理工营养学教授布伦达·达维说。

The Nova system notably doesn’t classify foods based on nutrients like fat, fiber, vitamins or minerals. It’s “agnostic to nutrition,” said Maya Vadiveloo, an associate professor of nutrition at the University of Rhode Island.
值得注意的是，NOVA系统并未根据脂肪、纤维、维生素或矿物质这样的营养成分来进行分类。它是“无视营养的”，罗德岛大学营养学副教授玛雅·瓦迪威卢说。

That has led to debate among nutrition experts about whether it’s useful for describing the healthfulness of a food, partly since many UPFs — like whole grain breads, flavored yogurts and infant formulas — can provide valuable nutrients, Dr. Vadiveloo said.
营养专家们因此对该系统是否能用于描述一种食品的健康程度展开了辩论，瓦迪威卢说，这一定程度上是因为，许多超加工食品——比如全麦面包、加味酸奶和婴儿配方奶——是可以提供有价值的营养素的。

Are ultraprocessed foods harmful?
超加工食品是否有害？

Most research linking UPFs to poor health is based on observational studies, in which researchers ask people about their diets and then track their health over many years. In a large review of studies that was published in 2024, scientists reported that consuming UPFs was associated with 32 health problems, with the most convincing evidence for heart disease-related deaths, Type 2 diabetes and common mental health issues like anxiety and depression.
将超加工食品和不健康联系起来的研究大多是观察性的，研究人员在几年时间里询问一些人的饮食，然后跟踪他们的健康状况。在2024年发表的一项大型研究回顾中，科学家称摄入超加工食品与32种健康问题有关联，其中有关心脏病相关死亡、2型糖尿病和焦虑、抑郁等常见精神健康问题的证据最具说服力。

Such studies are valuable, because they can look at large groups of people — the 2024 review included results from nearly 10 million — over the many years it can take for chronic health conditions to develop, said Josiemer Mattei, an associate professor of nutrition at the Harvard T.H. Chan School of Public Health. She added that the consistency of the link between UPFs and health issues increased her confidence that there was a real problem with the foods.
这类研究是有价值的，因为它们可以覆盖大片人群——2024年的回顾包括了对将近1000万人的研究结果——时间跨度长达数年，因而可以观察到慢性健康问题的发展，哈佛陈曾熙公共卫生学院营养学副教授约西梅尔·马泰说。她还表示，超加工食品与健康问题的关联表现出了连贯性，这让她愈发相信，这类食品的确存在问题。

But the observational studies also have limitations, said Lauren O’Connor, a nutrition scientist and epidemiologist who formerly worked at the Department of Agriculture and the National Institutes of Health. It’s true that there is a correlation between these foods and chronic diseases, she said, but that doesn’t mean that UPFs directly cause poor health.
但是曾供职于农业部和国立卫生研究院的营养科学家、流行病学家劳伦·奥康纳说，观察性研究有其局限。她说这类食品与慢性病的确存在关联，但这并不等于超加工食品会直接导致健康问题。

Dr. O’Connor questioned whether it’s helpful to group such “starkly different” foods — like Twinkies and breakfast cereals — into one category. Certain types of ultraprocessed foods, like sodas and processed meats, are more clearly harmful than others. UPFs like flavored yogurts and whole grain breads, on the other hand, have been associated with a reduced risk of developing Type 2 diabetes.
奥康纳认为，将如此“截然不同的”食物——比如Twinkie蛋糕和早餐谷物——归为一类可能是没什么好处的。某些超加工食品，比如汽水和加工肉类，害处相对更大。而像加味酸奶和全麦面包这样的超加工食品，却与降低2型糖尿病风险有关。

Clinical trials are needed to test if UPFs directly cause health problems, Dr. O’Connor said. Only one such study, which was small and had some limitations, has been done, she said.
奥康纳说，要明确超加工食品是否直接导致健康问题，需要进行临床试验。她说这样的研究目前只有一项，而且规模很小，存在一些缺陷。

In that study, published in 2019, 20 adults with a range of body sizes lived in a research hospital at the National Institutes of Health for four weeks. For two weeks, they ate mainly unprocessed or minimally processed foods, and for another two weeks, they ate mainly UPFs. The diets had similar amounts of calories and nutrients, and the participants could eat as much as they wanted at each meal.
在这项2019年发表的研究中，20名体型各异的成年人在国立卫生研究院的一家研究医院住了四周。其中有两周主要吃未经加工或只有少量加工的食物，另外两周主要吃超加工食品。两种饮食的热量和营养差不多，受试者可以想吃多少就吃多少。

During their two weeks on the ultraprocessed diet, participants gained an average of two pounds and consumed about 500 calories more per day than they did on the unprocessed diet. During their time on the unprocessed diet, they lost about two pounds.
在食用超加工食品的两周里，受试者的体重平均增加了近一公斤，每天摄入的热量比食用未加工食品的那两周多了约500卡路里。在食用未加工食品期间，他们的体重减了约一公斤。

That finding might help explain the link between UPFs, obesity and other metabolic conditions, said Kevin Hall, a nutrition and metabolism researcher at the National Institutes of Health, who led the trial. But the study needs to be replicated, which Dr. Hall is in the process of doing now.
主持该试验的卫生研究院营养和代谢研究人员凯文·霍尔说，这些发现可能有助于解释超加工食品与肥胖和其它代谢问题的关联。但是该研究结果需要进行复现，霍尔正在进行这项工作。

