Kshema is retaining or protecting what you have acquired. Retention of what is desirable and what you want. Retaining the extra weight that you have gained is not Kshema.
Yoga and Kshema appear together in a compound, so the meaning for yoga is acquiring what you do not have. And it must also be desirable to you.
Look at normal life of any person. All his concerns can come under one of these two. What is it that bothers him? Just think of any one thing. It will either be about something he wants, yoga or something he is afraid to lose, Kshema. He has no peace; he wants to gain it—yoga. He does not have enough money; he wants to gain some —yoga. He is losing his hair, his health; he wants to retain them —Kshema. Yoga and kshema indicate a lot about the life of a person. If yoga-kshema is taken care of, everything is taken care of.
The Lord says, 'I take care of these for those who are always non‑separate from Me—nitya-abhiyuktanam yoga-kshemam vahami aham.' He always think -chintayantah mam - inquire into Ishwara and also seek Ishwara - paryupasate. His object of prayer is to find Ishwara alone. He says, 'So I pray to know where you are, what you are.' After finding Ishwara what does he want? He says, 'Nothing; only to know that I am one with You.' The object of his prayer, the pursuit is only Parameshwara. He does not use Ishwara for gaining limited ends. He only seeks to know him. he is not anxious about looking after himself; nor is he afraid of what will happen to him. He is with Ishwara and non‑separate from Him and has no concern for his own Yogakshema. Whatever happens, happens. Everything, even the desires, are all in the hands of Ishwara. Since he recognises the law of karma as non‑separate from Ishwara, whatever takes place is Ishwara for him. He does not use Him to protect his Yogakshema but Yogakshema is taken care of by Lord himself in the form of the laws of karma. So he has no concern about his Yogakshema.
This attitude is what will make one steadfast in Aparigraha. When God in the form of Organisation, in the form of Society takes care, thinking and working for the Organisation, Society is the only objective and that is what is to be done. One therefore, need not possess anything. He is looked after by Organisation, the Society.