• Most ultraprocessed foods (UPFs) are characterized by poor nutritional quality, contributing to excessive calories, and are typically high in saturated fats, added sugars and sodium (salt), the combination of which is often abbreviated as HFSS, which contribute to adverse cardiometabolic health outcomes, including heart attack, stroke, obesity, inflammation, Type 2 diabetes and vascular complications.
• Observational studies have found links between eating higher amounts of UPFs and an increased risk of cardiovascular disease, chronic illness and mortality.
• Emerging evidence also suggests certain additives and industrial processing techniques may have negative health effects.
• However, not all UPFs are junk foods or have poor nutritional quality; some UPFs have better nutritional value and can be part of an overall healthy dietary pattern.
• Experts recommend multilevel strategies, including more research to uncover how UPFs specifically impact the body, refining dietary guidance to discourage excessive consumption of nutrient-poor UPFs, clarifying the impact of the limited number of UPFs with more favorable nutrition profiles, more research on the health impacts of food additives and evidence-based policies to evaluate and regulate food additives.

Ultraprocessed foods or UPFs are a growing concern due to their widespread consumption and impact on potential health risks. Most UPFs, particularly those commonly seen in U.S. dietary patterns, are high in saturated fat, added sugars and sodium (salt), the combination of which is often abbreviated as HFSS, and contribute to excess calories. These include sugar-sweetened drinks, ultraprocessed meats, refined grains, candy and commercial baked goods, among others. A limited number of ultraprocessed foods, such as certain commercial whole grains, low-fat-low-sugar dairy, and some plant-based items, have positive nutritional value and, therefore, can be part of an overall healthy dietary pattern. This overlap is confusing for health care professionals and the public.

A new Science Advisory from the American Heart Association, "Ultraprocessed Foods and Their Association with Cardiometabolic Health: Evidence, Gaps and Opportunities," summarizes current knowledge about UPFs and their impact on cardiometabolic health, and outlines opportunities for research, policy and regulatory reform to improve dietary intake and overall health. The manuscript published on August 8 in Circulation, the flagship journal of the American Heart Association.

"The relationship between UPFs and health is complex and multifaceted," said Maya K. Vadiveloo, Ph.D., R.D., FAHA, volunteer chair of the writing group for this Science Advisory. "We know that eating foods with too much saturated fat, added sugars and salt is unhealthy. What we don't know is if certain ingredients or processing techniques make a food unhealthy above and beyond their poor nutritional composition. And if certain additives and processing steps used to make healthier food like commercial whole grain breads have any health impact."

The rapid rise in UPF consumption since the 1990s disrupted traditional dietary patterns, potentially contributing to adverse health effects. It is estimated that 70% of grocery store products in the U.S. contain at least one ultraprocessed ingredient. As detailed in a CDC report published on August 7, 55% of calories consumed by people ages 1 and older in the U.S. were UPFs. Among youth ages 1-18 years of age, total UPF calories jumped to nearly 62%, and among adults ages 19 and older total UPF calories was 53%. In addition, families with lower mean income had a higher percentage of UPFs consumed per day: 54.7% for the lowest income group vs. 50.4% for highest income group.^[1]

UPFs are relatively inexpensive, convenient for use and aggressively marketed, particularly toward youth and under-resourced communities, often displacing healthier alternatives. This shift resulted in lowering the overall nutritional quality of typical eating patterns in the U.S. and is misaligned with the American Heart Association's dietary guidance.

This new Science Advisory reinforces current dietary guidelines from the American Heart Association to:

• Reduce the intake of most UPFs, especially those high in saturated fat, added sugars and sodium, and those that contribute to excessive calories; and
• Replace UPF consumption with healthier options like vegetables, fruits, whole grains, beans, nuts, seeds and lean proteins.

How are ultraprocessed foods classified?

UPFs are multi-ingredient foods containing additives (likely intended to enhance shelf life, appearance, flavor or texture) widely used in industrial food production and not commonly used in home cooking. Human diets are increasingly including more industrially processed foods, leading to various systems for classifying foods based on processing criteria. Multiple food classification systems exist currently; this Science Advisory focuses on the Nova framework for food classification. The Nova system, the most widely used, is based on the nature, extent and purpose of the food's industrial food processing. However, the Nova categorization does not consider the nutritional quality of foods. Certain types of industrial food processing are beneficial for preservation and safety, and/or lowering cost, such as techniques that extend shelf life, control microbial growth, mitigate chemical toxicants, preserve functional, nutritional and sensory (taste) qualities, and reduce food loss and waste.

