Short Answer,
No.
No food is “bad” beyond it’s an overall contribution to the diet as a whole and how much of it is consumed. They are a convenient and tasty source of protein which can be handy.
However, I wouldn’t recommend eating More than one a day (which I would personally even consider a high consumption) to the three main issues with overconsumption.
Firstly, they can be hyper-palatable 🤤 to some which may hinder future adherence to a diet because hyper-palatable foods are simply easier to overeat.
Secondly, due to the synthetic fibers, they can result in GI distress/ discomfort if eaten in excess 💨.
My last point and most important is the inaccuracy in the nutrition of these "low carb " bars.
Have a look at the main ingredients:
1) Ismalto-oligosaccharides (IMO’S): a combination of glucose and maltose, which protein companies included in their bars to use as binding agent as they thought it acted as a fiber which could not be digested.
However, studies show that this ingredient is digestible (up to 83%) and raises blood glucose slowly therefore it IS considered a carb (just low GI) rather than fiber.
In 2014, Quest was being sued for misleading nutrition labeling on their bar which understated their calories by 20% and overshot their fiber content by 750% 😳. Lab tests were done on IMO’s to show they did in fact act as a fiber, but these tests never specifically tested the outcome on human blood glucose levels.
2)soluble corn fiber🌽: Soluble corn fiber is another bonding agent. This ingredient is fermented by bacteria in the gut and turned into short-chain fatty acids, which don’t raise blood glucose therefore don’t count as active carbs.
The last popular ingredient is inulin (not insulin). mainly found in fulfill bars is a fiber from plants. It doesn't raise blood glucose so can be considered low carb. Too much can cause gas, bloating, and digestive discomfort.
Protein bars are perfectly okay and quite nice in moderation. But as always a diet should be mainly composed of “wholesome” nutrition-dense foods. Nothing wrong with them every now and then as a snack 😊