Airfare could become cheaper due to people slimming down, a new theory suggests.

Analysts at Jeffries are predicting that the expanded use of GLP-1 obesity drugs may reduce fuel consumption, which could translate into lower costs for airplane tickets, as Fox Business has reported.

The Wall Street firm suggested that a 10% reduction in average passenger weight could lead to about a 2% savings in aircraft weight, 1.5% lower fuel costs and a 4% boost to earnings per share.

OLDER AMERICANS ARE QUITTING GLP-1 WEIGHT-LOSS DRUGS FOR 4 KEY REASONS

“A slimmer society = lower fuel consumption,” Jeffries reportedly wrote in a note to clients. “Airlines have a history of being vigilant around aircraft weight savings, from olives (pitless, of course) to paper stock.”

These predictions come as weight-loss drug options are growing and the first GLP-1 pill has hit the market, making the medication more accessible.

Gary Leff, a Texas-based travel industry expert and author of the blog “View From the Wing,” elaborated on this prediction in an interview with Fox News Digital.

“The heavier something is, the more fuel it burns,” he said. “If passengers weigh less, planes require less fuel to fly. If everyone went to the bathroom before they flew, they’d weigh less and burn less fuel, too.”

OBESITY EXPERT REVEALS THE BEST WAY TO DECIDE IF GLP-1S ARE RIGHT FOR YOU

“So, if average passenger weight declines, then flying the same plane on the same route will cost the airline less to operate,” he went on. “And in the most contestable markets, that will bring down fares, too, as airlines compete for passengers.”

Leff suggested that this won’t be true in all markets. Where the “supply of flights is constrained,” like in major cities, these lower costs are more likely to benefit the airlines than the passengers, as “costs fall, but fares do not.”

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From a clinical perspective, Dr. Krishna Vyas, a plastic surgeon in New York City, noted that under current conditions, the use of GLP-1 medications is “too limited, too uneven and too short-lived to meaningfully lower average passenger weight at a population level.”

“Most patients discontinue therapy within one to two years, and weight regain after stopping treatment is common, making durable, large-scale reductions in passenger mass unlikely,” he told Fox News Digital. “Even if modest fuel savings were realized, there is no evidence they would translate into lower ticket prices.”

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“GLP-1 medications represent a significant medical advance for individual cardiometabolic health, but extending their benefits to speculative effects on airline economics goes beyond what current clinical and population data support,” Vyas continued.

“Until broader access, durable adherence and sustained population-level outcomes are demonstrated, cheaper airfare should be viewed as a theoretical possibility — not a predictable consequence — of weight-loss drug use.”

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Dr. Peter Balazs, a hormone and weight loss specialist in New York and New Jersey, discussed how GLP-1s could potentially impact the in-flight experience.

“Patients on GLP-1s experience reduced cravings for carbohydrates and a heightened preference for protein and fats,” he said. “Airlines may need to reconsider in-flight menus to cater to this growing demographic, offering more high-protein, low-carb options.”

Balazs noted that weight-loss medications can lead to gastrointestinal side effects, including GERD, dyspepsia, nausea and vomiting.

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“From a medical standpoint, I would suggest loading up on antiemetics (medications that prevent or relieve nausea and vomiting),” Balazs shared as advice to the airlines. “Furthermore, I would counsel patients not to initiate therapy or administer a first dose shortly before a flight to avoid severe side effects at altitude.”

A common vitamin found in everyday foods may play a role in how often people go to the bathroom, according to a large new study.

Researchers found evidence that vitamin B1, also known as thiamine, is linked to gut motility, which is the process that moves food through the digestive system.

The international team — led by Mauro D’Amato, a professor of medical genetics at LUM University and a research professor at CIC bioGUNE — analyzed genetic and health data from more than 268,000 people of European and East Asian ancestry, according to a press release.

EXPERT WARNS OF ‘SILENT EPIDEMIC’ THAT PUTS MEN’S HEALTH AT SERIOUS RISK

Participants reported how frequently they went to the bathroom, which researchers used as a practical measure of gut motility.

