That is some really good tips and well worth trying and will work wonders for some but for those who keep failing or starting and stopping or they just can't seem to drop the weight it maybe worth trying some therapy.
Its surprising why some people can't lose weight, this can be due to self sabotaging behaviors or depression and a range of other reasons, food can become an addiction based relationship and an emotional trap, you eat to feel good and after you have eaten you feel guilty so you eat to feel good again, and so it goes on

If you try and push people to lose weight to fast it can make it even worse, so always encourage and don't push or it can lead to more serious psychological problems.