Baby-led weaning: A solid approach to infant nutrition

 

KEY TAKEAWAYS

• New CSU research shows infants following baby-led weaning grow at the same pace as those following conventional weaning.
• The scientific assessment is the first of its kind and provides evidence that baby-led weaning could support healthy growth and development.
• The study addresses worry among many parents and caregivers about a weaning approach that has been popularized in part by social media.

When it’s time to add solid food to a baby’s diet, is it best to spoon feed purées – the conventional approach – or to allow the baby to feed herself soft finger foods?

The second path, called baby-led weaning, has exploded in popularity in the past decade, yet many parents and caregivers worry about whether it results in healthy growth or could have negative effects.

Colorado State University nutritionists are settling the question, with implications for an untold number of babies. The researchers assessed 150 infants from the age of 6 months to 1 year to compare baby-led weaning and a typical puréed weaning diet and found that babies in the two groups acquired similar calories and nutrition and grew at the same pace.

The study is the first to correlate dietary and growth data and to scientifically compare growth outcomes from the two weaning approaches. It did not assess specific health indicators, but findings suggest healthy growth and development are attainable if baby-led weaning relies on a variety of healthy foods.

 “These findings reassure parents and caregivers that babies following baby-led weaning grow at the same rate as babies following conventional weaning,” said Minghua Tang, a professor and the Lillian Fountain Smith Endowed Chair in Nutrition in CSU’s Department of Food Science and Human Nutrition.

Tang and her doctoral student, Kinzie Matzeller, conducted the research with colleagues at the University of Colorado Anschutz Medical Campus and published their findings June 24 in the Journal of the Academy of Nutrition and Dietetics.

“Baby-led weaning is so popular, but we didn’t have that much research-based evidence about whether it was superior to conventional weaning or whether it might do harm,” Tang said. “These findings are helping fill a gap by showing that babies following baby-led weaning grow at the same trajectory as those weaned with spoon feeding.”

It’s rewarding to provide parents and caregivers with evidence-based information rather than anecdotes, Matzeller said.

“I feel a relief to be able to rely on research and optimistic that parents might not have to worry about healthy growth if they opt for baby-led weaning,” she said.

Proponents of baby-led weaning, including social media influencers, note that the approach encourages babies to eat the same foods their families eat; to regulate their intake based on hunger cues, which can lead to healthy, long-term eating habits; and to improve fine-motor skills, which boost neurological development.

There are important caveats that make baby-fed weaning successful, Tang said. Among them: Babies must be developmentally ready to feed themselves, must eat sufficiently soft foods cut into small pieces to avoid choking and must be offered a healthy diet.

Solid food is typically introduced when a baby is about 6 months old, when the infant is still ingesting breast milk or formula to meet most of her nutritional needs. By age 10 months to 1 year, most babies get about half their nutrition from solid foods, Tang said.

The new study has several distinctive aspects:

• It specifically defined baby-led weaning as relying on less than 10 percent puréed foods, rather than depending on general descriptions from parents and caregivers.
• It analyzed dietary records to pinpoint calories and nutrition consumed per day.
• It linked dietary intake with growth data each month of the study to understand and compare the effects of baby-fed weaning and conventional weaning.

This quantitative, or data-based, dietary assessment yielded objective findings that parents and caregivers may rely upon when making weaning decisions.

Although baby-led weaning has surged in popularity in recent years, it reflects the way most families fed babies before processed food became a norm, Matzeller noted. Now, blended baby food is commonly available in jars and pouches.

The baby-led weaning study is an outgrowth of a larger research project Tang leads called the Maternal and Infant Nutrition Trial, an 18-month investigation into how different protein-rich foods affect growth and gut health in babies. The trial is funded by the National Institutes of Health.

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Journal

Journal of the Academy of Nutrition and Dietetics

DOI

10.1016/j.jand.2026.156376 

Currently approved mRNA vaccines are safe and effective

• A comprehensive new review that assessed billions of doses of currently approved mRNA vaccines affirms that these vaccines provide protection against COVID-19, including severe COVID-19, across diverse populations, including children, pregnant women, and immunocompromised people. Booster doses extended and strengthened protection for existing SARS-CoV-2 subvariants through May 2023.
• The review reinforces existing evidence that mRNA vaccines are safe; serious adverse events are rare and substantially outweighed by protection against severe disease, hospitalisation, and death.
• The review also highlights that mRNA technologies have potential future uses for vaccines against influenza, RSV, and other infectious diseases, as well as for personalised cancer vaccines and RNA-based therapeutics.
• The authors emphasise the importance of equitable access, strengthened and expanded manufacturing to low- and middle-income countries, and advanced storage and distribution for mRNA vaccines.
• The authors also call for continued clear communication about mRNA vaccine safety and effectiveness to sustain public trust, improve vaccine uptake worldwide, and address ongoing misinformation about mRNA vaccines.

