- QUOTE: In a way, there’s nothing strange in the fact that we see protein as valuable, because it is. Along with fat and carbohydrate, it is one of the three basic macronutrients, and arguably the most important. We could survive without carbohydrates, but fat and protein are essential. Protein is the only macronutrient to contain nitrogen, without which we cannot grow or reproduce. There are nine amino-acid proteins – the building blocks of human tissue – that we can only get from food. Without them, we could grow neither healthy hair and nails nor strong bones and muscle, and our immune system would be impaired. A child who lacks vital protein in the first five years of life will suffer from stunting and sometimes wasting, too, as the dreadful persistence of malnutrition in the developing world reminds us.