Hi, Good luck to your father. The most impotant thing is to keep positvie thoughs and try not to dread the treatments. Rember what ever the side effects, it is eating the cancer cells. However,in this day and age there are new drugs that prevent or lessen most side effects. Honestly, I was only sick1 day in my year of treatments. That was because I forgot to take 1 pill. I took three pills (1 day before treatment, 1 day of treatment, and one after) I do not know what kind of Chemo your Dad is having and maybe these pills will not work for him. Ask your Dr.
I don't know about gaining weight necessarily, but certaily keep a good healthy one and of course if you have lost weight then eat the foods that are necessary for weight gain, All the good stuff we dieters must NOT eat.
Your Dad will find when he goes for treatment that he will be surrounded by people, all ages, who are in the same boat as he and the staff at the Cancers facilities are WONDERFUL in every way. My very best and loving thoughts.... Carol H.
I