Nutrition during the marathon run

Don't trust foreign nutrition. Better to have trusted food you tested before on your training runs. Which might be good for a marathon run?

Isotonic drink

Smoothies

Energy gel

Nuts

100g dried fruits contain:
Banana: 100 mg magnesium
Fig: 70 mg magnesium
apricot: 50 mg magnesium
date: 50 mg magnesium

See also:
Nutrition for runners - infographic | BBC Good Food
Schneller rennen mit der richtigen Ernährung | rbb Rundfunk Berlin-Brandenburg