Medical Bulletin 09/March/2026 - Video

Here are the top medical news for today:

Scientists Explain Why We Still Crave Food After Feeling Full

The global obesity epidemic has become a major public health concern, prompting researchers to investigate the behavioral and biological factors that contribute to overeating. One important factor is eating in the absence of hunger. This behavior may reflect a breakdown in normal appetite regulation, particularly in environments where people are constantly exposed to food-related.

A recent study published in the journal Appetite examined how learned responses to these food cues may encourage people to eat even when they are not hungry.

Normally, food cues activate reward-related responses in the brain that motivate eating. However, once a person becomes full, the motivational value of food typically decreases, and the desire to eat declines. When this reduction does not occur, researchers describe it as devaluation insensitivity, meaning the brain continues to treat food as rewarding despite satiety.

Eating behavior is influenced by many factors, including hunger, energy needs, the taste and appeal of food, past eating experiences, cultural habits, and the effort required to obtain food. Physiological signals also play a role.

The hormone ghrelin increases when blood sugar levels fall, stimulating hunger and encouraging food intake. In contrast, hormones such as leptin signal satiety and normally reduce the brain’s response to food-related stimuli.

To investigate how food cues influence behavior, researchers conducted an experiment using electroencephalography (EEG) to measure brain activity in response to food images. The study involved 90 university students who completed a learning task where images of certain foods were linked to rewards. Midway through the experiment, participants were fed one of the foods until they felt full, effectively reducing its value.

Interestingly, while participants reported reduced desire for the food and chose it less often afterward, their brain signals still showed strong reward responses when they saw images of it. This suggests that learned neural responses to food cues may persist even after satiety, potentially encouraging habitual overeating in modern food-rich environments.

REFERENCE: Sambrook, T. D., Wills, A. J., Hardwick, B., et al. (2026). Devaluation insensitivity of event related potentials associated with food cues. Appetite. DOI: https://doi.org/10.1016/j.appet.2025.108390. https://www.sciencedirect.com/science/article/pii/S0195666325005434

Study Finds Dietary Fat Ratios Shape Immune Cell Function

New research has shown that the types of fats people consume in their diet can directly influence the strength and survival of the body’s immune cells. Scientists from the University of Queensland, working with international collaborators, discovered that dietary fats can alter the internal fat composition of T cells, which are critical immune cells responsible for protecting the body against infections and cancer. Their findings, published in the journal Nature, reveal an important connection between diet and immune system performance.

The research team found that diets with a lower ratio of polyunsaturated fatty acids (PUFAs) to monounsaturated fatty acids (MUFAs) help make T cells more resilient and less likely to die prematurely. This discovery provides new insight into how everyday dietary choices may influence immune function.

T cells play a vital role in coordinating the immune response. They help identify harmful pathogens, support the production of antibodies, and attack infected or cancerous cells. According to the researchers, the fats consumed in food can change the lipid composition inside these immune cells. These changes can either strengthen the cells or make them more vulnerable.

Foods rich in PUFAs include fatty fish and soybeans, while MUFAs are commonly found in foods such as olive oil and avocados. The study suggests that a higher presence of MUFAs relative to PUFAs may protect T cells from a specific type of cell death caused by oxidised fats damaging the cell membrane.

This protection is especially important for follicular helper T cells, which assist the body in producing antibodies. Stronger and more stable T cells may therefore improve the body’s response to vaccines. In addition, resilient T cells are better able to multiply and attack tumours, potentially improving the effectiveness of cancer treatments.

Although researchers have not yet identified the ideal balance of these dietary fats, the findings suggest that adjusting dietary fat intake and targeting lipid metabolism could become a simple strategy to strengthen immunity and enhance medical therapies in the future.

REFERENCE: Wang, N., et al. (2026). Lipid metabolism drives dietary effects on T cell ferroptosis and immunity. Nature. DOI: 10.1038/s41586-026-10193-4. https://www.nature.com/articles/s41586-026-10193-4

Seven Hours of Sleep Linked to Lower Insulin Resistance Risk

A large observational study suggests that sleeping about 7 hours and 18 minutes per night may be the optimal duration for reducing the risk of insulin resistance, a condition that often precedes Type 2 Diabetes. The research, published in the journal BMJ Open Diabetes Research & Care, also found that excessive weekend “catch-up sleep” may negatively affect glucose metabolism in some individuals.

Researchers analyzed data from 23,475 adults aged 20 to 80 who participated in the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2023. Among them, 10,817 participants had additional information about their weekend sleep patterns. The team evaluated sleep duration and its relationship with insulin resistance using a measurement called the estimated glucose disposal rate. Lower eGDR values indicate greater insulin resistance, while higher values suggest healthier glucose metabolism.

On average, participants slept 7 hours and 30 minutes on weekdays and about 8 hours on weekends. Nearly 48% reported catching up on sleep during weekends. When researchers analyzed the data, they discovered an inverted U-shaped relationship between sleep duration and metabolic health. The highest eGDR—indicating the lowest risk of insulin resistance—occurred at around 7 hours and 18 minutes of sleep per night.

For people who slept less than this optimal amount on weekdays, getting 1–2 hours of additional sleep on weekends was linked to better metabolic outcomes and higher eGDR. However, for individuals who already slept more than the optimal amount during the week, adding more than 2 hours of weekend catch-up sleep was associated with lower eGDR, meaning a higher risk of insulin resistance. This effect appeared particularly strong among women and adults aged 40 to 59.

Researchers note that sleep and metabolism influence each other. Poor glucose regulation can disrupt sleep patterns, while abnormal sleep durations may further worsen metabolic health. Although the study cannot prove cause and effect, the findings suggest that maintaining consistent sleep patterns close to seven hours per night may help support healthy metabolism and reduce diabetes risk.

REFERENCE: Fan, Z., et al. (2026) Association of weekday sleep duration and estimated glucose disposal rate: the role of weekend catch-up sleep. BMJ Open Diabetes Research & Care. DOI: 10.1136/bmjdrc-2025-005692. https://drc.bmj.com/content/14/2/e005692