calorie

foods with high/low calories高/低热量食品

You should try to eat fewer calories [=eat less food with high calories] and exercise more.你应该尽量少吃高热量食物，多运动。

a low-calorie diet低热量饮食

No dessert for me—I'm watching/counting my calories. [=being careful not to eat too much]我不要甜点——我在控制饮食呢。