A comprehensive new review published in The Lancet affirms that currently approved mRNA vaccines are safe and highly effective at preventing infectious diseases, including COVID-19. The new review also suggests that mRNA vaccine technologies have potential as new options for treating and preventing other health conditions and diseases, including influenza, RSV, cancer, and autoimmune conditions.
 
Through detailed analysis of published data from laboratory research, clinical trials, and real-world surveillance of billions of mRNA vaccine doses, the authors assessed the science behind mRNA vaccines and their public health impact.
 
The review concludes that serious adverse side effects from mRNA vaccines remain exceedingly rare. For example, in real world surveillance, incidents of myocarditis and pericarditis (heart-related inflammation) following vaccination were higher among second-dose recipients, with rates of roughly 12.6 cases per million for Pfizer BioNTech’s BNT162b2 vaccine and about 35.6 cases per million for Moderna’s mRNA-1273. Importantly, the increased risk of myocarditis and pericarditis from mRNA COVID-19 vaccines, particularly in males aged 12-19, was significantly lower than the risk of developing myocarditis or pericarditis from a SARS-CoV-2 infection. Other serious adverse events were also very rare. For example, the risk of anaphylaxis was 4.7 cases per million doses (Pfizer), and Guilain Barre Syndrome was 38 cases per million doses (AstraZeneca) [see table]. Most other side effects, such as sore arms, fatigue, or fever, were mild to moderate and subsided after a few days.
 
The analysis found that across various clinical trials and real-world data, mRNA vaccines are about 87% effective against any documented SARS‑CoV‑2 infection, 93% effective against hospitalisation, and 94% effective against mortality within 14–42 days after vaccination. Effectiveness waned over time and, in some analyses, was reduced by age and against the Omicron lineage (67% against infection and 72% against hospitalisation), but booster doses helped restore protection. Ongoing surveillance and real‑world monitoring continue to support the vaccines’ tolerability and effectiveness as new variants emerge, and booster programs are implemented to maintain protection.
 
“Our comprehensive review provides compelling evidence confirming that approved mRNA vaccines are safe and highly effective. Throughout the COVID-19 pandemic, mRNA vaccines demonstrated what rapid, science-driven collaboration can achieve by delivering safe, effective protection at an unprecedented scale. The key lessons from mRNA vaccine use during the COVID-19 pandemic are not only about manufacturing speed, but about the importance of sharing safety data, conducting ongoing rigorous real-world surveillance, and providing clear information about how new types of vaccines work and why they protect communities," said lead study author Dr Anna Blakney of the University of British Columbia (Canada).
 
mRNA platforms for future disease prevention and treatment
 
mRNA vaccines deliver genetic instructions to human cells to manufacture harmless viral proteins that train the immune system to recognise and fight the real virus. This process is temporary and ends once the body has learned to defend itself; it does not change a person’s DNA. The first FDA-approved mRNA vaccines were introduced during the COVID-19 pandemic [1], building upon decades of research to quickly scale up approval, production, and distribution.
 
Beyond COVID-19, the authors emphasise the versatility of the mRNA platform. Efforts are underway to develop vaccines against influenza, RSV, and other infectious diseases, as well as personalised cancer vaccines and RNA-based therapeutics (see figure 2 for trials underway). This breadth of potential applications signals a future in which mRNA technology could be tailored to individual patients and specific disease threats, offering rapid, flexible, and effective tools for public health.
 
“As the world continues to confront evolving infectious threats, our review underscores the need for sustained innovation, robust surveillance, and true global collaboration to maximise the life-saving benefits of this groundbreaking technology. mRNA vaccines have already transformed how we respond to emerging diseases, and with ongoing innovation and rigorous safety monitoring, they can drive progress in preventive medicine and cancer treatment for years to come,” said co-author Dr Manish Sadarangani of the University of British Columbia and BC Children’s Hospital Research Institute (Canada).
 
