You could eat a mcdonalds once a week without worry of health deterioration.
There was a program about this, the person stayed on different diets, or people. One was eating mcdonalds only & after the month their lack of steam, their drive & motivation was compensated, they had put on weight, this is fat not muscle, & their heart and blood pressure and rates had changed, not huge amounts, but this was only one month. Several years & I would imagine you would change your life line by many years
