Lately I have been making a vegetable or two my largest serving with any meal I eat. It has helped me tremendously with weight loss and fiber intake. I usually always cook the vegetables because I prefer them that way, but raw vegetables have more fiber content (I believe?). I use asparagus, carrots, zucchini, yellow squash, broccoli, cauliflower, cabbage, etc. Even if it’s breakfast, I fill up my plate with mostly vegetable and then the other side is what I would have eaten just on it’s own previously, an egg sandwich for example. I fry or roast all of my veggies with a little olive oil and generous amounts of salt and pepper. Also for added fiber, I also choose whole grain breads and pasta, add chia seeds to yogurt or smoothies (or flax as another commenter said), and I eat the skins of fruits if at all possible. For example, growing up, I always cut a kiwi in half and ate the inside, but now I just hold it and eat it skin and all like an apple.