Efforts to understand UPFs are hindered by differing definitions, limitations in dietary assessment tools and food composition databases, which often lack detailed information on additives and processing methods. Currently, U.S. manufacturers are not required to disclose processing techniques or cosmetic additive quantities, which contributes to the variability in risk estimates and confusion for consumers.

The writing group cautions that an overreliance on the degree of processing as a proxy for healthfulness of foods could sway the food industry to reduce or remove the markers of ultraprocessing from foods that are high in saturated fats, added sugars and sodium and promote them as "better-for-you alternatives."

Health Impact of UPFs

A meta-analysis of prospective studies cited in the advisory found a dose-response relationship between UPF consumption and cardiovascular events, such as heart attack, transient ischemic attack and stroke, Type 2 diabetes, obesity and all-cause mortality. High versus low UPF intake was linked to a 25%-58% higher risk of cardiometabolic outcomes and a 21%-66% higher risk of mortality. More research is needed to understand the appropriate thresholds for daily consumption of UPFs -- what a safe amount is and the incremental risks of eating more UPFs.

Research has also found that there may be underlying mechanisms that affect eating behaviors and obesity for some people, and that UPFs may promote obesity. UPFs frequently contain combinations of ingredients and additives that are uncommon in whole foods to enhance palatability and reduce cost, and these may influence reward-related brain activity. For example, ingredients like artificial flavors may mimic sweetness without sugar, and this disruption in flavor-nutrient relationships often leads to irregular eating habits, and results in weight gain.

Opportunities for research and policy

Balancing multiple priorities, including the practical need for a nutrient-dense, affordable food supply, current evidence supports the following key research and policy changes to improve public health and reduce risks related to UPFs:

1. Introduce approaches for individuals, food manufacturers and the retail industry that help shift eating patterns away from UPFs high in saturated fat, added sugars and sodium toward patterns high in vegetables, fruits, nuts, seeds, legumes, whole grains, nontropical liquid plant oils, fish and seafood, low-fat-low-sugar dairy, and, if personally desired, lean poultry and meats.
2. Enact multipronged policy and systems-change strategies (e.g., front-of-package labels) to help reduce intake of HFSS products.
3. Increase research funding to explore critical questions about UPFs: To what extent is it the ultraprocessing itself that makes a UPF unhealthy vs. the fact that ultraprocessed foods tend to have unhealthy ingredients? Most UPFs overlap with HFSS foods that are already targeted for cardiometabolic risk reduction, so a better understanding of the root causes of UPFs' link to poor health is fundamental to effective reduction strategies.
4. Enhance ongoing efforts to improve food additive science, including streamlined and efficient evaluation and regulation of food additives.

"More research is needed to better understand the mechanisms of how UPFs impact health. In the meantime, the Association continues to urge people to cut back on the most harmful UPFs that are high in saturated fats, added sugars and sodium, and excessive calories and instead follow a diet rich in vegetables, fruits, nuts, seeds and whole grains, low-fat-low-sugar dairy, and lean proteins like fish, seafood or poultry -- for better short- and long-term health," said Vadiveloo.

This Science Advisory was prepared by the volunteer writing group on behalf of the American Heart Association Council on Lifestyle and Cardiometabolic Health; the Council on Cardiovascular and Stroke Nursing; the Council on Clinical Cardiology; the Council on Genomic and Precision Medicine; and the Stroke Council. American Heart Association scientific statements and advisories promote greater awareness about cardiovascular diseases and stroke issues and help facilitate informed health care decisions. Scientific statements outline what is currently known about a topic and what areas need additional research. While scientific statements inform the development of guidelines, they do not make treatment recommendations. American Heart Association guidelines provide the Association's official clinical practice recommendations.

Notes

1. Ultra-processed Food Consumption in Youth and Adults: United States, August 2021-August 2023. National Center for Health Statistics. National Health and Nutrition Examination Survey. Data Brief No. 536. August 2025. U.S. Centers for Disease Control and Prevention https://www.cdc.gov/nchs/products/index.htm^[1].

