Step-by-step explanation:
What you eat affects you because, what you eat, your brain also eats. Conversely, it uses what you eat, to run and stay awake. So when you eat a bunch of sugar, you may become super energetic and then crash (get super tired). This is because your body ingested too much sugar, which surpassed the point of where sugar can actually help you stay awake. Diet can affect you through weight as well. Where your body endures too much or too little of something from your diet and either stores it because it does not receive it enough. Or your mood could be affecting how your body stores food through stress.
So in total, your diet affects you through weight, mood and more! Based on how you're feeling in that moment, and how much your are lacking in nutrients, or how much oversupply you have of certain nutrients.