fat isn't unhealthy, it's just calorie dense. The only issue i see with eating 3 burgers per day is that you should be eating a varied diet to make sure you don't get too little or too much of any one nutrient or potential toxin. Plus burgers have too much meat compared to the amount of greens..

and honestly 3 burgers per day is a completely normal amount of food, too little if anything. Even with fries that's about as much as most people would eat in a day.

but really "eating healthy" is basically just a matter of not eating a significant amount of sugar and getting as much greens as possible, making sure 90% of what you consume is home-made (even if that includes quite a lot of pastries) is pretty fool-proof. Just make your own burgers and add some more lettuce.