Jagat Prakash Nadda, India’s minister of health and family welfare, did not respond to repeated requests for comment, but Pawan Agarwal, chief executive of the Food Safety Standards Authority of India, the body in the ministry responsible for such regulations, insisted that the government’s efforts have been sincere.

“This may appear to be typical of India. When you have an issue, you set up so many committees and confuse the whole issue,” he said. But he insisted: “People are concerned. They want to do something about it. Therefore everyone is setting up committees.”

As the case has played out on Twitter and in newspapers, students carrying “Junk Food Rest in Peace” posters have rallied, seeking to make obesity an issue in a country where feeding the hungry has been a national obsession. Some schools have voluntarily stopped serving junk food.

The court battle has unfolded in a grand, wood-paneled courtroom here in the nation’s capital. Mr. Verma, 42, quit his job as a corporate marketing executive after his son’s birth in 2006 and set up a foundation in 2007 to help families like his with sick children. An emotional man, he sometimes wept in frustration with the government’s foot dragging. At one point, doubting his decision to venture into India’s overburdened legal system, the lanky, round-faced Mr. Verma, who wears big square glasses, begged the judge to let him withdraw the petition.

“Nothing is happening. I’ve wasted my time,” he said, tears sliding down his face, as he bemoaned getting sidetracked from his foundation’s mission of helping poor, sick children at the giant public hospital where his son had been treated. “I could have helped hundreds of kids.”

But Chief Justice Dipak Misra refused to let Mr. Verma take back his lawsuit. Instead, spotting a senior advocate, Neeraj Kishan Kaul, at the back of the crowded courtroom, the judge ordered him to act as the pro bono lawyer for Mr. Verma’s case.

As Mr. Kaul, 54, approached the bench, he recalled, he joked to the judge, “You’ve got the wrong guy. I like junk food.”