If you have noticed stubborn weight gain, lower energy, or changes in strength, you may be wondering whether hormones could be part of the reason. Many men ask can low testosterone cause weight gain in men when healthy habits no longer seem to work the same way. That question matters because testosterone plays an important role in muscle mass, metabolism, and body composition. In this guide, you will learn how hormone changes may influence weight, what warning signs to watch for, and when it may be time to seek professional guidance. You may also notice other common warning signs of low testosterone beyond changes on the scale.