Can protein bars make you gain weight?

Why would protein bars make you gain weight? There are two reasons.

Many protein bars get their protein from soy

Soy can change estrogen metabolism and in higher doses or consumed frequently (as in this patient), can help to raise estrogen levels.  Estrogen is a anabolic steroid and tends to make us soft and round like a pregnant women.  

Protein bars oftentimes contain artificial sweeteners

The second reason has to do with sugar metabolism.  Protein bars that don’t have added sweeteners tend to not taste very good so the manufacturers will either sweeten them with sugars or artificial sweeteners.  The added calories from the sweeteners of course will be a problem but many people don’t realize that artificial sweeteners can have the same effect.  Artificial sweeteners  will cause insulin resistance eventually sending all of the carbs that we eat directly to storage (fat cells).

Bottom line, avoid those protein bars unless it is an emergency!