The Montignac diet is a weight-loss diet that was popular in the 1990s, mainly in Europe. It was invented by Frenchman Michel Montignac (1944–2010), an international executive for the pharmaceutical industry, who, like his father, was overweight in his youth. His method is aimed at people wishing to lose weight efficiently and lastingly, reduce risks of heart failure, and prevent diabetes.
Carbohydrate-rich foods are classified according to glycemic index (GI), a ranking system for carbohydrates based on their effect on blood glucose levels after meals. High-GI carbohydrates are considered “bad” (with the exception of those foodstuffs like carrots that, even though they have high GIs, have a quite low carbohydrate content and should not significantly affect blood sugar levels).