Additional co-authors and members of the writing group include Vice Chair Christopher D. Gardner, Ph.D., FAHA; Sara N. Bleich, Ph.D.; Neha Khandpur, Sc.D.; Alice H. Lichtenstein, D.Sc., FAHA; Jennifer J. Otten, Ph.D., R.D.; Casey M. Rebholz, Ph.D., M.S., M.P.H., FAHA; Chelsea R. Singleton, Ph.D., M.P.H.; Miriam B. Vos, M.D., M.S.P.H., FAHA; and Selina Wang, Ph.D. Authors' disclosures are listed in the manuscript.

New research in mice suggests that muscle mass changes less than expected, but muscles may still get weaker, pointing out an urgent need for clinical studies to pin down the full effects of the popular medications.

"If we want to really help the individuals who may be losing muscle mass, then we need to know that they're actually losing muscle mass," says Katsu Funai, PhD, associate professor of nutrition and integrative physiology in the University of Utah College of Health and the senior author on the study. "We have data in mice that suggest that things are not as straightforward as they might seem."

The results are published in Cell Metabolism.

A weighty concern

Researchers found that Ozempic-induced weight loss did decrease lean mass by about 10%. Most of this lost weight wasn't from skeletal muscles but instead from other tissues like the liver, which shrunk by nearly half. The researchers emphasize that more research is needed to determine whether similar changes to organ size occur in humans -- and whether those changes come with any risks.

"Loss of mass in metabolically active organs, such as the liver, is expected as part of healthy weight loss," says Ran Hee Choi, PhD, research instructor in nutrition and integrative physiology at U of U Health and co-first author on the study. In both mice and humans, weight gain and loss can affect the size of organs like the liver without affecting their function. "It's unlikely that the observed lean mass loss represents a serious adverse effect," says Takuya Karasawa, PhD, postdoctoral researcher in the U of U Molecular Medicine Program and co-first author on the study.

Some skeletal muscles did shrink as the mice lost weight -- on average, by about 6%, not enough to explain the overall loss in lean mass. Other muscles stayed the same size.

Some of this loss in muscle mass is a return to baseline, the researchers say. Gains in fat also tend to lead to gains in skeletal muscle, since the body must do more work to move around. So loss of fat can lead to loss of muscle without affecting overall quality of life.

Size isn't strength

Interestingly, when the researchers tested the amount of force the mice's muscles could exert, they found that, for some muscles, strength decreased as the mice lost weight, even when the size of the muscle stayed roughly the same. For other muscles, strength was unchanged. It's unknown how weight loss drugs affect this balance in people, the researchers say.

A potential loss of strength when taking Ozempic may be of particular concern for adults over the age of 60, who are at higher baseline risk for muscle loss and reduced mobility. "The loss of physical function is a strong predictor of not just quality of life but longevity," Funai adds.

Clinical trials are needed

The researchers caution against extrapolating their results directly into humans, because mice and humans gain and lose weight in different ways. In people, obesity is associated with lower physical activity, but mice don't tend to become less active when they gain weight. And the mice in this study became overweight because they ate a high-fat diet, whereas people become overweight for a wide variety of reasons that include genetics, diet, sleeping patterns, and age.

Instead of drawing a one-to-one parallel with humans, the researchers say their results emphasize the need for more clinical studies. "There remains a significant need for validation in humans, especially concerning muscle strength," Karasawa says.

Funai adds that clinical trials should check for changes in muscle strength not just for Ozempic but also future weight-loss drugs. "There are many additional weight loss drugs that are in clinical trials and coming out in the next three to five years," Funai says. "But with all those clinical trials, if they're interested in measuring lean mass loss, they need to consider physical function."

"Our findings are really interesting, but this is a preclinical model," he adds. "We need these data in people."

The results were published in Cell Metabolism as "Unexpected effects of semaglutide on skeletal muscle mass and force-generating capacity in mice."

This study was supported by the National Institutes of Health, including the National Institute of Diabetes and Digestive and Kidney Diseases (grant numbers DK107397 and DK127979), the National Institute of General Medical Sciences (grant number GM144613), the National Institute on Aging (grant numbers AG074535, AG065993, AG076075, and AG086328), and the National Cancer Institute (grant number CA286584), as well as by the Grant-in-aid for Japan Society for Promotion of Science Fellows (grant number 24KJ2039). Content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.