Expanding global access and equity
 
The authors also highlight that improvements in mRNA vaccine formulation and distribution enhance access and equity, as higher-temperature storage extends shelf life and lowers costs, broadening distribution.

Because mRNA vaccines are based on a common platform and can be adjusted to new targets much faster than other vaccine platforms, the manufacturing process is scalable and tightly controlled to keep the RNA pure and effective. Across the supply chain, vaccines are kept in specialised freezers and temperature-controlled settings, and newer storage options, such as higher-temperature storage and freeze-drying, are helping more vaccines reach remote places quickly and reduce waste. This combination helped speed up COVID-19 vaccine development and distribution.
 
"Expanding manufacturing capacity and ensuring equitable access in low- and middle-income countries is essential if mRNA vaccines are to fulfill their promise as a global public good. By investing in technology transfer, local production, and robust regulatory systems, we can shorten supply chains, reduce costs, and ensure that people everywhere benefit from safe, effective vaccines beyond pandemics," said co-author Dr Robin Shattock of Imperial College London (UK).
 
The authors note the importance of ongoing post-licensure safety monitoring and long-term follow-up to study post-marketing real-world performance of existing licensed mRNA vaccines. They also emphasise the importance of documenting all instances of side effects, no matter how rare, as some signals might be missed or misinterpreted in real-world observational studies. Additional study limitations include that the review’s findings come from many different countries and programs, so results may vary by population, vaccine product, and how safety data are collected. Finally, the ongoing evolution of viruses means that effectiveness might change with new variants.
 https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(26)00512-X/fulltext

Risk of falls, adverse events higher for older adults prescribed sedatives

 

Older adults discharged from hospital with a new prescription for a sedative, especially a benzodiazepine or antipsychotic, are at increased risk of falls and other negative consequences, according to new research published in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/lookup/doi/10.1503/cmaj.251965.

“Our results showed that discharging older adults after an acute care hospital stay with a new prescription for these medications was associated with an increased hazard of falls requiring medical attention, further need for acute hospital care, and death in the 30 days after hospital discharge, whereas individuals with prior exposure did not experience the same increased hazards,” writes Dr. Lisa Burry, clinician scientist at Mount Sinai Hospital, Sinai Health and University of Toronto, Toronto, Ontario, with coauthors.

Falls are a major public health burden and affect older adults in particular. Sedatives and antipsychotics are associated with adverse events, and clinical guidance discourages prescribing these potentially inappropriate medications for older adults.

The study of more than 1.86 million adults aged 66 years and older aimed to understand prescribing patterns to inform discharge prescribing in future. Based on ICES data, it looked at all patients discharged from hospital between April 2003 and August 2023. In total, 13% (246 440) filled at least 1 prescription for any sedative within 7 days of discharge, and about one-third (76 335) of them had not filled a prescription for a sedative within the 6-month period before hospitalization. The risk of falls was 20% higher in people with a new sedative prescription, and the risk of an emergency department visit, readmission, and death within 30 days was also increased. 

“Although the overall absolute magnitude of the risk of adverse events identified was modest from a population perspective, the effects on patients and their families are clinically and socially important,” write the authors. “Moreover, given the volume of hospital admissions among older adults and the aging population, a modest increase in risk translates into a large impact on the health care system.”

The authors suggest caution when prescribing these medications on hospital discharge, ensuring medical follow-up 1 to 2 weeks after discharge to monitor patients, continue risk assessment, and review the need for the prescription.

“Given the identified associations, clinicians must consider whether new sedative prescriptions are essential or can be deprescribed or de-escalated before or shortly after hospital discharge. When ongoing sedative use is required, community support, such as falls or mobility assessments, and ongoing medication reviews may help mitigate risks,” the authors conclude.

Almost 9 out of 10 adults don’t know risks of eating hot dogs

 As Fourth of July party planning gets underway, a new Physicians Committee for Responsible Medicine/Morning Consult survey finds that while nearly half of Americans say they eat hot dogs two or three times each month, nearly 90% say they are unsure or unaware of the specific health risks associated with the consumption of processed meat.

The poll included 2,201 U.S. adults surveyed June 22-24, 2026. When asked, “In the past 12 months, approximately how frequently have you eaten at least one hot dog?” 59% answered daily to once per month. When asked “What, if any, health risks are there from eating hot dogs?” 49% said “I’ve heard there are health risks but I’m unsure of what they are specifically,” while another 40% said “I don’t know of any health risks from eating hot dogs.”

