Caffeinate your system often. People recognize Mary Kate Olsen as much for her ubiquitous Grande Starbucks cups as for her gigantic, insect-like sunglasses and Balenciaga handbags. In small amounts, caffeine speeds up your metabolism works as a mild, temporary appetite suppressant.
Smoke a lot of Marlboro cigarettes. Mary Kate Olsen smokes Marlboro Red cigarettes as often as she downs Starbucks coffee. Sure, cigarettes, like caffeine, have appetite suppressant qualities, but the effects on your lungs and skin are far more detrimental than a few extra pounds. Most fashion insiders would classify cigarettes as a huge fashion "don't."
Walk everywhere you can. Though Mary Kate Olsen and her sister Ashley can more than afford all the limousine service they want, they often hoof it through the streets of New York, where they have a home. Celebrity trainers agree that walking is one of the best low-impact exercises for healthy weight maintenance.
Eat high-protein foods and cut back on carbohydrates. Mary Kate Olsen underwent treatment for an eating disorder, anorexia, and she learned better ways to maintain her slim figure than starving herself. Sources close to Mary Kate report that she now eats a healthy diet high in protein and low in carbs. Sushi is a particular favorite food of both Olsen sisters, and it's highly recommended by most stars' trainers.