i raised my first son without any animal meat or gluten for his first year and maybe once a week to once a month for his second year....for protein i did serve eggs....
but also he ate almost every day lentil/vegetable soup pureed or bean/vegetable soup pureed. we also served a lot of sweet potatoes and buckwheat, both of which are very high in micronutrients. and organic, whole fat yoghurt, avocado.... buckwheat and millet make nice porridges when blended with a hand-blender, with butter or olive oil and a pinch of salt (and fruit is possible too). at age one i started blending almonds and walnuts into some foods, too. and added flax oil. and quinoa. (tried this when he was younger but it was coming out undigested no matter how well i cooked it. but you can try with a hand blender). and glutenous whole grains.
with my second son, i had read some other points of view and decided to start serving organic meats from 6 or 7 months sometimes, always mixed with vegetables in a puree soup. and mackerel in olive oil. in addition to the eggs, buckwheat, millet, full fat organic yoghurt....lots of veggies and healthy fats. (egg yellows only until 12 mos).
so this is not scientific at all, but my second son gained weight much easier and developed much quicker. it could be just a genetic thing or a coincidence.
the website of dr weston price has some very strong opinions (and some research) about this that are interesting to add into any discussion in either direction.