Protein is one of the most important nutrients for the human body. The human body can use proteins for energy but it cannot use carbs to make protein. For both carbs and protein, the body can use them equally for energy but it prioritizes carbs for energy first. In simple words, our bodies can use both protein and carbs for energy but they cannot produce proteins on their own. It needs to take protein from the food we eat and the daily protein requirement can vary depending on what you eat and what kind of lifestyle you have.
One important thing to understand about our daily protein needs is that the human body does not discriminate between protein sourced from plants or meats and animal products. All protein is equally beneficial but plants usually contain less of it. Vegetables and legumes in general contain some protein. Fruits are the worst option for protein.
Also, the highest quantities of protein you will find in seeds and nuts. However, the most reliable source of protein is animal products. Alternatively, you can supplement your daily protein intake using protein supplements in the form of a powder that can also be vegan or can be made from whey.
Looking at more specific numbers, everyone needs protein in their diet and the requirements can vary. A healthy adult with a sedentary lifestyle has a daily protein requirement of around 0.5 to 0.8 grams of protein per pound of body weight. Things change a bit for active adults that focus on growing their muscle mass.
The daily protein requirement recommended for muscle growth is a minimum of 1 gram of protein per pound of body weight. This daily protein requirement can increase depending on how hard you train, how often, and how much muscle mass you already have. It can be as high as 2 grams per pound of body weight but these specific numbers should always be checked with a professional.