Medical Bulletin 10/January/2026

GLP-1 receptor agonists—medications like Ozempic, Wegovy, Mounjaro, and Zepbound—mimic a natural gut hormone that signals fullness to the brain while slowing digestion and boosting insulin release. They've transformed weight loss for millions, with over 15 million Americans now using them. However, obesity is a chronic condition, and the Oxford team wanted to understand what happens when patients stop treatment and how this compares to behavioral approaches like diet counseling and exercise programs.

The researchers systematically reviewed randomized trials and observational studies, pooling data on weight trajectories after treatment cessation. They compared GLP-1 users against participants in lifestyle interventions, tracking regain rates over time. Statistical modeling extrapolated longer-term outcomes based on observed patterns during the first 12 months post-treatment.

Key findings showed rapid weight rebound among GLP-1 users. One year after stopping, many had regained nearly all lost weight—far outpacing the slower regain seen in diet-and-exercise groups. Experts like Adam Collins from the University of Surrey suggest prolonged high-dose GLP-1 exposure may suppress natural hormone production, making overeating more likely once medication stops.

While some long-term projections relied on modeling rather than direct observation, the pattern was clear: drugs alone don't sustain results. Muscle loss during treatment—ranging from 15-60% of total weight lost—further complicates matters, especially for older adults.

Researchers emphasize combining GLP-1 therapy with strength training, nutrition counseling, and behavioral support for lasting success.

REFERENCE: West S, Scragg J, Aveyard P, Oke J L, Willis L, Haffner S J P et al. Weight regain after cessation of medication for weight management: systematic review and meta-analysis BMJ 2026; 392 :e085304 doi:10.1136/bmj-2025-085304

Study links Higher consumption of preservatives to increased diabetes type 2 risk

Your daily snack might be silently raising your diabetes risk. A major French study published in Nature Communications reveals that common food preservatives—those E-numbers keeping packaged foods fresh on shelves—significantly increase the chances of developing type 2 diabetes. Researchers from Inserm and other institutions analyzed dietary data from over 108,000 adults and found that higher consumption of these additives linked to a 40-49% elevated risk, even after accounting for diet quality and lifestyle factors.

Food preservatives fall into two main types: non-antioxidants that block microbial growth (like potassium sorbate, E202) and antioxidants that fight oxygen damage (like citric acid, E330). Found in over 20% of processed foods and drinks worldwide, these additives help extend shelf life but may disrupt metabolism. Previous lab studies hinted at cellular damage and blood sugar problems, but human evidence was lacking—until now.

The research team tapped into the NutriNet-Santé cohort, France's largest nutrition study. Between 2009 and 2023, over 100,000 adults regularly reported their eating habits through detailed 24-hour food diaries, including brand names of packaged products. Scientists cross-referenced this with databases like Open Food Facts and EFSA to precisely calculate exposure to 58 preservatives. They tracked medical histories, physical activity, smoking, alcohol use, and nutritional intake to isolate additives' effects.

During 14 years of follow-up, 1,131 participants developed type 2 diabetes. Those eating the most preservatives overall faced 47% higher risk than low consumers. Non-antioxidant preservatives raised risk by 49%, while antioxidants increased it by 40%. Among 17 commonly consumed additives, 12 showed strong links—including widely used ones like sodium nitrite (E250) in processed meats, potassium sorbate (E202) in yogurts and sodas, and citric acid (E330) in countless beverages.

"This is the first large-scale human study linking preservatives to diabetes risk. The findings align with lab evidence of metabolic harm and support calls to rethink additive regulations.The team urges choosing fresh, minimally processed foods—a simple step that could meaningfully lower diabetes risk while regulators reassess safety limits.” said lead researcher Mathilde Touvier.

REFERENCE: Hasenböhler, A., et al. (2026). Associations between preservative food additives and type 2 diabetes incidence in the NutriNet-Santé prospective cohort. Nature Communications. doi: 10.1038/s41467-025-67360-w. https://www.nature.com/articles/s41467-025-67360-w

Research shows high-protein diets offer strong anti-cholera protection

Milk and cheese could be powerful weapons against cholera—one of the world's deadliest bacterial infections. A new study from UC Riverside reveals that high-protein diets, particularly those rich in casein (milk protein) and wheat gluten, can reduce cholera bacteria in the gut by up to 100 times compared to balanced diets. Published in Cell Host & Microbe, the research uncovers how everyday foods might dramatically alter infection outcomes without antibiotics or drugs.

Cholera kills through severe diarrhea caused by Vibrio cholerae bacteria, which uses a needle-like weapon called the type 6 secretion system (T6SS) to inject toxins into gut cells and neighboring bacteria. In regions with poor sanitation, rapid rehydration saves lives, but antibiotics risk creating resistance. Researchers wondered whether diet could influence this deadly battle in the gut microbiome.

Ansel Hsiao's team tested three dietary extremes on infected mice: high-fat, high-simple-carbohydrate, and high-protein diets. They measured cholera colonization levels and tracked bacterial behavior in the gut. High-fat diets showed minimal protection, while carbohydrates offered limited defense. But the high-protein groups—especially casein and wheat gluten—nearly eliminated cholera growth.

Digging deeper, researchers discovered these proteins specifically suppress T6SS, cholera's microscopic syringe. Without this weapon, the bacteria struggle to kill competitors or establish gut dominance.

The mechanism appears tied to amino acids from protein breakdown disrupting bacterial protein machinery. Casein and gluten stood out because their specific amino acid profiles most effectively mute T6SS. This dietary protection lasted throughout infection without side effects.

In cholera-endemic areas of Asia and Africa where clean water remains scarce, this discovery offers hope. High-protein foods are inexpensive, widely available, and carry no resistance risk—unlike antibiotics. Regulatory agencies already recognize casein and gluten as safe, making rapid deployment feasible.

Dietary defense won't breed superbugs. Some proteins clearly outperform others, but improving nutrition universally protects against many infections. This research transforms cholera from solely a sanitation problem into one where strategic eating could save lives.

REFERENCE: Liu, R., et al. (2025). Diet modulates Vibrio cholerae colonization and competitive outcomes with the gut microbiota. Cell Host & Microbe. doi: 10.1016/j.chom.2025.11.004. https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(25)00464-0