Overdoing it with certain nutritious foods could be dangerous.
The increased acid intake associated with eating too many oranges or tomatoes can cause reflux.
Tuna is higher in mercury than many other fish, So not to many cans per week!
To much water can cause the sodium in your body to become diluted that can cause impaired brain function. So is your urine looks like water you need to decrease your consumption.
To much soy can cause iron deficiency anemia. Also because soy contains estrogen-like compounds (isoflavones), long-term consumption of large amounts has the potential to cause endometrial hyperplasia, a proliferation of the uterine lining that can lead to uterine cancer.
To much Spinach can cause kidney stones. It's high in oxalate that can cause the stones.
Brazil Nuts contain selenium and to much can cause hair loss.
Animal proteins can be dangerous since it makes your body produce the hormone insulin-like growth factor 1 (IGF-1), which promotes aging and increases your risk of cancer (particularly breast cancer) when present in high levels. In fact, a study published in the journal Cell Metabolism found that there was a four-fold increase in cancer-related death risks and a 75% increase in overall mortality in people who got at least 20% of their calories from lean animal protein (as opposed to 15% or less).
If you recognize that eating a little too much healthy food continues to build up your fat reserves without limit, then yes it is bad. There's needs to be balance, and an awareness of when you've been eating too much (if only through your belt and pants feeling tighter), so that you know you must cut back.
That little too much food adds up over months, years and decades, and that's typically how most overweight people got started (a little at a time, but I think once they noticed they had become overweight the process accelerated due to nervous tension).