Losing weight may not be just about what you eatwhen you eat it according to a new study

问题补充：

Losing weight may not be just about what you eatwhen you eat it, according to a new study．

A. so

B. and

C. but

D. for

答案：

A. so

B. and

(答案→)C. but

D. for

解析：句意：根据一份新的报告表明，减肥可能不是你吃什么，而是你什么时候吃。not…but不是而是，固定句型，故选C