I have been in this business for seven years and have studied this subject extensively.
I have come to the conclusion that most addictoins are manifested by one’s past trauma and experienceds in life. Most people with eating disorders are seeking inner peace. They are trying to fill a void within. It is not that they are lazy, or don’t care. IF they did not care, they would not be seeking help.
Eating disorders are very complicated, and not resolved by most standard approaches such as diets and exercise. This may help, but if there is truely a eating disorder that is in place, the client needs professional help..couselling, which is not in the scope of personal trainers.
I have worked with many clients who have had eating disorders and I found my successes were with those who were exercising, eating healthy balanced meals (no diets) and getting counseling.
I have had gastric by pass clients who gained all their weight back even when they were following my program, because they refused to go to their schedule counseling sessions.
Stress is the number one factor for triggering addictions, as well as low self esteem.
Consider how much stress your client is under. Maybe a divorce, or highly stressful job, or even you are working with someone who is a perfectionists and puts too much stress on themselves. Suggest ways to reduce stress such as medition, yoga, or mind body biofeed back sessions with a professional.
Be aware that obesity is a disease not to be taken lightly.
But also be aware that IF someone does not lose weight under your guidance, you have done everything you can do help them. You are not a failure, and neither are they. They just may need professional help.