An estimated 150 million hot dogs are consumed on Independence Day alone, enough to stretch from Washington, D.C., to Los Angeles more than five times, according to the National Hot Dog and Sausage Council.

Stephanie McBurnett, a registered dietitian with the Physicians Committee, said she’s particularly concerned about kids’ consumption of hot dogs and other processed meats.

"Because children's bodies and eating habits are still developing, early and frequent exposure to red and processed meats — like hot dogs — can cause lasting harm,” she said. “Alarmingly, colorectal cancer rates among young people are rising, with diagnoses occurring at increasingly earlier ages."

An analysis of data from the Centers for Disease Control and Prevention found that between 1999 and 2020, the rate of colorectal cancer grew 500% among children ages 10 to 14, 333% among teens ages 15 to 19, and 185% among young adults ages 20 to 24.

The World Health Organization has determined that consuming processed meat, such as hot dogs, increases the risk of colorectal cancer and has classified it as “carcinogenic to humans.” Just 50 grams of processed meat — the amount in a single hot dog —consumed daily increases colorectal cancer risk by 18%. The World Cancer Research Fund and the American Institute for Cancer Research say that “there is strong evidence” that consumption of processed meat causes colorectal cancer.

The National Cancer Institute concurs, saying “There’s mounting evidence linking an unhealthy diet — in particular, one high in processed meat and fat, and low in fruits and vegetables — to early-onset colorectal cancer.”

According to “Cancer statistics 2024: All hands on deck,” a report from the American Cancer Society, colorectal cancer was the fourth leading cause of cancer death in the 1990s and has risen to the leading and second leading cause of cancer death in men and women, respectively, aged 40-49. Colorectal cancer has also moved up to the leading cause of cancer death in men aged 20-39 years and the third leading cause in women in the same age group.

In the new Physicians Committee poll, when told “Hot dogs are processed meats, and frequent consumption is linked to serious health risks, including colorectal cancer, type 2 diabetes, and heart disease” and then asked, “If a veggie dog (plant-based hot dog) were available, how likely would you be to choose it instead of a hot dog?” 22% answered “very likely” while 24% said “somewhat likely.”

Replacing meat with plant-based meat alternatives may benefit heart health, while processed meats such as hot dogs are linked to heart disease risk.

Numerous studies show the benefits of consuming whole grains, fruits, vegetables, and beans and legumes. Although they are processed, recent research suggests that many plant-based meat alternatives may also have positive health impacts.

“On the bright side,” McBurnett said, “there are a multitude of healthier hot dog alternatives available these days, from commercially prepared veggie dogs that can be found in most supermarkets, to tasty whole food homemade versions made from marinating carrots in soy sauce, liquid smoke, and spices.

“At the end of the day,” McBurnett said, “the toppings are what make a hot dog taste great, from your favorite condiments to pickles, peppers, onions, protein-packed chili beans, and gut-friendly sauerkraut — all things that load on both flavor and nutrition.” 

Same day administration of COVID-19 & flu vaccines: no increase in adverse events

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What is the problem and what is known about it so far?

Safety studies of the original COVID-19 vaccine found infrequent but widely reported adverse events. In recent years, the COVID-19 vaccine has been updated several times, which may change the risk for adverse events in the United States, where most of the population has acquired some immunity to COVID-19.

Why did the researchers do this particular study?

The authors wanted to examine risks for adverse events within 90 days after receipt of 3 newer types of COVID-19 vaccines, along with the influenza vaccine, in comparison with receipt of only the influenza vaccine.

Who was studied?

The study used data from the U.S. Department of Veterans Affairs electronic medical records to identify persons who received COVID-19 and seasonal influenza vaccines at the same visit or received only the influenza vaccine between September 1, 2022, and August 26, 2025.

How was the study done?

This study simulated (or emulated) a randomized trial using real-world data and analytic methods to compare adverse events after COVID-19 plus influenza vaccines versus only the influenza vaccine. During the study time frame, 12,344,082 veterans had a primary care visit; after exclusions such as a recent COVID-19 infection or documented refusal, 2,518,329 veterans who received the influenza vaccine were studied, of whom 705,124 received both vaccines and 1,813,205 received only the influenza vaccine. Analytic methods were used to balance these 2 study groups. Each veteran could be studied up to 3 times when different updated COVID-19 vaccines were offered: 2022 to 2023, 2023 to 2024, and 2024 to 2025. The authors examined 46 adverse events occurring within 90 days and grouped them by severity.

