How can I use less ram? Texture and model loading - c++

Question

So I am following the opengl tutorial at https://learnopengl.com/Model-Loading/Model and when I run the application it is using a little more than half a gigabyte for textures and models! But when I check the size on disk of all the textures and the model file its only ~30MB on disk?
How can I make it so I use less ram? I think the issue has something to do with loading the texture or the model, but I'm not sure why it is using so much ram. This is the texture loading function:
unsigned int TextureFromFile(const char* path, const std::string& directory, bool gamma)
{
std::string filename = std::string(path);
filename = directory + '/' + filename;
unsigned int textureID;
glGenTextures(1, &textureID);
int width, height, nrComponents;
unsigned char* data = stbi_load(filename.c_str(), &width, &height, &nrComponents, 0);
if (data)
{
GLenum format;
if (nrComponents == 1)
format = GL_RED;
else if (nrComponents == 3)
format = GL_RGB;
else if (nrComponents == 4)
format = GL_RGBA;
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D, textureID);
glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
stbi_image_free(data);
}
else
{
std::cout << "Texture failed to load at path: " << path << std::endl;
stbi_image_free(data);
}
return textureID;
}
The tutorial's source code can be found here.