Its almost 100% certain - if your vegan diet looks exactly like a standard American diet (using substitutes) - you will gain weight unless you're meticulous about counting calories. If you want to be healthy on a vegan - do not eat vegan junk food. Being healthy on a vegan diet means eating whole foods - minimally processed. The food you eat should be high in fiber, low in fat, and high in water content. Most of your…
Anyway, you will have to eat really shit food to not get enough protein. I live in a country with among the world's highest recommended protein intake (Sweden, 15%E - but anything between 10 and 20 is within recommendations) which I reach without even trying.
The WHO and American lower limits are impossible to come down to unless you live on oil and rice or eat ultrashit food.