Why might UPFs be harmful?
为什么超加工食品可能有害？

There are many “strong opinions” about why ultraprocessed foods are unhealthy, Dr. Hall said. “But there’s actually not a lot of rigorous science” on what those mechanisms are, he added.
霍尔说，围绕超加工食品为什么不健康有许多“激烈的观点”。但是具体是怎样的机制，“其实没有多少严谨的科学基础，”他说。

Because UPFs are often cheap, convenient and accessible, they’re probably displacing healthier foods from our diets, Dr. Hall said.
由于超加工食品往往廉价、方便、易获取，它们可能正在取代我们的饮食中相对健康的食物，霍尔说。

But he and other scientists think that the foods could be having more direct effects on health. They can be easy to overeat — maybe because they contain hard-to-resist combinations of carbohydrates, sugars, fats and salt, are high-calorie and easy to chew. It’s also possible that resulting blood sugar spikes may damage arteries or ramp up inflammation, or that certain food additives or chemicals may interfere with hormones, cause a “leaky” intestine or disrupt the gut microbiome.
但是包括他在内的一些科学家认为，这类食品可能会给我们的健康造成更直接的影响。这种食物很容易过量食用——可能是因为其中包含令人难以抗拒的碳水化合物、食糖、脂肪和盐的组合，热量高且易于咀嚼。由此产生的血糖急升可能会伤害动脉或加剧炎症，或者某种食品添加剂或化学品可能干扰荷尔蒙水平，导致肠道“泄漏”或扰乱肠道菌群。

Researchers, including Dr. Hall and Dr. Davy, are beginning to conduct small clinical trials that will test some of these theories. Such studies may help identify the most harmful UPFs and even suggest how they may be made healthier, Dr. Hall said.
包括霍尔和达维在内的研究人员正在展开小型临床试验，以验证这些假说。这类研究可能有助于识别最有害的超加工食品，甚至从中了解可以如何使它们变得更健康，霍尔说。

But most researchers think there are various ways the foods are causing harm. “Rarely in nutrition is there a single factor that fully explains the relationship between foods and some health outcome,” Dr. Vadiveloo said.
不过，大多数研究人员认为，食物造成伤害的方式是多种多样的。“在营养学中，食物和某些健康后果之间的关系，很少能只用某个单一的因素解释，”瓦迪威卢说。

What should we do about ultraprocessed foods?
我们该如何对待超加工食品？

In 2014, Dr. Monteiro helped write new dietary guidelines for Brazil that advised people to avoid ultraprocessed foods.
2014年，蒙泰罗参与撰写的巴西新饮食指引建议避免食用超加工食品。

Other countries like Mexico, Israel and Canada have also explicitly recommended avoiding or limiting UPFs or “highly processed foods.” The U.S. dietary guidelines contain no such advice, but an advisory committee is currently looking into the evidence on how UPFs may affect weight gain, which could influence the 2025 guidelines.
另外像墨西哥、以色列和加拿大等国家也明确建议避免或限制对超加工食品或“精加工食品”的摄入。美国饮食指引没有提出类似建议，不过一个顾问委员会目前正在研判有关超加工食品导致体重增加的证据，可能影响2025年版的指引。

It’s difficult to know what to do about UPFs in the United States, where so much food is already ultraprocessed and people with lower incomes can be especially dependent on them, Dr. Hall said.
超加工食品在美国是个很棘手的问题，因为已经有太多食品是经过超加工的，低收入人群可能尤其依赖这类食品，霍尔说。

“At the end of the day, they are an important source of food, and food is food,” Dr. Mattei added. “We really cannot vilify them,” she said.
“说到底这些都是重要的食物来源，食物就是食物，”马泰也说。“我们不能去贬低它们。”

While research continues, expert opinions differ on how people should approach UPFs. Dr. Monteiro said that the safest course is to avoid them altogether — to swap flavored yogurt for plain yogurt with fruit, for example, or to buy a fresh loaf from a local bakery instead of packaged bread, if you can afford to do so.
在各项研究仍在进行的同时，专家对应该如何对待超加工食品存在不同意见。蒙泰罗说最稳妥的办法就是完全不吃——比如用原味酸奶和水果取代加味酸奶，或到本地面包房购买新鲜面包，不买包装面包，如果经济情况允许的话。

Dr. Vadiveloo suggested a more moderate strategy, focusing on limiting UPFs that don’t provide valuable nutrients, like soda and cookies. She also recommended eating more fruits, vegetables, whole grains (ultraprocessed or not), legumes, nuts and seeds.
瓦迪威卢提出了相对中庸的策略，专注于限制不能带来有价值的营养素的超加工食品，比如汽水和饼干。她还建议多吃水果、蔬菜、全麦（无论是否经过超加工）、豆类、坚果和种子类食物。

Cook at home as much as you can, using minimally processed foods, Dr. Davy said. “We can’t really say a whole lot beyond that at this point.”
尽可能在家做饭，尽量少用经过加工的食物，达维说。“除此之外就没什么可说的了。”
(本新闻网址：https://www.geilien.cn/news/2024/nyultraprocessed.html)

本文最初发表于2024年5月6日。

Alice Callahen是时报负责报道营养和健康的记者。她在加州大学戴维斯获得了营养学博士学位。

翻译：晋其角、Duran