Yeah beans are generally considered off limits and I would look to get protein from animals instead. That being said, some people do utilize beans, though for carbs not for protein, at certain times, specific to training. The gluten in the beans is a warning to celiacs (people that have strong allergic reaction to gluten) and probably means these beans were processed in a factory that also processes gluten-containing products. Your beans most likely don't contain a large enough amount of gluten, and given that you're French and have presumably eaten plenty of breads in your life, you would already know if you're seriously gluten intolerant. You're not.
Focus on meat and vegetables, do some weight training (2x/week is enough) and you'll drop body fat in no time.