Many Catholics ( including myself) are unhealthy.  Now is the time to get healthy and stop relying on quacks. 

These diets like Vegan, Keto etc don’t work. 
Think back when plates were smaller and families thanked God for their food and ate at home.  

I don't know, Keto has been great for me. I wouldn't want to do it for the rest of my life, but it has helped me be conscious of what I'm eating and how that affects my quality of life and in turn my family's life. 
After 3 kids very close together and then a really ugly miscarriage, my muscles were shot and my body was deficient in minerals. I was tired, weak, and hanging on by a thread emotionally. It took me a long time to even get up the energy to take short walks. Keto helped me get my energy back so that I can exercise more and be more active in general. I'm not climbing 14,000 ft mountains again, but I can at least be active with the kids and enjoy brisk walks again!