As for exercise, the Sirtfood Diet book says eating sirtfoods isn't ... So you will lose weight on any diet that only allows 1,000 calories a day — but that doesn't mean it's safe or healthy ...

The result was Woman’s Own publishing a 1,000-calorie-a-day diet in 1966, she says. Diets involving calorie restriction remain among the most popular today. They include the 5:2 diet – created ...