“We used genetics to build a roadmap of biological pathways that set the gut’s pace. What stood out was how strongly the data pointed to vitamin B1 metabolism, alongside established mechanisms,” first author Dr. Cristian Diaz-Muñoz, a postdoctoral researcher in the Gastrointestinal Genetics Lab at CIC bioGUNE, located in the Bizkaia Science and Technology Park in Spain, said in the release.

B1, also known as thiamine, is linked to gut motility, which is the process that moves food through the digestive system. By scanning millions of genetic markers, the team identified 21 genetic regions tied to how often people had bowel movements, including several that had not previously been connected to digestive function.

GUT IMBALANCE MAY BE DRIVING AMERICA’S FOOD ALLERGY EPIDEMIC, EXPERTS WARN

Many of the signals pointed to pathways already known to be important for digestion, like bile acid metabolism and nerve signaling, which control the rhythmic contractions of intestinal muscles, the release stated.

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The most unexpected finding involved genes linked to thiamine metabolism. Two genes in particular, which help to transport and regulate vitamin B1 in the body, showed strong associations with stool frequency.

To explore whether this translated into everyday behavior, the researchers examined dietary data from nearly 100,000 participants in the UK Biobank.

They found that people who consumed higher amounts of vitamin B1 tended to have more frequent bowel movements.

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However, this relationship wasn’t seen in every case. The effect changed depending on a person’s genetic makeup, suggesting that genes are involved in the body’s processing of the vitamin.

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Vitamin B1 plays a central role in energy metabolism and nerve function, including the nerves and muscles that coordinate movement in the gut, according to the National Institutes of Health.

Study limitations

The study, which was published in the scientific journal Gut, did have some limitations.

Frequency is an indirect measure of gut motility and does not capture stool consistency, discomfort or other symptoms relevant to digestive disorders, the researchers acknowledged.

The study also relied on self-reported dietary data, which can be imprecise.

Genetic associations do not prove cause and effect, the researchers noted. 

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The results do not conclusively show that taking vitamin B1 supplements will change bowel habits, nor do they establish the biological pathway through which thiamine might influence digestion.

People experiencing digestive issues should consult a doctor for guidance.

This story discusses suicide. If you or someone you know is having thoughts of suicide, please contact the Suicide & Crisis Lifeline at 988 or 1-800-273-TALK (8255).

Bunnie XO, the wife of country singer Jelly Roll, is discussing how a weight-loss medication may have led to her experiencing a “dark” depression.

During an episode of her podcast “Dumb Blonde,” Bunnie, whose real name is Alyssa DeFord, revealed that she had been taking a new drug by Lilly called retatrutide (reta), which is currently in late-stage trials and not approved by the FDA.

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Bunnie, 45, confirmed that she received her dose from a “reputable wellness center” in Nashville, and felt sick within the first week. Within two weeks, she noticed she looked and felt slimmer. In the fourth week, she increased her dose by one unit, which is when she noticed the “mental numbness.”

“I literally got sent into the worst suicidal depression that I’ve had since 2020,” she said. “I’m talking like it scared me so bad. I didn’t think I was going to make it through the two weeks. Like I was praying to God.”

The podcaster shared how she had “no emotion” and couldn’t listen to music that would typically “bring me joy.”

“You could see like my eyes were black,” she said. “I just drove in silence because I just couldn’t handle anything. It was either overstimulating or it was to the point where it just stole my joy. I had no joy, like nothing to live for. It was so dark.”

OBESITY EXPERT REVEALS THE BEST WAY TO DECIDE IF GLP-1S ARE RIGHT FOR YOU

After 20 days off the drug, Bunnie reported that her joy is “finally” returning, calling the experience a “battle.”

“My story is not what’s going to happen to you,” she shared with her listeners. “There’s so many people who are taking reta and love it and all that. But something happened with me.”

Indiana-based drug-maker Lilly confirmed in a statement to Fox News Digital that retatrutide is an “investigational molecule that is legally available only to participants in Lilly’s clinical trials.”

“No one should consider taking anything claiming to be retatrutide outside of a Lilly-sponsored clinical trial,” the spokesperson wrote. “This was not a Lilly product, and the company continues to warn the public about the potential dangers of fake medicines.”

