Eating ourselves to death
By BMJ Group
Ready-to-eat meals and heat-and-serve snacks have become increasingly common in diets around the world over the past few decades. As people eat more of these heavily processed products, researchers have been trying to work out whether there is a safe amount to consume and where the risks to long-term health might begin.A large pooled analysis, published in the open access
journal Family Medicine and Community Health, found that higher
consumption was linked to greater risks of several chronic diseases and death
from any cause. Across 51 studies involving 8,819,894 adults, the risks
generally rose with the amount eaten.
Higher risks with every extra 100 grams
Ultra-processed foods undergo extensive industrial
processing and typically contain a range of additives. They also tend to pack
in calories, sugar, and salt while providing relatively little fiber, protein,
vitamins, or minerals. But understanding their relationship with health
requires more than knowing what is in them. The researchers wanted to examine
how the quantity people consumed related to their chances of developing disease
over time.
They approached that question in two ways, comparing people
with higher and lower intakes and examining how risk changed with each
additional amount consumed. For cardiovascular events, higher consumption was
associated with a 24% greater risk. Looking at daily amounts, every extra 100
grams, about 3.5 ounces, was linked to a 14% increase in risk. The
cardiovascular outcomes included heart attacks, strokes, transient ischemic
attacks, sometimes called “mini strokes,” coronary artery disease, and cardiovascular
death.
Those percentages describe relative differences between
risks. They do not mean that 24% or 14% of the people eating these foods
experienced a cardiovascular event.
For cancer, the analysis linked higher consumption to a 12%
greater risk, while each additional 100 grams per day was associated with a 4%
increase. The cancer outcomes examined included deaths from cancer. Death from
any cause was also more likely among people with higher intakes, with an 18%
greater risk overall and a 3% increase associated with each extra 100 grams
consumed daily.
The findings also connected ultra-processed food intake with
problems involving blood sugar, blood pressure, and body weight. Higher
consumption was associated with a 24% greater risk of metabolic syndrome or
diabetes. Metabolic syndrome describes a group of conditions, including
elevated blood pressure and blood sugar, that together increase the risk of
heart disease and diabetes. The analysis also found an 11% greater risk of high
blood pressure and a 23% greater risk of overweight or obesity among people
with higher intakes.
For metabolic syndrome or diabetes, each additional 100
grams eaten daily was associated with a 2% increase in risk. The researchers
also examined consumption measured by weight or energy intake, finding a 16%
greater risk for every 10% increase in ultra-processed food intake on those
measures.
The associations extended to digestive and mental health,
with higher consumption linked to a 31% greater risk of digestive diseases and
a 27% greater risk of depression or anxiety. Several of the chronic conditions
examined can occur together in the same person, known as multimorbidity, which
informed the researchers’ discussion of prevention and care.
“Given that UPF-related chronic diseases often cluster as
multimorbidity, reducing consumption of UPFs and replacing them with minimally
processed alternatives may be relevant for chronic disease prevention and
primary care management,” they conclude.
What processing may do to the gut
The analysis could not establish that ultra-processed foods
caused these illnesses, although the researchers discussed several biological
explanations that might help account for the links. Laboratory studies suggest
that extensive processing can alter the physical structure of food in ways that
may affect the gut microbiome, the community of microorganisms living in the
digestive tract. These changes may also promote inflammation and insulin
resistance, which makes it harder for the body to respond to the hormone that
regulates blood sugar.
The researchers also pointed to emerging evidence that
multiple additives may act together to produce a “cocktail effect” on health.
Other potentially relevant substances form during processing itself.
Acrylamide, a contaminant that can develop in heat-treated processed foods, and
acrolein, generated when fats are heated, have both been associated with a
higher incidence of cardiovascular disease.
Diet and lifestyle are hard to separate
To establish how these possibilities relate to people’s
long-term health, researchers must contend with the difficulty of measuring
diets over many years. The studies included in this analysis followed
participants for two to 32 years and assessed their diets through food
frequency questionnaires, reports of what they had eaten in the previous 24
hours, or dietary histories. All, therefore, depended on people’s accounts of
their eating habits. The researchers converted daily intake in grams into
50-gram servings, about 1.8 ounces, to help compare consumption across studies.
The studies came from the Americas, Europe, Asia, and
Oceania and were identified through searches covering research published
through the end of April 2026. Average participant ages ranged from 23 to 77,
and people younger than 18 were excluded.
Even with years of follow-up, it is difficult to fully
separate food choices from the other habits that accompany them. The
researchers acknowledged that broader lifestyle and behavioral patterns could
influence the risks of chronic disease and death, and that the included studies
could not fully account for those influences.
Reference: “Ultra-processed food consumption and risk of
multiple chronic diseases among 8,819,894 adults from 51 prospective cohorts: a
dose-response meta-analysis” by Xiao Liu, Shengwei Luo, Yunting Zeng, Nanqin
Peng, Xinyi Chen, Jianan Tian, Ling Lin, Shan Zeng, Yewei Xie, Zexuan Wang,
Jiaxue Xu, Lin Li, Deju Zhang, Wenli Gu, Xiang Gu, Jun Zhang, Menglu Liu, Yujie
Zhao, Lihan Zhu, Mir Wajid Majeed, Zhiwei Yan, Wenting Wang and Peng Yu, 22
September 2026, Family Medicine and Community Health.
DOI:
10.1136/fmch-2026-003925
Funding: Natural Science Foundation of China; Natural
Science Foundation in Jiangxi Province; Jiangxi Province Thousands of Plan
Meeting: 2025 Annual Meeting of American College of
Cardiology Asia
