On Oct. 10, more than a thousand employees at the CDC received reduction-in-force notices, coinciding with the government shutdown that began earlier in the month. The Department of Health and Human Services reinstated 600 staff within 24 hours, citing “data discrepancies and processing errors,” but the planning division responsible for designing and coordinating the National Health and Nutrition Examination Surveys (NHANES) remained furloughed.

“The recent layoffs of the entire Planning Branch within CDC’s Division of Health and Nutrition Examination Surveys threaten future NHANES cycles and the nation’s ability to monitor and understand critical health and nutrition trends,” the American Society for Nutrition (ASN) shared in a statement following the layoffs. “Without them, this foundational resource and the evidence it provides for science, policy and public health are at risk.”

ASN has called on the administration to immediately rescind the firing of the CDC National Center for Health Statistics (NCHS) employees, stressing that “NHANES is essential to the nation’s health and nutrition research enterprise.”

Since the Trump administration took office in January, the CDC has lost around 3,000 employees, equivalent to approximately a quarter of its staff.

The contributions of NHANES

Launched in the early 1970s, NHANES grew out of earlier NCHS efforts to assess the health of the U.S. population. It is now a cornerstone of U.S. public health infrastructure—used to evaluate the evolving health and nutritional status of adults and children across decades and the nation through a combination of interviews, physical examinations and lab tests conducted at mobile examination centers.

“NHANES data are used to guide federal policymaking in areas including food labeling, food fortification, food safety, dietary guidance, tracking progress toward national nutrition and health objectives and establishing nutrition research priorities,” the ASN noted. “The survey influences billions of dollars in federal investments and is essential to nutrition and health research, policy and programs.”

The growing sophistication of survey data—through genetic information, advanced biomarkers and targeted sampling of underrepresented groups—continues to deepen research and inform hot-button policy issues including obesity, diabetes, heart disease, nutrient intake and deficiencies, and exposure to toxins like heavy metals, pesticides and forever chemicals.

“NHANES is foundational to understanding the relationship of the U.S. diet to health and disease,” said Connie Weaver, distinguished research professor of nutrition science at San Diego State University, California. “It is the basis for determining What We Eat in America that is used as a milestone for evaluating how well Americans are following the Dietary Guidelines for Americans—this gives guidance to food programs and health care professionals for deciding nutrients of public health concern to emphasize or limit.”

In her own research, she has collaborated with NHANES experts to study nutrient intake from processed foods and dietary supplements, the effects of diet on bone health, blood pressure and hypokalemia, and more recently, trends in calcium bioavailability and osteoporosis as U.S. diets become more plant forward.

Sergej Ostojic, PhD, a leading biomedical scientist and head of the Applied Bioenergetics Lab at Novi Sad University in Serbia, has used NHANES as essential data source, particularly in linking dietary creatine intake to health and establishing reference intakes across ages and demographics.

“By integrating NHANES analyses with experimental trials, my research demonstrates how large-scale survey data can guide hypothesis generation, contextualize intervention outcomes and inform nutritional policy related to human metabolism and healthy aging,” he said.

The consequences of a model lost

Notwithstanding the impact of broader reductions in CDC force on the nation’s capacity to respond to public health emergencies, for nutrition scientists and supplement industry trade organizations consulted, the elimination of the NHANES planning division undermines evidence-based policy and rolls back decades of progress towards understanding the link between diet and health.

“NHANES data is the sole source of information needed to keep everything from the U.S. dietary guidelines to pesticide tolerances up to date,” said Robert Marriott, vice president of regulatory & government affairs at the American Herbal Products Association (AHPA). “Other research and federal data systems depend on fresh NHANES numbers to function. Without new NHANES data, we stop knowing what policy should be or what effects it is having.”

He added that the survey—arguably the most robust source of data on the relationship of food and human health—is uniquely well-suited to track diet and childhood chronic disease, and that without it, it would be “extremely challenging to accurately document the successes of the MAHA strategy.”

Dr. Weaver also commented that NHANES has served as the model for the world, providing a benchmark for public health data collection that supports both national and international policy development.

“Many researchers from other countries ask questions about diet and disease relationship on these U.S. data because they lack their own surveys,” she said. “I would despair if we fell from being the model for the world to no better at understanding what our citizens eat than developing countries.”

Dr. Ostojic echoed these sentiments, noting that the loss of the only longitudinal, nationally representative dataset of this kind would severely restrict evidence-based policymaking, disease surveillance and the evaluation of nutrition programs in the U.S., while also disrupting international comparability.

“Losing it would substantially weaken the foundations of nutrition research and public health monitoring worldwide,” he said. “I hope this will never happen and that this invaluable database will remain accessible to all scientists interested in advancing populational health.”

The Council for Responsible Nutrition (CRN) highlighted that the survey has historically provided crucial information on nutrient intake and nutrient status, and how dietary supplements contribute to these measures.

“Any disruptions to NHANES could have a negative impact on public health and the ability to assess nutrient status, healthy eating patterns and supplement use,” said Andrea Wong, PhD, senior vice president of scientific & regulatory affairs at CRN. “At a time when the country is focused on improving overall health and nutrition, policy makers and researchers will have to rely on other, less credible and less objective measures to ascertain this data.”

The food you eat has a profound and reciprocal impact on your brain. While a diet heavy in processed foods, saturated fats, sugar and too much salt significantly raises the risk of cognitive decline and neurodegenerative diseases like dementia, a smart diet offers comprehensive protection.

A “good” diet safeguards your brain by supplying essential nutrients and antioxidants that protect nerve cells, support neuroplasticity – the ability to form new connections – and drastically cut down on inflammation, which is a primary driver of brain ageing.

The Mediterranean diet is a way of eating centred on minimally processed foods, featuring a diverse array of plants and healthy fats.

The Green Mediterranean diet builds on that model, Hong Kong-based functional nutritionist Beth Wright says. It maintains the same foundation but incorporates more polyphenol-rich foods, such as green tea, walnuts and Mankai duckweed, which deliver many brain-health benefits.