Yes, you can lose weight by eating peanut butter while on a balanced and healthy diet. BUT it all depends on how much PB you consume as it is high in calories and fats. So be careful of your serving sizes.   If on a diet, I recommend eating 100% natural peanut butter as it doesn’t contain added sugars and oils. Reasonable amounts of high-quality peanut butter help with your diet.  Besides, peanut butter satiates you for longer, thanks to its high protein and healthy fat content. You can also safely use it to replace your favorite unhealthy treats without worrying about blood sugar fluctuations.