Thomas Rozdzynski eating foods that you can pronounce what's in it is my biggest suggestion.
There is so much more to expand upon, but the above will help with getting you on the right path.
Also do be afraid to do your own experiments. Sometimes too aging will play a role. You might have been able to eat something pre-training 10 years ago that doesn't work now. If you can't figure it out, find yourself a professional to help cut down on wasted time.
Commented on Weekly QuestionWhen you want to learn...
17 Mar 07:58
When searching out new techniques now I turn to BJJ Fanatics and YouTube the most. The hardest part can be figuring out with YouTube or Instagram if the instructors are showing legitimate techniques or flashy IG techniques that really only work if your partner is 100% compliant.
For someone newer to jiu jitsu RolTV is a great source. However if you are looking for something not yet on there or maybe an instructor that fits your body type, asking your instructors is a great option. If you don't want to do that, seeking out someone who has been around for awhile and is maybe posting as an academy owner or instructor or who has proven techniques through competition are great bench marks of who to watch.
Or asking an instructor on here for suggestion too!