To ascertain the function of signals, we have to first uncover the reasons behind signal variation. There are several potential driving forces, including background noise, predation cost, receiver perception, and energy limitations. The energy limitation hypothesis assumes that individuals trade off signal intensity and energy expenditure according to resource condition, while variation of signal intensity likely associates with food availability. This hypothesis has been evidenced by a great number of researches on vocal signals, but no studies evaluated the influence of food availability on motion visual signal in lizards. Here we used an Asian agamid lizard Phrynocephalus vlangalii and examined the effect of food availability on tail display intensity. We designed two food restriction treatments as well as a nature control treatment, and quantified individual tail display speed and display duration under different food availability conditions. Consistent with our prediction, our results showed that males significantly reduced their average tail display speed and maximum display speed in both food restriction treatments when compared to nature control condition. Therefore, our study provides direct evidence that lizards would trade off their display intensity according to the food condition, suggesting tail display is energetically costly and likely provides honest information on individual body condition and resource hold potential.