Cain I gain weight on this diet???

Im a 18yo male with an autoimmune condition called ankylosing spondylitis which causes joint pain and has made me lose a ton of weight (170cm, 55kg before diagnosis and now I weigh 45kg). Ive heard many success stories from people with autoimmune diseases on this diet and I want to try it but I cant afford to lose anymore weight. Should I give this a shot or just go do keto or paleo or something?

from Zero Carb Zebras http://bit.ly/2Sihon3
via IFTTT