雅思阅读 127: The Over-Processed Diet（过度加工的饮食）

改编从 Nature / NIH / UK Biobank（2025年）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://www.nhlbi.nih.gov/news/2025/spotlight-upfs-nih-explores-link-between-ultra-processed-foods-and-heart-disease

Reading Passage

A. Walk through any supermarket in Europe, North America or urban Latin America and the vast majority of items on sale fall into a category that nutrition scientists call "ultra-processed". These are not simply foods that have been cooked, tinned or frozen; they are formulations of industrial ingredients — refined oils, sugars, modified starches, hydrogenated fats, emulsifiers, artificial flavours and colours — assembled into products designed to be hyper-palatable, shelf-stable and inexpensive. Breakfast cereals, flavoured yoghurts, mass-produced bread, savoury snacks, sugary drinks, reconstituted meat products and instant noodles all fall under this umbrella. The NOVA classification, which divides foods into four levels of processing from unprocessed to ultra-processed, has become one of the most influential frameworks in contemporary nutrition research, because population studies over the past decade have tied high ultra-processed food intake to an alarming list of adverse outcomes: obesity, type-2 diabetes, cardiovascular disease, certain cancers and, more recently, cognitive decline and depression.

B. The evidence from large cohort studies has grown harder to dismiss. A 2025 analysis using data from the UK Biobank, tracking 172,225 adults, found that participants consuming the largest share of ultra-processed foods showed both accelerated biological-age markers and higher all-cause mortality. A separate National Institutes of Health study, published the same year, reported that the highest UPF consumers faced a 17 per cent greater risk of cardiovascular disease, a 23 per cent greater risk of coronary heart disease and a 9 per cent greater risk of stroke compared with the lowest consumers. Review papers have linked UPF intake to elevated risk of colorectal and breast cancers, as well as to neurodegeneration and mood disorders. In high-income countries, ultra-processed foods now supply between half and three-quarters of all dietary energy consumed, depending on the country — a share that has risen steadily since the 1990s and shows no sign of reversing. What makes these findings noteworthy is not the association alone — observational nutrition studies are plentiful — but their consistency across countries, age groups and dietary cultures, and the fact that the associations persist even after researchers control for obvious confounders such as education, smoking and total physical activity.

C. Why should a category label, rather than a specific nutrient, track so reliably with disease? Several mechanisms are now under investigation. The first is simply nutritional displacement: ultra-processed foods tend to be dense in calories but sparse in fibre, vitamins and the phytochemicals found in whole plants, so a diet built around them crowds out foods that genuinely protect health. Because UPFs are also cheaper per calorie than fresh produce, the burden falls disproportionately on lower-income households, for whom a bag of crisps and a sugary drink is both more affordable and more accessible than a cooked vegetable meal. The second is behavioural: their soft, uniform texture and intense flavour encourage rapid eating, before gut hormones signalling fullness have time to reach the brain, leading people to overconsume without realising it. The third involves the ingredients themselves — emulsifiers such as carboxymethylcellulose and polysorbates have been shown in animal studies to alter the gut microbiota in ways that promote low-grade inflammation and insulin resistance. Processing contaminants formed at high temperatures, including acrylamide and advanced glycation end-products, add a further layer of exposure that unprocessed diets avoid. A fourth mechanism, still under investigation, involves the food environment itself: ultra-processed products are engineered to bypass the brain's satiety circuitry, combining textures and flavours that are difficult to replicate at home, and are marketed heavily through digital channels that make them disproportionately visible to children and adolescents.

D. The causal question was addressed most directly by a controlled feeding trial reported in Nature in August 2025. Researchers matched ultra-processed and unprocessed diets for calories, sugar, salt and macronutrients, then assigned overweight adults to eat either diet for two weeks before switching. Even when the meals were nutritionally equivalent on paper, the participants on the ultra-processed regimen ate roughly 500 calories more per day and gained weight, while those on the unprocessed regimen lost weight. The finding implied that processing itself — not just sugar or fat content — drives overeating, probably through the texture-and-speed mechanism. But the study also provoked a counter-debate. Critics pointed out that the NOVA label laces together products as different as a vegan protein shake and a sugary children's cereal, and that some "ultra-processed" plant-based foods may actually help people reduce meat consumption. A 2026 review in BMJ Nutrition concluded that not all ultra-processed foods are equally harmful, and that classifying them as a single exposure may obscure meaningful differences.

E. The public-health response is now taking shape, though unevenly. Countries including Brazil, Uruguay and Israel have revised national dietary guidelines to urge citizens to prefer unprocessed or minimally processed foods, regardless of the nutrient profile of the processed alternatives. Industry, for its part, has responded by reformulating: removing artificial colours, reducing added sugar and salt, adding fibre — while keeping the same industrial structure. Whether such reformulation actually reduces disease risk, or merely launders the same products under a healthier label, is an open empirical question. The deeper policy levers — taxation, marketing restrictions on children, public procurement of unprocessed meals in schools — remain politically contested. A sugar-style tax on all ultra-processed foods, though advocated by some public-health campaigners, has so far proved politically unpopular and administratively complicated, precisely because the NOVA category lumps together products of very different nutritional quality. What is no longer seriously disputed is that a diet dominated by ultra-processed food is associated with measurable harm, and that the most robust intervention remains the oldest one: cook meals from fresh ingredients, at home, as often as circumstances allow. Whether that message will reach consumers as forcefully as the advertising campaigns for the products themselves is, of course, an entirely different question.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. What ultra-processed foods are ii. The large-cohort evidence linking them to disease iii. Why a category label predicts harm: proposed mechanisms iv. The controlled trial — and the counter-debate v. The public-health response and its limits vi. The history of the NOVA classification vii. How to bake an unprocessed cake

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. In the UK Biobank study, what did high UPF intake correlate with? A. Lower blood pressure. B. Accelerated biological ageing and higher mortality. C. Better cognitive performance. D. Improved gut microbiota.

6. According to the NIH study, the highest UPF consumers had what increase in coronary heart disease risk? A. 9 per cent. B. 17 per cent. C. 23 per cent. D. 50 per cent.

7. What did the 2025 Nature controlled feeding trial find? A. Ultra-processed and unprocessed diets produced identical outcomes. B. Participants on ultra-processed diets ate about 500 more calories per day. C. Unprocessed foods tasted worse. D. Ultra-processed foods helped people lose weight.

8. What is the main criticism of the NOVA classification? A. It ignores the role of genetics. B. It groups very different products together, obscuring meaningful differences. C. It was invented by the food industry. D. It only applies to European diets.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. The NOVA system divides foods into four levels of processing.
10. Ultra-processed foods are typically high in fibre and phytochemicals.
11. Emulsifiers have been shown in animal studies to alter gut microbiota.
12. Brazil has changed its national dietary guidelines to prefer unprocessed foods.
13. The food industry has stopped producing ultra-processed products entirely.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

The mechanisms linking UPFs to harm include nutritional (14) __________, rapid eating that overrides satiety signals, and additives that disrupt the gut (15) __________.

答案与解析

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