Whatever you do - don't spend any significant money on any potions or products.
Anyone telling you that any specific regimen, treatment or diet definately makes a perceptable difference is probably lying or deluded.
Due to the nature of ALS - it's virtually impossible to tell if any given treatment is making a difference - any perceived improvement may simply be the natural course of the disease which has its up and downs - if an improvement is due to some diet change - who knows if it was due to something you did yesterday or a year ago - no one can say for sure - outside of a controlled test environment (and even then it would be tough) it's impossible to say.
Having said this - from a general health point of view it makes sense to focus on diet - will it have an impact on your ALS? Who knows - but there are enough related health benefits to justify making a conscious effort to eat healthier - but don't go bananas.
Shortly after I was diagnosed I was very strict about my diet - was afraid to go out - stressed about eating. Now - I still watch what I eat - but I want to live a bit too. So I'm treating myself more often. If I'm going to have a feeding tube stuck in me I want my memory of food to be of something I enjoy - not dry organic granola and raw vegetables - I'll save that stuff for the feeding tube.
Take your dad to the beach. ASAP.
My favourite line from Shawshank Remption:
"Get busy living or get busy dying."
