ambiguity: "consume X calories"
con·sume
v. con·sumed, con·sum·ing, con·sumes
v. tr.
1. To take in as food; eat or drink up. See Synonyms at eat.
2. a. To expend; use up: engines that consume less fuel; a project that consumed most of my time and energy.
b. To purchase (goods or services) for direct use or ownership.
In order to lose weight, you need to consume [2a] more calories than you consume [1].