The phrase "a trending subject" is correct and usable in written English.
You can use it when referring to a topic that is currently popular or widely discussed in media, social networks, or public discourse.
Example: "Climate change has become a trending subject in recent years, sparking debates and discussions worldwide."
Alternatives: "a popular topic" or "a hot issue".
They look for, among other criteria, whether the product category is a trending subject, Twitter-style, on its inventor social network.
It may be absurd the attention the world has given to the reality TV star's new hair colour, but it seems to have become a trending subject worldwide as the 34-year-old sat on the front row of Balmain's show sporting her edgy new look.
The multiverse is a trending subject of investigation among cosmologists and theoretical physicists.
The trending subject is an Instagram post that's being attributed to Franco in which the actor appears to have lashed out against a prominent theater critic.
Dallas Cowboys quarterback Tony Romo was the top trending subject on Twitter after the first Sunday of the new NFL season.
The decision provoked widespread criticism on social media Wednesday evening, with the hashtag #FreeSimmons quickly becoming the top trending subject on Twitter.
His ill-tempered exchange with a Kenyan Twitter user who had urged him not to extend his stay in office spawned a hashtag #someonetellkagame, which was one of the top trending subjects in Kenya.
There seemed to be a trend towards subjects in groups receiving bright light therapy adhering to the study more closely than subjects in the exercise group.
No significant differences were found in the prescriptions by the nature of the mood episode, although there was a trend for subjects with a current depressive episode to be prescribed antidepressants more frequently than other subjects (72% vs. 50%, respectively, χ = 5.9, df = 1, p < 0.02) (Table 3).
We showed a trend for subjects to consume less energy (− 88 ± 61 kcal, P = 0.08) at the buffet after F4, explained by a decrease in lipid intake (P = 0.04).
Although there was no significant effect of rizatriptan on motion-sickness score following the second off-vertical axis rotation, there was a trend for subjects without migraine-related dizziness to show a benefit with rizatriptan as compared to placebo (4 of 5 subjects).
