Most physicians will agree that what you eat does impact your emotional state. Give kids a high sugar snack and we all know what happens. Adults are no different. The impact may be subtle or dramatic, but your last meal is contributing to how you are feeling at this moment.
Being aware of what impacts you individually with your unique brain chemistry is a first step in then choosing the foods that are right for you.
Also consider taking a food sensitivity test: a simple serum based exam and you can see for yourself what foods are causing an immune response that you should reduce or avoid. Ultimately, living and feeling your best is our goal.