ד״ר זיו אב - מה שלא סיפרו לכם בנוגע לזריקות הרזיה

Short Summary

Main recommendation: Anyone considering weight-loss injections (GLP-1 agonists such as Ozempic, Wegovy, and Mounjaro) should understand that they are a "plaster" that suppresses hunger rather than fixing the underlying metabolic problem, so people using them must protect muscle mass through adequate protein intake and resistance training, and they should be used most clearly by people with severe obesity and a history of heart attack, stroke, or active heart disease. The speaker, Dr. Ziv Av, presents these points as his reading of the science, not as professional medical advice.

Key Points

• The drugs mimic a natural hormone that slows stomach emptying, strengthens the brain's fullness signal, and triggers insulin release in response to food; their original purpose was diabetes treatment.
• Their effect lasts about a week, compared with roughly two minutes for the body's natural hormone.
• According to the speaker, a British Medical Journal study shows people regain weight faster after stopping than after a regular diet, and about two-thirds of lost weight returns within the first year after stopping.
• Around 50% of users stop within a year and about 70% within two years, due to digestive side effects, fatigue, low motivation, and cost.
• The speaker cites a study in which a 20 kg loss in a 65-year-old woman could include about 8 kg of muscle and bone.
• The drugs may reduce dopamine-driven reward responses, which the speaker links to lower interest in food, addictive substances (like alcohol and cigarettes) and other pleasures, though he says the evidence on depression is unclear.

Details Worth Noting

• Concrete instructions: Protect muscle while using these drugs by (1) eating adequate protein and (2) doing resistance (strength) training. The speaker says that without both, there is a substantial chance that within two to three years a person will be in a worse condition than when they started. He notes that these two habits can conflict with the drugs' appetite suppression and motivation effects, and he suggests most prescription recipients are not given this explanation.
• The speaker recommends the drugs absolutely for people with severe obesity and prior heart attack, stroke, or active heart disease, citing a study showing about a 20% reduction in the chance of another cardiac event or stroke.
• He says a Mediterranean diet has been shown in another study to reduce the chance of a second event by 50–70%, though he gives no further detail on that study.
• For people who only want to lose a few kilograms, he suggests exhausting other approaches first, while stating that healthy weight is an important goal.
• He notes that muscle loss contributes to regain, since muscle is the tissue that burns the most energy.

Bottom Line

Weight-loss injections can be powerful and even life-saving for people with serious metabolic disease and heart history, but for others they risk muscle loss, rapid regain after stopping, and side effects, so muscle protection through protein and strength training is essential for anyone who uses them.