“This was not a Lilly product and the company continues to warn the public about the potential dangers of fake medicines.”

Fox News senior medical analyst Dr. Marc Siegel reacted in an interview with Fox News Digital, warning that retatrutide should not be taken while it has still not received FDA approval unless it is part of a clinical trial.

“This drug is new — known as a triple agonist (GLP-1, GIP and glucagon receptor agonist),” he said. “[It] has been linked potentially to depression and suicidal thoughts, as have the GLP-1 drugs, where some studies have shown increased psychiatric risks, so there is a potential link here.”

What is retatrutide?

The drug has received the nickname “GLP-3” because it targets the three hormones, which experts suggest could lead to more substantial weight loss.

Lilly announced results from its phase 3 trial TRIUMPH-4 in December, which tested retatrutide’s effect on weight loss and other health conditions.

Participants with obesity and knee arthritis who took a 12-mg dose of retatrutide saw an average weight loss of 71.8 lbs (28.7%) at 68 weeks.

“We believe retatrutide could become an important option for patients with significant weight loss needs and certain complications, including knee osteoarthritis,” a Lilly spokesperson said in a statement to Fox News Digital.

Seven additional phase 3 trials for retatrutide are expected to wrap up in 2026. The drug could see FDA approval in 2027, according to GoodRx.

STUDY REVEALS HOW RAPIDLY WEIGHT COMES BACK AFTER QUITTING OBESITY MEDICATIONS

Despite limited data availability on the drug, the medication could also be applied to treat other conditions like type 2 diabetes, kidney disease, cardiovascular risk reduction and metabolic dysfunction, according to GoodRx and other experts.

Siegel confirmed that retatrutide’s side effects can be similar to other GLP-1s, including gastrointestinal symptoms and other rare reactions like pancreatitis, gallstones and heart arrhythmia.

Philip Rabito, M.D., a specialist in endocrinology, weight loss and wellness in New York City, shared in a previous interview with Fox News Digital that this new class of weight-loss drugs is positioned to “approach bariatric surgery level outcomes” — although it doesn’t come without risks.

“The novel glucagon‑agonist component introduces less‑understood long‑term safety considerations, so it is imperative that patients are followed closely by healthcare professionals experienced with this class of medicines, with cautious, stepwise use, despite the impressive efficacy,” he cautioned.

The mental health connection 

The potential link between mental health symptoms and weight-loss drugs is most likely due to the impact on the brain’s reward system, according to Siegel.

“Dopamine, serotonin and norepinephrine affect mood and appetite, reduce cravings and can have a positive effect on mood, but also can be negative,” he said. “Somewhat unpredictable.”

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Dr. Peter Balazs, a hormone and weight-loss specialist in New York and New Jersey, noted that any presentation of significant depressive symptoms, particularly those including “psychotic features and suicidal ideation,” requires a full clinical evaluation.

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“It is essential to understand the patient’s complete medical and psychiatric history, including other medical conditions, precise weight change dynamics, concomitant medications and psychosocial stressors,” he said. “Major depressive episodes are multifactorial — attributing them to a single agent without this context is premature.” 

Any individual experiencing these symptoms should “seek immediate professional help,” Balazs said.

“We are still learning about the psychiatric effects of these medications, even the ones that have already been approved,” he added.

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Bunnie’s age would typically place her in the perimenopausal stage, which can include “significant fluctuations” in reproductive hormones like estrogen, Balazs noted.

“Estrogen has well-documented neuroprotective and mood-stabilizing effects,” he said. “Its decline can render the brain more vulnerable to stress and dysregulation, potentially precipitating or exacerbating depressive episodes.”

Obesity can also cause hormone shifts and inflammation that can interfere with normal brain function, sometimes affecting mood and emotional balance, the expert noted.

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Balazs stressed that experts should be “vigilant” in monitoring symptoms of people taking these medications. 

“Until a protocol is established, patients outside clinical trials should not inject these medications,” he cautioned. “Dose and dose-related responses can change the whole experience.”