The bone health effects can be permanent. Peak bone mass in females is achieved by the ages of 26-30, so if you suffer from energy deficiency that's not recognized during your adolescent and collegiate years, then your ability to reach your peak bone mass is going to be compromised. It can be difficult to correct this, and it can potentially cause osteoporosis later in life. RED-S can also cause short-term reversible effects, such as a slow heart rate, bloating, irritability, depression, difficulty concentrating and a compromised immune system.