Why do the seeds of the sunflower plant have different fat/carb amounts than the plant when it grows?

Sunflower seeds are a tasty snack, packed with healthy fats and nutrients. ... from the plant's large flower heads, which can measure more than 12 ... One type is grown for the seeds you eat, while the other — which is ... Carbs, 6.5 grams ... and other seeds at least five times a week had 32% lower levels

Explanation:

one would be wind another would be water density