What did the researchers find?

For the 2 more severe categories of adverse events, the risks were similar for the 3 updated types of COVID-19 vaccines when given with the influenza vaccine compared with only influenza vaccination. For the less severe group of adverse events, there was a small increase in syncope (fainting) and a small decrease in tinnitus (ringing in the ears), but these risks were not statistically significant.

What were the limitations of the study?

This was not an actual randomized trial, so there may be unmeasured factors that could have affected outcomes. Most study participants were men.

What are the implications of the study?

The study found that the short-term risks for adverse events were similar for persons receiving both COVID-19 and influenza vaccines compared with the influenza vaccine alone. This study offers reassurance about the safety of receiving the newer COVID-19 vaccines with the influenza vaccine at the same time.

 

Healthy but sedentary individuals: higher risk for cancer, diabetes, Alzheimer’s

 Researchers at the University of Colorado Anschutz have found that healthy yet sedentary individuals show a significant, coordinated drop in muscle mitochondrial function that may precede the development of major diseases like cancer, diabetes, and Alzheimer’s.

“Mitochondrial function is the center of metabolic health,” said the study’s senior author Iñigo San Millan, adjoint assistant professor in the Division of Endocrinology, Metabolism and Diabetes at CU Anschutz. “If you are 40, healthy, and sedentary, it is likely that you already have something going on inside your cells that will likely come back to haunt you in 10 or 15 years.”

The study specifically noted that mitochondria, which process energy within cells, showed a significantly decreased capacity to burn both sugar and fat in healthy individuals who get less than the recommended 150 minutes of exercise a week. Researchers also found that sedentary muscle contained about half as much of a key protein needed to convert sugar into usable energy.

The protein, MPC1, transports a key byproduct of sugar breakdown into the mitochondria.

The study, published Friday in Clinical Bioenergetics, examined nine sedentary and ten regularly active men, approximately 42-years-old. A companion study on women is currently being planned. Researchers analyzed muscle biopsies to observe how efficiently the mitochondria burned fuel and performed exercise tests to measure fitness, fat-burning capacity and blood lactate levels—a key marker of how hard the body has to work for energy.

When compared to the active group, sedentary men showed significant cellular deficits:

• Mitochondrial Efficiency: Dropped by 28% to 36% across several categories.
• Fuel Transport: The MPC1 protein was 49% lower, reducing the muscle's ability to burn sugar. Similarly, the CPT1 enzyme, which transports fats into the mitochondria, was roughly half as active.
• Cardiovascular & Blood Markers: Sedentary men had a 38% lower maximal oxygen use (VO2​max) and accumulated 60% higher levels of lactate in their blood during exertion.

San Millan said this represents a fundamental shift in cellular identity. Sedentary people aren't just "out of shape"—their cells are losing the ability to process fuel efficiently. For example, the massive drop in MPC1 could be one of the earliest signs of the cellular traffic jams that eventually cause insulin resistance and type 2 diabetes.

San Millan, a renowned physiologist known for his work in elite sports performance, including with Tour de France champion Tadej Pogačar, noted that the study highlights how regular exercise acts as a literal shield for cellular health, helping mitochondria seamlessly switch between burning fat and carbohydrates, a term that is called metabolic flexibility.

“Being sedentary will progressively erode metabolic health. When you stop moving, you lose that cellular identity of being healthy, and your body begins moving toward disease,” San Millan said.

The research team hopes to conduct larger, more diverse trials in the future and run training or drug trials to see if MPC1 and CPT1 can recover with intervention.

“This cellular decline is something we can actually test for in a non-invasive way, through cardiopulmonary exercise testing and lactate testing,” San Millan said. “And if we catch it early, we can prescribe targeted exercise programs designed to restore mitochondrial health and potentially prevent future disease.”

GLP-1–Induced Weight Loss and the Female Obesity Penalty

 GLP-1 medications generate large weight loss and may also alter social and economic outcomes. Using the Understanding America Study, this study compares women starting GLP-1s for weight loss with matched women who would like to start a GLP-1 but have not. 

Single women’s marriage/cohabitation rates rise by 29 percentage points and employment among baseline non-employed women rises 27 percentage points after six or more quarters. 

Existing partnerships do not dissolve, and already-employed women show no upward job mobility. 

The pattern suggests that part of the female obesity penalty operates at new-match formation rather than only through health or incumbent productivity.