Ask HN: How do you track your diet?

HN: I'm on my 4th week of dieting with great results. So far I've been using a spreadsheet to track my food and workouts.

I'm following a low-carb nutrition plan, where instead of counting calories I focus on macronutrients: grams of carbs, protein and fat.

Which apps or methodologies do you use to track your food and/or workouts?