You know, I tried for over a year not very successfully, until recently. I started working at a labor intensive job and I eat fruit all day long for fuel, plus a big green smoothie. I wake up very early and usually just have a green juice for breakfast and nothing more until my first break 5 hours later. Then when I get home in the evening I have a big supper of a salad with avocado and sprouted buckwheat. I didn’t intend to but I’ve been gaining quite a bit of weight. And I’m sure a lot of it is muscle as I’m getting much stronger.
Hope this helps.