I lift weights. Not too big on cardio, after many attempts at doing it (running, cycling, swimming). Lifting weights is the one thing that I finally found I can stick with. My diet is decent, mostly cook for myself and avoid highly processed foods and a lot of sugar. I am not strictly following any dietary program though.
I like the effect the weightlifting has on my body. It's nice that I have some definition and strength. But honestly cannot say it's had a big effect on my energy, motivation, outlook, etc.
I have tried enough things that other people say have made a tremendous difference in their life, from exercise to supplements to diet to reading philosophical books and they just... don't. I still feel like the same person. I don't think there are any secret tricks. People are who they are, fundamentally. Accepting that feels like giving up sometimes, but also brings some peace and freedom.