I would have a chat with him and ask how things are going in the spirit of supporting him and helping to explore things a little. You can let him know that from what you have heard/read/experienced, feeling nauseous often happens to people on chemotherapy, and that it would be a good idea to have a chat with his Nurse Specialist. This is because often they can help him to try out different anti-sickness medications and he may have more success with these. You can offer to sit with him as he makes the phone call or to do it for him if he is very fatigued.

Chemotherapy can also change the way foods taste and cause a sore mouth. We'd all be put off eating if food tasted weird and it hurt! The Nurse Specialist might have ideas about how to make sure that the food he can manage is full of calories and nutrients to keep his weight up. There is also a "magic mouthwash" he can be provided with to help mouth sores to heal if this is a problem. His mood may be very low at the moment and that is also something his Nurse Specialist could help with. She may have advice on how to pace activities during the day, what times of the day it would be a good idea to try to eat, how frequently, and the types of food. There may be times when sleeping lots is going to happen, but there may be other times when there are other activities that he would like to do during the day and he might like to have a list of things on paper and access to anything he needs at hand.

You are being a fantastic friend and although he may find it difficult to accept help (for a variety of reasons, perhaps including prior life experiences/upbringing/relationships) the fact that you are taking the time to post here and to seek out ideas on how to help is a very kind thing to do. Good luck with speaking with your friend.

It is very worrying to see a friend with a cancer diagnosis losing weight and pulling back from others. How might it be to gently let him know that you will be there to the best of your abilities? If he has other friends/family you could chat with them about how they might be able to help out with cooking/checking in on him and how things are going/if he is attending appointments.

It might be that at first he pushes you and others away and this might feel very sad and frustrating, but in time he might be more open to offers of help and support. If you are very concerned that he is feeling very low and without motivation to look after himself it would be worth suggesting he let his Nurse Specialist know about this because there are Clinical Psychologists/Counsellors based within cancer teams who can help. They are impartial and have seen many people over the years who might need some additional support/ideas on how to face being diagnosed and treated for cancer. It is understandable that it can be a very overwhelming time for many people. Has your friend experienced low mood or worries in the past? Sometimes ill health can re-trigger dark thoughts. A Psychologist in the team would be an excellent person to speak with in that instance and they can help with gaining an understanding of how to try to plan ahead with pacing activities during the day and help him to understand what some triggers for low mood are and what gets in the way of helping himself to feel better given the circumstances. If your friend gives you permission, as I suggested you can mention to his Nurse Specialist your worries... they won't be permitted to discuss with you his condition unless he gives permission, but it could help them to support him better.

Do you have anyone that you can speak to about your concerns? If can be very hard on friends and family. We care so much and can feel so powerless at times. I hope that you are finding times to care for your needs as this will help you to be there for your friend when he does feel able to accept help.