What is the most likely cause of protein and ketones in urine, egfr of 78%, negative cultures and normal blood results.

How much?: Miss a meal and you'll have +1 ketones in your urine. Many people have trace proteinuria and this is okay. You may also have orthostatic proteinuria caused by standing up -- some people are like this -- and this is easily ruled in or out by checking your first-voided urine in the morning. Forget "most likely"; you do need to have the cause found. Best wishes.