Android view layout_width - how to change programmatically?

I believe your question is to change only width of view dynamically, whereas above methods will change layout properties completely to new one, so I suggest to getLayoutParams() from view first, then set width on layoutParams, and finally set layoutParams to the view, so following below steps to do the same.

View view = findViewById(R.id.nutrition_bar_filled);
LayoutParams layoutParams = view.getLayoutParams();
layoutParams.width = newWidth;
view.setLayoutParams(layoutParams);

You can set height and width like this also:

viewinstance.setLayoutParams(new LayoutParams(width, height));

Or simply:

view.getLayoutParams().width = 400;
view.requestLayout();