So, what do we know about how weight loss medications affect our relationship with food?
Reduced Hunger
Glucagon-like peptide-1 (GLP-1) receptor agonists such as semaglutide (Wegovy) and tirzepatide (Mounjaro) have been proven to help people with obesity lose weight. By mimicking the action of the GLP-1 hormone, they reduce appetite and feelings of hunger and increase the feeling of fullness.
“Its mechanism of action makes a person feel fuller—and also regulates a hormone from the pancreas to stop the liver from releasing more sugar,” says Dr. Simon Dryden, Head of Biosciences at London Metropolitan University. “It also increases the amount of insulin a person produces, which helps reduce blood sugar in people with type 2 diabetes and allows more carbohydrate to enter body organs.”
Studies have also shown that these medications reduce the desire to consume alcohol.
Unhealthy Foods Become Less Appealing – At Least Temporarily
GLP-1 receptor agonists reduce the allure of fatty, sugary, and salty foods. This, combined with reduced appetite, leads to many patients losing their desire for such products.
This effect is closely linked to the neurophysiological effects observed after bariatric surgery. In the period following bariatric surgery, the level of naturally produced (endogenous) GLP-1 in the gut significantly increases (by about fivefold). This hormone acts on the regions of the brain that determine the hedonic (reward) value of food. GLP-1 reduces the attractiveness of food, especially high-fat and high-sugar products.
The changes induced by GLP-1 medications mirror the results of bariatric surgery in terms of food preferences:
- Change in Taste Preferences: Approximately 20% of bariatric patients experience a long-term shift in their relationship with and preference for certain foods.
- Temporary Changes: A much larger percentage of patients experience these changes in the immediate months after surgery, before food preferences and taste perception gradually return to baseline.
The experience with GLP-1 medications essentially reflects the processes caused by endogenous hormonal changes following bariatric surgery.
Altered Taste Perception
Recent scientific studies suggest that GLP-1 receptor agonists have a direct impact on taste buds and the regions of the brain involved in taste processing.
It has been observed that for a certain percentage of patients undergoing treatment with GLP-1 agonists, food becomes saltier or sweeter, although the perception of bitterness and sourness does not change significantly.
This phenomenon is due to these substances acting not only on the central nervous system (brain) and the gastrointestinal tract but also influencing taste cells and neural pathways.
Notably, patients who reported this change in taste (increased sweetness or saltiness) were twice as likely to report a feeling of satiety and had a significantly reduced appetite for food. This points to the potential role of altered taste perception in the mechanisms of weight loss.
Everything May Taste Saltier or Sweeter
These drugs also seem to change how food tastes. According to new research, about one-fifth of patients taking Ozempic, Wegovy, or Mounjaro say that food tastes saltier or sweeter compared to before, but the perception of bitterness or sourness remains unchanged.
Participants who reported that food was saltier or sweeter were twice as likely to feel full compared to those whose perception of saltiness or sweetness did not change. Those for whom food tasted sweeter were 67% more likely to report a reduction in appetite and 85% more likely to report a reduction in cravings compared to those whose perception of sweetness remained unchanged.
Increased Gastric Irritation May Occur
Tastes may change because the weight loss medications can cause an unpleasant feeling if a person eats unhealthy foods. Gastrointestinal side effects like nausea, bloating, diarrhea, and constipation are more common side effects of GLP-1s. These effects can be exacerbated by acidic, spicy, or fatty foods and drinks.
“When people start eating high-energy food while on these medications, they feel unwell,” scientists say. “So it’s not just that these hormones reduce the pleasure of these foods, but also that some people have what we call post-ingestion side effects. Therefore, they might avoid [unhealthy foods] simply because it makes them feel bad.”
