As if any further proof were needed that dieting is bad for you.

Motorists have been warned from taking to the wheel while on a radical diet because body reaction times are significantly reduced, according to the Austrian automobile association (OeAMTC). Significantly lower calorie levels cause headaches, eyesight problems and dizziness and in serious cases even a circulatory collapse, the association says. Motorists were warned to especially watch their blood sugar levels when undergoing a zero diet because body reaction times were significantly slower.