I can attest to that. My breakfast is a cup of coffee or two. If I do my exercise during lunch, a casual 2-3 miles walk, then I can get away with having a glass of juice or small snack for lunch. I am more alert in the afternoon and more productive.
Not sure how things work, but I tend to crave for food more if I don’t skip my walk. And if I eat a full meal for lunch, my afternoon is pretty much shot especially around 2-3 p.m.
